.cargo/config.toml

@@ -1,2 +1,25 @@
 [alias]
 xtask = "run --manifest-path xtask/Cargo.toml --"
+
+[target.'cfg(all(target_os = "linux", target_arch = "aarch64"))']
+runner = "qemu-aarch64" # May need to remove this if targeting AArch64 from an AArch64 Linux box
+
+[target.aarch64-unknown-linux-gnu]
+linker = "aarch64-linux-gnu-gcc"
+
+[target.aarch64-unknown-linux-musl]
+linker = "aarch64-linux-musl-gcc"
+# AArch64 Linux musl targets are repeatedly affected under varying
+# circumstances by fixedn't linking issues to compiler builtin symbols.
+# Linking to libgcc, though arguably an inelegant hack that's only portable
+# to our glibc from musl crosscompilation scenario, is effective to reliably
+# provide an implementation of those fundamental symbols over time, without
+# user-visible impacts on the final executables. See:
+# https://github.com/rust-lang/rust/issues/46651
+# https://github.com/rust-lang/compiler-builtins/issues/201
+# https://github.com/rust-lang/rust/issues/128401 (the issue most relevant to
+# our observed failures)
+# Note that these flags are not enforced on CI because CI overrides them through
+# the RUSTFLAG environment variable. Check out the CI workflow definition file at
+# .github/workflows/oxipng.yml for more info
+rustflags = ["-Clink-args=-lgcc"]

.dockerignore

@@ -1,7 +1,4 @@
+scripts
+.github
 .editorconfig
-.gitignore
-/.git/
-/.github/
-/.pre-commit-hooks.yaml
-/scripts/
-/target/
+.pre-commit-hooks.yaml

.github/dependabot.yml

@@ -1,24 +1,6 @@
 version: 2
 updates:
-  - package-ecosystem: "cargo"
-    directory: "/"
-    schedule:
-      interval: "weekly"
-    open-pull-requests-limit: 5
-    commit-message:
-      prefix: "chore"
-      include: "scope"
-    labels:
-      - "dependencies"
-      - "rust"
-    groups:
-      rust-dependencies:
-        patterns:
-          - "*"
-        update-types:
-          - "minor"
-          - "patch"
   - package-ecosystem: "github-actions"
     directory: "/"
     schedule:
-      interval: "weekly"
+      interval: monthly

.github/workflows/deploy.yml

@@ -3,12 +3,7 @@ name: deploy
 on:
   push:
     tags:
-      - v*.*.*
-
-concurrency:
-  # If we ever end up with two concurrent jobs for releasing the same tag, the former should be cancelled
-  group: release-${{ github.ref }}
-  cancel-in-progress: true
+      - 'v*.*.*'
 
 permissions:
   actions: read
@@ -25,10 +20,6 @@ jobs:
     if: ${{ !github.event.repository.fork }}
 
     strategy:
-      # Execute one job at a time to avoid potential race conditions in the
-      # GitHub release management APIs. See:
-      # https://github.com/softprops/action-gh-release/issues/445#issuecomment-2407940052
-      max-parallel: 1
       matrix:
         target:
           - x86_64-unknown-linux-gnu
@@ -42,32 +33,18 @@ jobs:
 
     steps:
       - name: Checkout source
-        uses: actions/checkout@v6
-
-      - name: Install Rust toolchain
-        uses: actions-rust-lang/setup-rust-toolchain@v1
-        with:
-          toolchain: nightly
-          cache-bin: false
-          cache-shared-key: cache
-
-      - name: Install cargo-deb
-        if: endsWith(matrix.target, '-linux-gnu')
-        uses: taiki-e/install-action@v2
-        with:
-          tool: cargo-deb
+        uses: actions/checkout@v4
 
       - name: Get the Oxipng version
         id: oxipngMeta
-        run: >
-          echo "version=$(cargo metadata --format-version 1 --no-deps |
-          jq -r '.packages[] | select(.name == "oxipng").version')" >> "$GITHUB_OUTPUT"
+        run: echo "version=$(cargo metadata --format-version 1 --no-deps | jq -r '.packages[] | select(.name == "oxipng").version')"
+          >> "$GITHUB_OUTPUT"
 
       - name: Retrieve ${{ matrix.target }} binary
-        uses: dawidd6/action-download-artifact@v21
+        uses: dawidd6/action-download-artifact@v9
         with:
           workflow: oxipng.yml
-          commit: ${{ github.sha }}
+          commit: ${{ env.GITHUB_SHA }}
           name: Oxipng binary (${{ matrix.target }})
           path: target
 
@@ -94,12 +71,12 @@ jobs:
               # so make the binary world-executable to meet user
               # expectations set by preceding releases.
               # Related issue:
-              # https://github.com/oxipng/oxipng/issues/575
+              # https://github.com/shssoichiro/oxipng/issues/575
               chmod ugo+x "$ARCHIVE_NAME"/oxipng
               tar -vczf "${ARCHIVE_NAME}.tar.gz" "$ARCHIVE_NAME"/*;;
           esac
 
-      - name: Install AArch64 libc components
+      - name: Install QEMU and AArch64 cross compiler
         if: matrix.target == 'aarch64-unknown-linux-gnu'
         run: |
           sudo apt-get -yq update
@@ -108,27 +85,19 @@ jobs:
           # properly
           sudo apt-get -yq install libc6-arm64-cross libgcc-s1-arm64-cross
 
-      - name: Build Debian packages
+      - name: Build deb archives
         if: endsWith(matrix.target, '-linux-gnu')
-        env:
-          # The *-arm64-cross packages above install AArch64 libraries in
-          # /usr/<arch>/lib instead of /usr/lib/<arch>, as expected by
-          # cargo-deb and dpkg-shlibdeps to find such shared libraries.
-          # Make both of them visible to such commands by adding that directory
-          # to the dynamic linker's library search path. See:
-          # - <https://man7.org/linux/man-pages/man1/dpkg-shlibdeps.1.html> ("Errors" section)
-          # - <https://github.com/kornelski/cargo-deb/issues/21>
-          LD_LIBRARY_PATH: /usr/aarch64-linux-gnu/lib
         run: |
           mkdir -p "target/${{ matrix.target }}/release"
           mv target/oxipng "target/${{ matrix.target }}/release"
+          cargo install --locked cargo-deb
           cargo deb --target "${{ matrix.target }}" --no-build --no-strip
 
       - name: Create release notes
         run: tail -n +3 CHANGELOG.md | sed -e '/^$/,$d' > RELEASE_NOTES.txt
 
       - name: Create release
-        uses: softprops/action-gh-release@v3
+        uses: softprops/action-gh-release@v2
         with:
           name: v${{ steps.oxipngMeta.outputs.version }}
           body_path: RELEASE_NOTES.txt

.github/workflows/docker.yml

@@ -2,9 +2,9 @@ name: docker
 on:
   push:
     branches:
-      - master
+      - 'master'
     tags:
-      - v*.*.*
+      - 'v*.*.*'
   pull_request:
     types:
       - opened
@@ -17,44 +17,76 @@ on:
         type: boolean
         default: true
 
-concurrency:
-  # If we ever end up with two concurrent Docker build jobs for the same commit
-  # and same versioning context, the former should be cancelled
-  group: docker-${{ github.sha }}-${{ github.ref_type }}-${{ github.head_ref }}
-  cancel-in-progress: true
+env:
+  REGISTRY: ghcr.io
+  # ghcr.io/OWNER/REPO
+  IMAGE_NAME: ${{ github.repository }}
 
 jobs:
   build:
-    uses: docker/github-builder/.github/workflows/build.yml@v1
+    runs-on: ubuntu-latest
     permissions:
       contents: read
       packages: write
       id-token: write
       attestations: write
-    with:
-      output: image
-      platforms: linux/amd64,linux/arm64
-      push: ${{ github.event_name != 'pull_request' }}
-      cache: ${{ github.event_name != 'workflow_dispatch' || inputs.use_cache }}
-      # We don't sign the image because ghcr.io doesn't support OCI Referrers API yet, and the fallback relies on pushing new tags on each build
-      # https://github.com/docker/github-builder/issues/109#issuecomment-3885082486
-      # https://github.com/opencontainers/distribution-spec/blob/v1.1.0/spec.md#backwards-compatibility
-      sign: false
-      sbom: true
-      meta-images: ghcr.io/${{ github.repository }}
-      meta-tags: |
-        type=ref,event=branch
-        type=ref,event=pr
-        type=semver,pattern={{raw}}
-      set-meta-annotations: true
-      set-meta-labels: true
-      labels: |
-        org.opencontainers.image.title=Oxipng
-      annotations: |
-        org.opencontainers.image.title=Oxipng
 
-    secrets:
-      registry-auths: |
-        - registry: ghcr.io
+    steps:
+      - name: Checkout repository
+        uses: actions/checkout@v4
+
+      - name: Set up QEMU
+        uses: docker/setup-qemu-action@v3
+
+      # Workaround: https://github.com/docker/build-push-action/issues/461
+      - name: Setup Docker buildx
+        uses: docker/setup-buildx-action@v3
+
+      # Login against a Docker registry except on PR
+      # https://github.com/docker/login-action
+      - name: Log into registry ${{ env.REGISTRY }}
+        if: github.event_name != 'pull_request'
+        uses: docker/login-action@v3
+        with:
+          registry: ${{ env.REGISTRY }}
           username: ${{ github.actor }}
           password: ${{ secrets.GITHUB_TOKEN }}
+
+      # Extract metadata (tags, labels) for Docker
+      # For some reason the title have to be set manually
+      # https://github.com/docker/metadata-action
+      - name: Extract Docker metadata
+        id: meta
+        uses: docker/metadata-action@v5
+        with:
+          images: ${{ env.REGISTRY }}/${{ env.IMAGE_NAME }}
+          labels: |
+            org.opencontainers.image.title=Oxipng
+          annotations: |
+            org.opencontainers.image.title=Oxipng
+
+      # Build and push Docker image with Buildx (don't push on PR)
+      # Cache isn't used for tags and on workflow_dispatch if specified
+      # https://github.com/docker/build-push-action
+      - name: Build and push Docker image
+        id: build-and-push
+        uses: docker/build-push-action@v6
+        with:
+          context: .
+          platforms: linux/amd64,linux/arm64
+          push: ${{ github.event_name != 'pull_request' }}
+          tags: ${{ steps.meta.outputs.tags }}
+          labels: ${{ steps.meta.outputs.labels }}
+          cache-from: type=gha
+          cache-to: type=gha,mode=max
+          no-cache: ${{ (github.event_name == 'workflow_dispatch' && !inputs.use_cache) || startsWith(github.ref, 'refs/tags/') }}
+
+      # Attest the build provenance
+      # TODO: enable push to registry when referrers API will be supported by ghcr.io
+      - name: Attest Build Provenance
+        if: github.event_name != 'pull_request'
+        uses: actions/attest-build-provenance@v2
+        with:
+          subject-name: ${{ env.REGISTRY }}/${{ env.IMAGE_NAME }}
+          subject-digest: ${{ steps.build-and-push.outputs.digest }}
+          push-to-registry: false

.github/workflows/oxipng.yml

@@ -8,11 +8,6 @@ on:
       - synchronize
   workflow_dispatch:
 
-concurrency:
-  # If we ever end up with two concurrent CI jobs for the same commit, the former should be cancelled
-  group: ci-${{ github.sha }}
-  cancel-in-progress: true
-
 jobs:
   ci:
     name: CI
@@ -38,49 +33,73 @@ jobs:
 
         include:
           - target: x86_64-unknown-linux-gnu
-            os: ubuntu-24.04
+            os: ubuntu-22.04
             target-apt-arch: amd64
           - target: x86_64-unknown-linux-musl
-            os: ubuntu-24.04
+            os: ubuntu-22.04
             target-apt-arch: amd64
           - target: aarch64-unknown-linux-gnu
-            os: ubuntu-24.04-arm
+            os: ubuntu-22.04
             target-apt-arch: arm64
           - target: aarch64-unknown-linux-musl
-            os: ubuntu-24.04-arm
+            os: ubuntu-22.04
             target-apt-arch: arm64
           - target: x86_64-pc-windows-msvc
             os: windows-latest
           - target: i686-pc-windows-msvc
             os: windows-latest
           - target: x86_64-apple-darwin
-            os: macos-15
+            os: macos-13 # x86_64 runner
           - target: aarch64-apple-darwin
-            os: macos-15
+            os: macos-14 # ARM64 runner
 
     env:
       CARGO_BUILD_TARGET: ${{ matrix.target }}
+      # Hopefully temporary workaround for https://github.com/rust-lang/rust/issues/128401
+      # See the comments for similar rustflag settings at .cargo/config.toml for more context
+      RUSTFLAGS: ${{ matrix.target == 'aarch64-unknown-linux-musl' && '-Zlocation-detail=none -Clink-args=-lgcc' || '-Zlocation-detail=none' }}
 
     steps:
       - name: Checkout source
-        uses: actions/checkout@v6
+        uses: actions/checkout@v4
         with:
           persist-credentials: false
 
+      - name: Set up Ubuntu multiarch
+        if: startsWith(matrix.os, 'ubuntu') && matrix.target-apt-arch != 'amd64'
+        run: |
+          readonly DISTRO_CODENAME=jammy
+          sudo dpkg --add-architecture "${{ matrix.target-apt-arch }}"
+          sudo sed -i "s/^deb http/deb [arch=$(dpkg-architecture -q DEB_HOST_ARCH)] http/" /etc/apt/sources.list
+          sudo sed -i "s/^deb mirror/deb [arch=$(dpkg-architecture -q DEB_HOST_ARCH)] mirror/" /etc/apt/sources.list
+          for suite in '' '-updates' '-backports' '-security'; do
+            echo "deb [arch=${{ matrix.target-apt-arch }}] http://ports.ubuntu.com/ $DISTRO_CODENAME$suite main universe multiverse" | \
+            sudo tee -a /etc/apt/sources.list >/dev/null
+          done
+
       - name: Install musl development files
         if: endsWith(matrix.target, '-musl')
         run: |
           sudo apt-get -yq update
           sudo apt-get -yq install musl-tools musl-dev:${{ matrix.target-apt-arch }}
 
+      - name: Install QEMU and AArch64 cross compiler
+        if: startsWith(matrix.target, 'aarch64-unknown-linux')
+        run: |
+          sudo apt-get -yq update
+          # libc6 must be present to run executables dynamically linked
+          # against glibc for the target architecture
+          sudo apt-get -yq install qemu-user gcc-aarch64-linux-gnu libc6:arm64
+
+      - name: Cache Cargo artifacts
+        uses: Swatinem/rust-cache@v2
+
       - name: Install Rust toolchain
-        uses: actions-rust-lang/setup-rust-toolchain@v1
+        uses: dtolnay/rust-toolchain@v1
         with:
           toolchain: nightly
-          target: ${{ env.CARGO_BUILD_TARGET }}
-          components: clippy, rustfmt, rust-src
-          cache-bin: false
-          cache-shared-key: cache
+          targets: ${{ env.CARGO_BUILD_TARGET }}
+          components: clippy, rustfmt
 
       - name: Install nextest
         uses: taiki-e/install-action@nextest
@@ -129,12 +148,10 @@ jobs:
         run: cargo doc --release --no-deps
 
       - name: Build CLI binary
-        run: cargo build --release -Zbuild-std
-        env:
-          RUSTFLAGS: "-Zlocation-detail=none -Zunstable-options -Cpanic=immediate-abort"
+        run: cargo build --release
 
       - name: Upload CLI binary as artifact
-        uses: actions/upload-artifact@v7
+        uses: actions/upload-artifact@v4
         with:
           name: Oxipng binary (${{ matrix.target }})
           path: |
@@ -142,7 +159,7 @@ jobs:
             target/${{ env.CARGO_BUILD_TARGET }}/release/oxipng.exe
 
       - name: Upload analysis results to GitHub
-        uses: github/codeql-action/upload-sarif@v4
+        uses: github/codeql-action/upload-sarif@v3
         if: always() && matrix.target == 'x86_64-unknown-linux-gnu'
         continue-on-error: true
         with:
@@ -160,16 +177,15 @@ jobs:
 
     steps:
       - name: Checkout source
-        uses: actions/checkout@v6
+        uses: actions/checkout@v4
         with:
           persist-credentials: false
 
+      - name: Cache Cargo artifacts
+        uses: Swatinem/rust-cache@v2
+
       - name: Install MSRV Rust toolchain
-        uses: actions-rust-lang/setup-rust-toolchain@v1
-        with:
-          toolchain: 1.85.1
-          cache-bin: false
-          cache-shared-key: cache
+        uses: dtolnay/rust-toolchain@1.74.0
 
       - name: Install nextest
         uses: taiki-e/install-action@nextest

.gitignore

@@ -1,6 +1,6 @@
-.DS_Store
+target
 *.bk
+.DS_Store
 *.out.png
-/.idea/
-/node_modules/
-/target/
+/.idea
+/node_modules

CHANGELOG.md

@@ -1,36 +1,3 @@
-## Version 10.1.1
-
-- [Performance] Improve Bigrams performance, giving notably faster results at lower levels.
-- [Improvement] Change `--np` flag to also prevent conversion to indexed from other color types.
-- [Improvement] Improve support for recompressing ICC profiles with high compression ratios.
-- [Misc] Add warning when `--ziwi` exceeds `--zi`.
-- [Build] Further reduce size of binaries.
-
-## Version 10.1.0
-
-- [Feature] Add `--json` option for machine-readable output.
-- [Improvement] New default output with file counter and summary. (Use an extra `-v` flag to get the same output as before.)
-- [Bugfix] Fix fast mode sometimes giving suboptimal results for small, indexed images.
-
-## Version 10.0.0
-
-- [Breaking] CLI: Change short zopfli flag from `-Z` to `-z`.
-- [Breaking] CLI: Change `--pretend`/`-P` to `--dry-run`/`-d`.
-- [Breaking] CLI: Change `--interlace` options from `1`/`0` to `on`/`off`.
-- [Breaking] API: Change `Options.interlace: Option<Interlacing>` to `Options.interlace: Option<bool>`.
-- [Breaking] API: Change `Options.filter: IndexSet<RowFilter>` to `Options.filters: IndexSet<FilterStrategy>`.
-- [Breaking] API: Change `Options.deflate: Deflaters` to `Options.deflater: Deflater`.
-- [Breaking] API: Change `Deflaters::Zopfli { .. }` to `Deflater::Zopfli(ZopfliOptions { .. })`.
-- [Breaking] API: Change `optimize()` to return `(usize, usize)`, with original and optimized sizes.
-- [Feature] Allow zopfli iterations higher than 255.
-- [Feature] Add `--ziwi` option for zopfli iterations without improvement.
-- [Feature] Add `--max-raw-size` option to skip images that are too large.
-- [Feature] Add `--brute-level` and `--brute-lines` options for advanced control of Brute filter.
-- [Improvement] Reduce memory usage for `fast` mode.
-- [Improvement] Slightly improve compression with Brute filter at levels 5 and 6.
-- [Misc] Change `--preserve` option to no longer preserve last access time.
-- [Misc] Make help output colored.
-
 ## Version 9.1.5
 
 - [Feature] Add `--sequential` option to process files sequentially rather than in parallel.
@@ -199,51 +166,51 @@
 ### Version 3.0.0
 
 - [Breaking] Bump minimum Rust version to 1.41.0
-- [Breaking] Use IndexMap/IndexSet to provide more consistent performance ([#202](https://github.com/oxipng/oxipng/pull/202))
+- [Breaking] Use IndexMap/IndexSet to provide more consistent performance ([#202](https://github.com/shssoichiro/oxipng/pull/202))
   - This changes some public-facing types.
     `IndexMap` and `IndexSet` are reexported
     at the crate root to aid migration.
-- [Breaking] Remove fields from the `Options` struct which were never used ([#211](https://github.com/oxipng/oxipng/pull/211/files#diff-b4aea3e418ccdb71239b96952d9cddb6L217), [#212](https://github.com/oxipng/oxipng/pull/212/files#diff-b4aea3e418ccdb71239b96952d9cddb6L134))
-- [Breaking] Refactor zlib-specific options in the `Options` struct ([#210](https://github.com/oxipng/oxipng/pull/210/files))
-- [Feature] Add libdeflater as an option ([#203](https://github.com/oxipng/oxipng/pull/203))
-- [Feature] Use standard `log` library ([#218](https://github.com/oxipng/oxipng/pull/218))
-- [Feature] Add `-o max` setting which will always reference the highest compression preset ([#224](https://github.com/oxipng/oxipng/pull/224))
+- [Breaking] Remove fields from the `Options` struct which were never used ([#211](https://github.com/shssoichiro/oxipng/pull/211/files#diff-b4aea3e418ccdb71239b96952d9cddb6L217), [#212](https://github.com/shssoichiro/oxipng/pull/212/files#diff-b4aea3e418ccdb71239b96952d9cddb6L134))
+- [Breaking] Refactor zlib-specific options in the `Options` struct ([#210](https://github.com/shssoichiro/oxipng/pull/210/files))
+- [Feature] Add libdeflater as an option ([#203](https://github.com/shssoichiro/oxipng/pull/203))
+- [Feature] Use standard `log` library ([#218](https://github.com/shssoichiro/oxipng/pull/218))
+- [Feature] Add `-o max` setting which will always reference the highest compression preset ([#224](https://github.com/shssoichiro/oxipng/pull/224))
 - [Deprecated] `-o 4` was found to be equivalent to `-o 3` and is deprecated.
   It will likely be removed in a future release.
-  For now it remains equivalent to `-o 3`. ([#224](https://github.com/oxipng/oxipng/pull/224))
-- [Bugfix] Ensure output is deterministic ([#199](https://github.com/oxipng/oxipng/pull/199))
+  For now it remains equivalent to `-o 3`. ([#224](https://github.com/shssoichiro/oxipng/pull/224))
+- [Bugfix] Ensure output is deterministic ([#199](https://github.com/shssoichiro/oxipng/pull/199))
 - Update `image` crate to 0.23
 - Update `itertools` crate to 0.9
 - Various performance and internal improvements
 
 ### Version 2.3.0
 
-- Allow disabling all alpha optimizations ([#181](https://github.com/oxipng/oxipng/pull/181))
-- Fix interlacing issues on tiny images ([#182](https://github.com/oxipng/oxipng/pull/182))
-- Reduce memory usage in filtering ([#191](https://github.com/oxipng/oxipng/pull/191))
-- Implement palette sorting to improve compression ([#193](https://github.com/oxipng/oxipng/pull/193))
-- Disable alpha optimizations by default ([#187](https://github.com/oxipng/oxipng/pull/187))
-- Add support for WASM ([#194](https://github.com/oxipng/oxipng/pull/194))
+- Allow disabling all alpha optimizations ([#181](https://github.com/shssoichiro/oxipng/pull/181))
+- Fix interlacing issues on tiny images ([#182](https://github.com/shssoichiro/oxipng/pull/182))
+- Reduce memory usage in filtering ([#191](https://github.com/shssoichiro/oxipng/pull/191))
+- Implement palette sorting to improve compression ([#193](https://github.com/shssoichiro/oxipng/pull/193))
+- Disable alpha optimizations by default ([#187](https://github.com/shssoichiro/oxipng/pull/187))
+- Add support for WASM ([#194](https://github.com/shssoichiro/oxipng/pull/194))
 
 ### Version 2.2.2
 
-- Fix grayscale bit-depth reduction ([#171](https://github.com/oxipng/oxipng/pull/171))
-- Fix typos and incorrect log message ([#172](https://github.com/oxipng/oxipng/pull/172))
-- Make metadata order deterministic ([#174](https://github.com/oxipng/oxipng/pull/174))
-- Fix 32-bit builds ([#176](https://github.com/oxipng/oxipng/pull/176))
-- Enable LTO in release builds ([#177](https://github.com/oxipng/oxipng/pull/177))
-- Use deterministic compression strategy ([#179](https://github.com/oxipng/oxipng/pull/179))
-- Fix decoding interlaced images with height or width <= 2 ([#175](https://github.com/oxipng/oxipng/pull/175))
-- Preallocate memory in reduced_alpha_to_up ([#180](https://github.com/oxipng/oxipng/pull/180))
+- Fix grayscale bit-depth reduction ([#171](https://github.com/shssoichiro/oxipng/pull/171))
+- Fix typos and incorrect log message ([#172](https://github.com/shssoichiro/oxipng/pull/172))
+- Make metadata order deterministic ([#174](https://github.com/shssoichiro/oxipng/pull/174))
+- Fix 32-bit builds ([#176](https://github.com/shssoichiro/oxipng/pull/176))
+- Enable LTO in release builds ([#177](https://github.com/shssoichiro/oxipng/pull/177))
+- Use deterministic compression strategy ([#179](https://github.com/shssoichiro/oxipng/pull/179))
+- Fix decoding interlaced images with height or width <= 2 ([#175](https://github.com/shssoichiro/oxipng/pull/175))
+- Preallocate memory in reduced_alpha_to_up ([#180](https://github.com/shssoichiro/oxipng/pull/180))
 - Update `bit-vec` crate to 0.6
 
 ### Version 2.2.1
 
-- Fix compression of very large files ([#167](https://github.com/oxipng/oxipng/pull/167)) ([#168](https://github.com/oxipng/oxipng/pull/168))
+- Fix compression of very large files ([#167](https://github.com/shssoichiro/oxipng/pull/167)) ([#168](https://github.com/shssoichiro/oxipng/pull/168))
 
 ### Version 2.2.0
 
-- Various internal improvements ([#154](https://github.com/oxipng/oxipng/pull/154)) ([#158](https://github.com/oxipng/oxipng/pull/158)) ([#160](https://github.com/oxipng/oxipng/pull/160)) ([#161](https://github.com/oxipng/oxipng/pull/161)) ([#162](https://github.com/oxipng/oxipng/pull/162)) ([#163](https://github.com/oxipng/oxipng/pull/163))
+- Various internal improvements ([#154](https://github.com/shssoichiro/oxipng/pull/154)) ([#158](https://github.com/shssoichiro/oxipng/pull/158)) ([#160](https://github.com/shssoichiro/oxipng/pull/160)) ([#161](https://github.com/shssoichiro/oxipng/pull/161)) ([#162](https://github.com/shssoichiro/oxipng/pull/162)) ([#163](https://github.com/shssoichiro/oxipng/pull/163))
 - Update `image` crate to 0.21.0
 - Update `itertools` crate to 0.8.0
 - Update `zopfli` crate to 0.4.0
@@ -252,24 +219,24 @@
 
 ### Version 2.1.8
 
-- Fix non-standard sBIT headers in other code locations ([#153](https://github.com/oxipng/oxipng/issues/153))
+- Fix non-standard sBIT headers in other code locations ([#153](https://github.com/shssoichiro/oxipng/issues/153))
 
 ### Version 2.1.7
 
-- 80x faster palette reduction ([#150](https://github.com/oxipng/oxipng/pull/150))
-- Optimize RGB to palette conversion ([#148](https://github.com/oxipng/oxipng/pull/148))
-- Various microoptimizations ([#146](https://github.com/oxipng/oxipng/pull/146))
-- Introduce third-party safe wrapper around cloudflare-zlib ([#149](https://github.com/oxipng/oxipng/pull/149))
+- 80x faster palette reduction ([#150](https://github.com/shssoichiro/oxipng/pull/150))
+- Optimize RGB to palette conversion ([#148](https://github.com/shssoichiro/oxipng/pull/148))
+- Various microoptimizations ([#146](https://github.com/shssoichiro/oxipng/pull/146))
+- Introduce third-party safe wrapper around cloudflare-zlib ([#149](https://github.com/shssoichiro/oxipng/pull/149))
 
 ### Version 2.1.6
 
-- Identify and drop useless sRGB profiles ([#143](https://github.com/oxipng/oxipng/pull/143))
-- Alpha heuristic improvements ([#144](https://github.com/oxipng/oxipng/pull/144))
+- Identify and drop useless sRGB profiles ([#143](https://github.com/shssoichiro/oxipng/pull/143))
+- Alpha heuristic improvements ([#144](https://github.com/shssoichiro/oxipng/pull/144))
 - Bump `miniz_oxide` and `cloudflare-zlib-sys` to 0.2.0
 
 ### Version 2.1.5
 
-- Fix issue where some images will incorrectly reduce bit depth ([#140](https://github.com/oxipng/oxipng/issues/140))
+- Fix issue where some images will incorrectly reduce bit depth ([#140](https://github.com/shssoichiro/oxipng/issues/140))
 
 ### Version 2.1.4
 
@@ -282,22 +249,22 @@
 
 ### Version 2.1.2
 
-- Fix issue with PNG to Indexed reduction on images with transparency pixel ([#129](https://github.com/oxipng/oxipng/issues/129))
+- Fix issue with PNG to Indexed reduction on images with transparency pixel ([#129](https://github.com/shssoichiro/oxipng/issues/129))
 
 ### Version 2.1.1
 
-- More fixes for alpha optimization on interlaced images ([#133](https://github.com/oxipng/oxipng/issues/133))
+- More fixes for alpha optimization on interlaced images ([#133](https://github.com/shssoichiro/oxipng/issues/133))
 
 ### Version 2.1.0
 
 - [SEMVER_MINOR] Bump minimum Rust version to 1.27.0
 - [SEMVER_MINOR] Reenable faster Cloudflare zlib compression on platforms that support it
-- Fix memory leak with Cloudflare zlib ([#126](https://github.com/oxipng/oxipng/issues/126))
+- Fix memory leak with Cloudflare zlib ([#126](https://github.com/shssoichiro/oxipng/issues/126))
 - Minor fixes and cleanup
 
 ### Version 2.0.2
 
-- Fix an issue in alpha optimization on interlaced images ([#113](https://github.com/oxipng/oxipng/issues/113))
+- Fix an issue in alpha optimization on interlaced images ([#113](https://github.com/shssoichiro/oxipng/issues/113))
 
 ### Version 2.0.1
 
@@ -334,12 +301,12 @@
 
 ### Version 1.0.1
 
-- Bump rayon to 1.0 ([#99](https://github.com/oxipng/oxipng/pull/99) @cuviper)
+- Bump rayon to 1.0 ([#99](https://github.com/shssoichiro/oxipng/pull/99) @cuviper)
 - Bump minor versions of other dependencies for binary distribution
 
 ### Version 1.0.0
 
-- Remove the C dependency on miniz, and replace it with a Rust version ([#57](https://github.com/oxipng/oxipng/issues/57))
+- Remove the C dependency on miniz, and replace it with a Rust version ([#57](https://github.com/shssoichiro/oxipng/issues/57))
   - This improves decompression speed by 15%. Compression speed is not affected.
   - [SEMVER_MAJOR] This also obsoletes the `-zm` command line option and the `memory` key on the `Options` struct.
   - Presets will be updated automatically. This means that presets 3 and higher will run significantly more quickly.
@@ -366,30 +333,30 @@
 
 ### Version 0.18.3
 
-- Return exit code of 1 if an error occurred while processing a file using the CLI app ([#93](https://github.com/oxipng/oxipng/issues/93))
+- Return exit code of 1 if an error occurred while processing a file using the CLI app ([#93](https://github.com/shssoichiro/oxipng/issues/93))
 
 ### Version 0.18.2
 
 - Bump `image` to 0.18
-- Fix unfiltering of scan lines in interlaced images ([#92](https://github.com/oxipng/oxipng/issues/92))
+- Fix unfiltering of scan lines in interlaced images ([#92](https://github.com/shssoichiro/oxipng/issues/92))
 
 ### Version 0.18.1
 
 - Bump `rayon` to 0.9
-- Fix failure to optimize on certain grayscale images ([#89](https://github.com/oxipng/oxipng/issues/89))
+- Fix failure to optimize on certain grayscale images ([#89](https://github.com/shssoichiro/oxipng/issues/89))
 
 ### Version 0.18.0
 
 - Bump `itertools` to 0.7
 - Bump `image` to 0.17
 - [SEMVER_MAJOR] Bump minimum rustc version to 1.20.0
-- Fix parsing of glob paths on Windows ([#90](https://github.com/oxipng/oxipng/issues/90))
+- Fix parsing of glob paths on Windows ([#90](https://github.com/shssoichiro/oxipng/issues/90))
 
 ### Version 0.17.2
 
 - Bump `image` to 0.16
-- Quickly pass over files that do not have a PNG header ([#85](https://github.com/oxipng/oxipng/issues/85) @emielbeinema)
-- Return an error instead of crashing on APNG files ([#83](https://github.com/oxipng/oxipng/issues/83) @emielbeinema)
+- Quickly pass over files that do not have a PNG header ([#85](https://github.com/shssoichiro/oxipng/issues/85) @emielbeinema)
+- Return an error instead of crashing on APNG files ([#83](https://github.com/shssoichiro/oxipng/issues/83) @emielbeinema)
 
 ### Version 0.17.1
 
@@ -405,14 +372,14 @@
   trials for optimizing the alpha channel, using the previously mentioned fast heuristic.
   This option will make optimization of images with transparency somewhat slower,
   but may improve compression.
-- Fixed a bug in reducing palettes for images with bit depth of two ([#80](https://github.com/oxipng/oxipng/issues/80))
-- Fixed another bug in reducing palettes for images with bit depth less than eight ([#82](https://github.com/oxipng/oxipng/issues/82))
+- Fixed a bug in reducing palettes for images with bit depth of two ([#80](https://github.com/shssoichiro/oxipng/issues/80))
+- Fixed another bug in reducing palettes for images with bit depth less than eight ([#82](https://github.com/shssoichiro/oxipng/issues/82))
 - Code cleanup
 - Bump `image` to 0.15
 
 ### Version 0.16.3
 
-- Fix command-line help text ([#70](https://github.com/oxipng/oxipng/issues/70))
+- Fix command-line help text ([#70](https://github.com/shssoichiro/oxipng/issues/70))
 
 ### Version 0.16.2
 
@@ -430,18 +397,18 @@
 
 ### Version 0.15.2
 
-- Bump `image` to 0.13 ([#65](https://github.com/oxipng/oxipng/pull/65))
+- Bump `image` to 0.13 ([#65](https://github.com/shssoichiro/oxipng/pull/65))
 - Bump `rayon` to 0.7
 - Bump `itertools` to 0.6
 
 ### Version 0.15.1
 
-- Ignore color reductions that would increase file size ([#61](https://github.com/oxipng/oxipng/issues/61))
+- Ignore color reductions that would increase file size ([#61](https://github.com/shssoichiro/oxipng/issues/61))
 
 ### Version 0.15.0
 
-- [SEMVER_MINOR] Check images for correctness before writing result ([#60](https://github.com/oxipng/oxipng/issues/60))
-- Fix invalid output when reducing image to a different color type but file size does not improve ([#60](https://github.com/oxipng/oxipng/issues/60))
+- [SEMVER_MINOR] Check images for correctness before writing result ([#60](https://github.com/shssoichiro/oxipng/issues/60))
+- Fix invalid output when reducing image to a different color type but file size does not improve ([#60](https://github.com/shssoichiro/oxipng/issues/60))
 - Don't write new file if moving from interlaced to non-interlaced if new file would be larger
 
 ### Version 0.14.4
@@ -475,14 +442,14 @@
 
 ### Version 0.13.0
 
-- Fix bug in certain PNG headers when reducing color type ([#52](https://github.com/oxipng/oxipng/issues/52))
+- Fix bug in certain PNG headers when reducing color type ([#52](https://github.com/shssoichiro/oxipng/issues/52))
 - [SEMVER_MAJOR] Reduction functions now take `&mut PngData` and return a `bool` indicating whether the image was reduced
 - [SMEVER_MAJOR] Bump minimum required rustc version to 1.12.0
 
 ### Version 0.12.0
 
 - Performance optimizations
-- Fix processing filenames that contain commas (@aliceatlas [#50](https://github.com/oxipng/oxipng/pull/50))
+- Fix processing filenames that contain commas (@aliceatlas [#50](https://github.com/shssoichiro/oxipng/pull/50))
 - [SEMVER_MINOR] Add zopfli option (-Z), disabled by default. Gives about 10% better compression, but is currently 50-100x slower.
 
 ### Version 0.11.0
@@ -507,7 +474,7 @@
 
 ### Version 0.8.2
 
-- Fix issue where images smaller than 4px width would crash on interlacing ([#42](https://github.com/oxipng/oxipng/issues/42))
+- Fix issue where images smaller than 4px width would crash on interlacing ([#42](https://github.com/shssoichiro/oxipng/issues/42))
 
 ### Version 0.8.1
 
@@ -523,7 +490,7 @@
 - Minor compression improvement on interlaced images
 - Performance optimizations
 - [SEMVER_MINOR] Move default Options into a Default impl
-- [SEMVER_MINOR] Add option for setting number of threads ([#39](https://github.com/oxipng/oxipng/issues/39))
+- [SEMVER_MINOR] Add option for setting number of threads ([#39](https://github.com/shssoichiro/oxipng/issues/39))
 
 ### Version 0.6.0
 
@@ -534,47 +501,47 @@
 
 ### Version 0.5.0
 
-- [SEMVER_MINOR] Palette entries can now reduced, on by default ([#11](https://github.com/oxipng/oxipng/issues/11))
+- [SEMVER_MINOR] Palette entries can now reduced, on by default ([#11](https://github.com/shssoichiro/oxipng/issues/11))
 - Don't report that we are in pretend mode if verbosity is set to none
-- Add cargo bench suite ([#7](https://github.com/oxipng/oxipng/issues/7))
+- Add cargo bench suite ([#7](https://github.com/shssoichiro/oxipng/issues/7))
 
 ### Version 0.4.0
 
 - Performance optimizations
-- [SEMVER_MAJOR] `-s` automatically infers `--strip safe` ([#31](https://github.com/oxipng/oxipng/issues/31))
+- [SEMVER_MAJOR] `-s` automatically infers `--strip safe` ([#31](https://github.com/shssoichiro/oxipng/issues/31))
 - Update byteorder and clap crates
 - Fix issue where interlaced images incorrectly applied filters on the first line of a pass
 
 ### Version 0.3.0
 
 - Properly decode interlaced images
-- [SEMVER_MINOR] Allow converting between progressive and interlaced images ([#3](https://github.com/oxipng/oxipng/issues/3))
+- [SEMVER_MINOR] Allow converting between progressive and interlaced images ([#3](https://github.com/shssoichiro/oxipng/issues/3))
 - Fix a bug that would cause oxipng to crash on very small images
 
 ### Version 0.2.2
 
 - Limit number of threads to 1.5x number of cores
-- Significantly improve memory usage, especially with high optimization levels. ([#32](https://github.com/oxipng/oxipng/issues/32))
-- Refactor output code ([#19](https://github.com/oxipng/oxipng/issues/19))
+- Significantly improve memory usage, especially with high optimization levels. ([#32](https://github.com/shssoichiro/oxipng/issues/32))
+- Refactor output code ([#19](https://github.com/shssoichiro/oxipng/issues/19))
 
 ### Version 0.2.1
 
 - Add rustdoc for public methods and structs
-- Improve filter mode 5 heuristic ([#16](https://github.com/oxipng/oxipng/issues/16))
-- Add tests for edge-case images with subtitles ([#29](https://github.com/oxipng/oxipng/issues/29))
+- Improve filter mode 5 heuristic ([#16](https://github.com/shssoichiro/oxipng/issues/16))
+- Add tests for edge-case images with subtitles ([#29](https://github.com/shssoichiro/oxipng/issues/29))
 
 ### Version 0.2.0
 
 - Fix program version that is displayed when running `oxipng -V`
-- Ensure `--quiet` mode is actually quiet (@SethDusek [#20](https://github.com/oxipng/oxipng/pull/20))
+- Ensure `--quiet` mode is actually quiet (@SethDusek [#20](https://github.com/shssoichiro/oxipng/pull/20))
 - Write status/debug information to stderr instead of stdout
-- Use heuristics to determine best combination for `-o1` ([#21](https://github.com/oxipng/oxipng/issues/21))
+- Use heuristics to determine best combination for `-o1` ([#21](https://github.com/shssoichiro/oxipng/issues/21))
 - [SEMVER_MAJOR] Allow 'safe', 'all', or comma-separated list as options for `--strip`
 - [SEMVER_MINOR] Add `-s` alias for `--strip`
 
 ### Version 0.1.1
 
-- Fix `oxipng *` writing all input files to one output file ([#15](https://github.com/oxipng/oxipng/issues/15))
+- Fix `oxipng *` writing all input files to one output file ([#15](https://github.com/shssoichiro/oxipng/issues/15))
 
 ### Version 0.1.0
 

Cargo.lock

@@ -1,18 +1,18 @@
 # This file is automatically @generated by Cargo.
 # It is not intended for manual editing.
-version = 4
+version = 3
 
 [[package]]
 name = "adler2"
-version = "2.0.1"
+version = "2.0.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "320119579fcad9c21884f5c4861d16174d0e06250625266f50fe6898340abefa"
+checksum = "512761e0bb2578dd7380c6baaa0f4ce03e84f95e960231d1dec8bf4d7d6e2627"
 
 [[package]]
 name = "anstream"
-version = "1.0.0"
+version = "0.6.18"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "824a212faf96e9acacdbd09febd34438f8f711fb84e09a8916013cd7815ca28d"
+checksum = "8acc5369981196006228e28809f761875c0327210a891e941f4c683b3a99529b"
 dependencies = [
  "anstyle",
  "anstyle-parse",
@@ -25,50 +25,56 @@ dependencies = [
 
 [[package]]
 name = "anstyle"
-version = "1.0.14"
+version = "1.0.10"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "940b3a0ca603d1eade50a4846a2afffd5ef57a9feac2c0e2ec2e14f9ead76000"
+checksum = "55cc3b69f167a1ef2e161439aa98aed94e6028e5f9a59be9a6ffb47aef1651f9"
 
 [[package]]
 name = "anstyle-parse"
-version = "1.0.0"
+version = "0.2.6"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "52ce7f38b242319f7cabaa6813055467063ecdc9d355bbb4ce0c68908cd8130e"
+checksum = "3b2d16507662817a6a20a9ea92df6652ee4f94f914589377d69f3b21bc5798a9"
 dependencies = [
  "utf8parse",
 ]
 
 [[package]]
 name = "anstyle-query"
-version = "1.1.5"
+version = "1.1.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "40c48f72fd53cd289104fc64099abca73db4166ad86ea0b4341abe65af83dadc"
+checksum = "79947af37f4177cfead1110013d678905c37501914fba0efea834c3fe9a8d60c"
 dependencies = [
  "windows-sys",
 ]
 
 [[package]]
 name = "anstyle-wincon"
-version = "3.0.11"
+version = "3.0.7"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "291e6a250ff86cd4a820112fb8898808a366d8f9f58ce16d1f538353ad55747d"
+checksum = "ca3534e77181a9cc07539ad51f2141fe32f6c3ffd4df76db8ad92346b003ae4e"
 dependencies = [
  "anstyle",
- "once_cell_polyfill",
+ "once_cell",
  "windows-sys",
 ]
 
 [[package]]
 name = "autocfg"
-version = "1.5.0"
+version = "1.4.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "c08606f8c3cbf4ce6ec8e28fb0014a2c086708fe954eaa885384a6165172e7e8"
+checksum = "ace50bade8e6234aa140d9a2f552bbee1db4d353f69b8217bc503490fc1a9f26"
 
 [[package]]
 name = "bitflags"
-version = "2.11.1"
+version = "1.3.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "c4512299f36f043ab09a583e57bceb5a5aab7a73db1805848e8fef3c9e8c78b3"
+checksum = "bef38d45163c2f1dde094a7dfd33ccf595c92905c8f8f4fdc18d06fb1037718a"
+
+[[package]]
+name = "bitflags"
+version = "2.9.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "5c8214115b7bf84099f1309324e63141d4c5d7cc26862f97a0a857dbefe165bd"
 
 [[package]]
 name = "bitvec"
@@ -84,15 +90,15 @@ dependencies = [
 
 [[package]]
 name = "bumpalo"
-version = "3.20.2"
+version = "3.17.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "5d20789868f4b01b2f2caec9f5c4e0213b41e3e5702a50157d699ae31ced2fcb"
+checksum = "1628fb46dfa0b37568d12e5edd512553eccf6a22a78e8bde00bb4aed84d5bdbf"
 
 [[package]]
 name = "bytemuck"
-version = "1.25.0"
+version = "1.22.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "c8efb64bd706a16a1bdde310ae86b351e4d21550d98d056f22f8a7f7a2183fec"
+checksum = "b6b1fc10dbac614ebc03540c9dbd60e83887fda27794998c6528f1782047d540"
 
 [[package]]
 name = "byteorder-lite"
@@ -102,34 +108,33 @@ checksum = "8f1fe948ff07f4bd06c30984e69f5b4899c516a3ef74f34df92a2df2ab535495"
 
 [[package]]
 name = "cc"
-version = "1.2.60"
+version = "1.2.19"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "43c5703da9466b66a946814e1adf53ea2c90f10063b86290cc9eb67ce3478a20"
+checksum = "8e3a13707ac958681c13b39b458c073d0d9bc8a22cb1b2f4c8e55eb72c13f362"
 dependencies = [
- "find-msvc-tools",
  "shlex",
 ]
 
 [[package]]
 name = "cfg-if"
-version = "1.0.4"
+version = "1.0.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "9330f8b2ff13f34540b44e946ef35111825727b38d33286ef986142615121801"
+checksum = "baf1de4339761588bc0619e3cbc0120ee582ebb74b53b4efbf79117bd2da40fd"
 
 [[package]]
 name = "clap"
-version = "4.6.1"
+version = "4.5.36"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "1ddb117e43bbf7dacf0a4190fef4d345b9bad68dfc649cb349e7d17d28428e51"
+checksum = "2df961d8c8a0d08aa9945718ccf584145eee3f3aa06cddbeac12933781102e04"
 dependencies = [
  "clap_builder",
 ]
 
 [[package]]
 name = "clap_builder"
-version = "4.6.0"
+version = "4.5.36"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "714a53001bf66416adb0e2ef5ac857140e7dc3a0c48fb28b2f10762fc4b5069f"
+checksum = "132dbda40fb6753878316a489d5a1242a8ef2f0d9e47ba01c951ea8aa7d013a5"
 dependencies = [
  "anstream",
  "anstyle",
@@ -140,25 +145,34 @@ dependencies = [
 
 [[package]]
 name = "clap_lex"
-version = "1.1.0"
+version = "0.7.4"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "c8d4a3bb8b1e0c1050499d1815f5ab16d04f0959b233085fb31653fbfc9d98f9"
+checksum = "f46ad14479a25103f283c0f10005961cf086d8dc42205bb44c46ac563475dca6"
 
 [[package]]
 name = "colorchoice"
-version = "1.0.5"
+version = "1.0.3"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "1d07550c9036bf2ae0c684c4297d503f838287c83c53686d05370d0e139ae570"
+checksum = "5b63caa9aa9397e2d9480a9b13673856c78d8ac123288526c37d7839f2a86990"
 
 [[package]]
 name = "crc32fast"
-version = "1.5.0"
+version = "1.4.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "9481c1c90cbf2ac953f07c8d4a58aa3945c425b7185c9154d67a65e4230da511"
+checksum = "a97769d94ddab943e4510d138150169a2758b5ef3eb191a9ee688de3e23ef7b3"
 dependencies = [
  "cfg-if",
 ]
 
+[[package]]
+name = "crossbeam-channel"
+version = "0.5.15"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "82b8f8f868b36967f9606790d1903570de9ceaf870a7bf9fbbd3016d636a2cb2"
+dependencies = [
+ "crossbeam-utils",
+]
+
 [[package]]
 name = "crossbeam-deque"
 version = "0.8.6"
@@ -192,18 +206,18 @@ checksum = "48c757948c5ede0e46177b7add2e67155f70e33c07fea8284df6576da70b3719"
 
 [[package]]
 name = "env_filter"
-version = "1.0.1"
+version = "0.1.3"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "32e90c2accc4b07a8456ea0debdc2e7587bdd890680d71173a15d4ae604f6eef"
+checksum = "186e05a59d4c50738528153b83b0b0194d3a29507dfec16eccd4b342903397d0"
 dependencies = [
  "log",
 ]
 
 [[package]]
 name = "env_logger"
-version = "0.11.10"
+version = "0.11.8"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "0621c04f2196ac3f488dd583365b9c09be011a4ab8b9f37248ffcc8f6198b56a"
+checksum = "13c863f0904021b108aa8b2f55046443e6b1ebde8fd4a15c399893aae4fa069f"
 dependencies = [
  "anstream",
  "anstyle",
@@ -219,9 +233,9 @@ checksum = "877a4ace8713b0bcf2a4e7eec82529c029f1d0619886d18145fea96c3ffe5c0f"
 
 [[package]]
 name = "errno"
-version = "0.3.14"
+version = "0.3.11"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "39cab71617ae0d63f51a36d69f866391735b51691dbda63cf6f96d042b63efeb"
+checksum = "976dd42dc7e85965fe702eb8164f21f450704bdde31faefd6471dba214cb594e"
 dependencies = [
  "libc",
  "windows-sys",
@@ -237,16 +251,22 @@ dependencies = [
 ]
 
 [[package]]
-name = "find-msvc-tools"
-version = "0.1.9"
+name = "filetime"
+version = "0.2.25"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "5baebc0774151f905a1a2cc41989300b1e6fbb29aff0ceffa1064fdd3088d582"
+checksum = "35c0522e981e68cbfa8c3f978441a5f34b30b96e146b33cd3359176b50fe8586"
+dependencies = [
+ "cfg-if",
+ "libc",
+ "libredox",
+ "windows-sys",
+]
 
 [[package]]
 name = "flate2"
-version = "1.1.9"
+version = "1.1.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "843fba2746e448b37e26a819579957415c8cef339bf08564fe8b7ddbd959573c"
+checksum = "7ced92e76e966ca2fd84c8f7aa01a4aea65b0eb6648d72f7c8f3e2764a67fece"
 dependencies = [
  "crc32fast",
  "miniz_oxide",
@@ -260,34 +280,33 @@ checksum = "e6d5a32815ae3f33302d95fdcb2ce17862f8c65363dcfd29360480ba1001fc9c"
 
 [[package]]
 name = "glob"
-version = "0.3.3"
+version = "0.3.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "0cc23270f6e1808e30a928bdc84dea0b9b4136a8bc82338574f23baf47bbd280"
+checksum = "a8d1add55171497b4705a648c6b583acafb01d58050a51727785f0b2c8e0a2b2"
 
 [[package]]
 name = "hashbrown"
-version = "0.17.0"
+version = "0.15.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "4f467dd6dccf739c208452f8014c75c18bb8301b050ad1cfb27153803edb0f51"
+checksum = "bf151400ff0baff5465007dd2f3e717f3fe502074ca563069ce3a6629d07b289"
 
 [[package]]
 name = "image"
-version = "0.25.9"
+version = "0.25.6"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "e6506c6c10786659413faa717ceebcb8f70731c0a60cbae39795fdf114519c1a"
+checksum = "db35664ce6b9810857a38a906215e75a9c879f0696556a39f59c62829710251a"
 dependencies = [
  "bytemuck",
  "byteorder-lite",
- "moxcms",
  "num-traits",
  "png",
 ]
 
 [[package]]
 name = "indexmap"
-version = "2.14.0"
+version = "2.9.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "d466e9454f08e4a911e14806c24e16fba1b4c121d1ea474396f396069cf949d9"
+checksum = "cea70ddb795996207ad57735b50c5982d8844f38ba9ee5f1aedcfb708a2aa11e"
 dependencies = [
  "equivalent",
  "hashbrown",
@@ -296,27 +315,21 @@ dependencies = [
 
 [[package]]
 name = "is_terminal_polyfill"
-version = "1.70.2"
+version = "1.70.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "a6cb138bb79a146c1bd460005623e142ef0181e3d0219cb493e02f7d08a35695"
-
-[[package]]
-name = "itoa"
-version = "1.0.18"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "8f42a60cbdf9a97f5d2305f08a87dc4e09308d1276d28c869c684d7777685682"
+checksum = "7943c866cc5cd64cbc25b2e01621d07fa8eb2a1a23160ee81ce38704e97b8ecf"
 
 [[package]]
 name = "libc"
-version = "0.2.185"
+version = "0.2.172"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "52ff2c0fe9bc6cb6b14a0592c2ff4fa9ceb83eea9db979b0487cd054946a2b8f"
+checksum = "d750af042f7ef4f724306de029d18836c26c1765a54a6a3f094cbd23a7267ffa"
 
 [[package]]
 name = "libdeflate-sys"
-version = "1.25.2"
+version = "1.23.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "72753e0008ea87963d2f0770042d0df7abe51fafbb8dcaf618ac440f2f1fec0a"
+checksum = "38b72ad3fbf5ac78f2df7b36075e48adf2459b57c150b9e63937d0204d0f9cd7"
 dependencies = [
  "cc",
  "pkg-config",
@@ -324,49 +337,44 @@ dependencies = [
 
 [[package]]
 name = "libdeflater"
-version = "1.25.2"
+version = "1.23.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "d1ee41cf6fb1bb6030dfb59ffb7bc01ab26aade44142084c87f0fc7a1658fe71"
+checksum = "013344b17f9dceddff4872559ae19378bd8ee0479eccdd266d2dd2e894b4792f"
 dependencies = [
  "libdeflate-sys",
 ]
 
 [[package]]
-name = "linux-raw-sys"
-version = "0.12.1"
+name = "libredox"
+version = "0.1.3"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "32a66949e030da00e8c7d4434b251670a91556f4144941d37452769c25d58a53"
-
-[[package]]
-name = "log"
-version = "0.4.30"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "616ec5685824bcc94416c6d4a7a446eea774a31efd7062c8480ba6fd06d7a6e5"
-
-[[package]]
-name = "memchr"
-version = "2.8.0"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "f8ca58f447f06ed17d5fc4043ce1b10dd205e060fb3ce5b979b8ed8e59ff3f79"
-
-[[package]]
-name = "miniz_oxide"
-version = "0.8.9"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "1fa76a2c86f704bdb222d66965fb3d63269ce38518b83cb0575fca855ebb6316"
+checksum = "c0ff37bd590ca25063e35af745c343cb7a0271906fb7b37e4813e8f79f00268d"
 dependencies = [
- "adler2",
- "simd-adler32",
+ "bitflags 2.9.0",
+ "libc",
+ "redox_syscall",
 ]
 
 [[package]]
-name = "moxcms"
-version = "0.7.11"
+name = "linux-raw-sys"
+version = "0.9.4"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "ac9557c559cd6fc9867e122e20d2cbefc9ca29d80d027a8e39310920ed2f0a97"
+checksum = "cd945864f07fe9f5371a27ad7b52a172b4b499999f1d97574c9fa68373937e12"
+
+[[package]]
+name = "log"
+version = "0.4.27"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "13dc2df351e3202783a1fe0d44375f7295ffb4049267b0f3018346dc122a1d94"
+
+[[package]]
+name = "miniz_oxide"
+version = "0.8.8"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "3be647b768db090acb35d5ec5db2b0e1f1de11133ca123b9eacf5137868f892a"
 dependencies = [
- "num-traits",
- "pxfm",
+ "adler2",
+ "simd-adler32",
 ]
 
 [[package]]
@@ -379,80 +387,50 @@ dependencies = [
 ]
 
 [[package]]
-name = "once_cell_polyfill"
-version = "1.70.2"
+name = "once_cell"
+version = "1.21.3"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "384b8ab6d37215f3c5301a95a4accb5d64aa607f1fcb26a11b5303878451b4fe"
+checksum = "42f5e15c9953c5e4ccceeb2e7382a716482c34515315f7b03532b8b4e8393d2d"
 
 [[package]]
 name = "oxipng"
-version = "10.1.1"
+version = "9.1.5"
 dependencies = [
  "bitvec",
  "clap",
+ "crossbeam-channel",
  "env_logger",
+ "filetime",
  "glob",
  "image",
  "indexmap",
  "libdeflater",
  "log",
- "parse-size",
  "rayon",
  "rgb",
  "rustc-hash",
- "serde_json",
  "zopfli",
 ]
 
-[[package]]
-name = "parse-size"
-version = "1.1.0"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "487f2ccd1e17ce8c1bfab3a65c89525af41cfad4c8659021a1e9a2aacd73b89b"
-
 [[package]]
 name = "pkg-config"
-version = "0.3.33"
+version = "0.3.32"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "19f132c84eca552bf34cab8ec81f1c1dcc229b811638f9d283dceabe58c5569e"
+checksum = "7edddbd0b52d732b21ad9a5fab5c704c14cd949e5e9a1ec5929a24fded1b904c"
 
 [[package]]
 name = "png"
-version = "0.18.1"
+version = "0.17.16"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "60769b8b31b2a9f263dae2776c37b1b28ae246943cf719eb6946a1db05128a61"
+checksum = "82151a2fc869e011c153adc57cf2789ccb8d9906ce52c0b39a6b5697749d7526"
 dependencies = [
- "bitflags",
+ "bitflags 1.3.2",
  "crc32fast",
  "fdeflate",
  "flate2",
  "miniz_oxide",
 ]
 
-[[package]]
-name = "proc-macro2"
-version = "1.0.106"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "8fd00f0bb2e90d81d1044c2b32617f68fcb9fa3bb7640c23e9c748e53fb30934"
-dependencies = [
- "unicode-ident",
-]
-
-[[package]]
-name = "pxfm"
-version = "0.1.29"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "e0c5ccf5294c6ccd63a74f1565028353830a9c2f5eb0c682c355c471726a6e3f"
-
-[[package]]
-name = "quote"
-version = "1.0.45"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "41f2619966050689382d2b44f664f4bc593e129785a36d6ee376ddf37259b924"
-dependencies = [
- "proc-macro2",
-]
-
 [[package]]
 name = "radium"
 version = "0.7.0"
@@ -461,9 +439,9 @@ checksum = "dc33ff2d4973d518d823d61aa239014831e521c75da58e3df4840d3f47749d09"
 
 [[package]]
 name = "rayon"
-version = "1.12.0"
+version = "1.10.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "fb39b166781f92d482534ef4b4b1b2568f42613b53e5b6c160e24cfbfa30926d"
+checksum = "b418a60154510ca1a002a752ca9714984e21e4241e804d32555251faf8b78ffa"
 dependencies = [
  "either",
  "rayon-core",
@@ -471,84 +449,51 @@ dependencies = [
 
 [[package]]
 name = "rayon-core"
-version = "1.13.0"
+version = "1.12.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "22e18b0f0062d30d4230b2e85ff77fdfe4326feb054b9783a3460d8435c8ab91"
+checksum = "1465873a3dfdaa8ae7cb14b4383657caab0b3e8a0aa9ae8e04b044854c8dfce2"
 dependencies = [
  "crossbeam-deque",
  "crossbeam-utils",
 ]
 
 [[package]]
-name = "rgb"
-version = "0.8.53"
+name = "redox_syscall"
+version = "0.5.11"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "47b34b781b31e5d73e9fbc8689c70551fd1ade9a19e3e28cfec8580a79290cc4"
+checksum = "d2f103c6d277498fbceb16e84d317e2a400f160f46904d5f5410848c829511a3"
+dependencies = [
+ "bitflags 2.9.0",
+]
+
+[[package]]
+name = "rgb"
+version = "0.8.50"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "57397d16646700483b67d2dd6511d79318f9d057fdbd21a4066aeac8b41d310a"
 dependencies = [
  "bytemuck",
 ]
 
 [[package]]
 name = "rustc-hash"
-version = "2.1.2"
+version = "2.1.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "94300abf3f1ae2e2b8ffb7b58043de3d399c73fa6f4b73826402a5c457614dbe"
+checksum = "357703d41365b4b27c590e3ed91eabb1b663f07c4c084095e60cbed4362dff0d"
 
 [[package]]
 name = "rustix"
-version = "1.1.4"
+version = "1.0.5"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "b6fe4565b9518b83ef4f91bb47ce29620ca828bd32cb7e408f0062e9930ba190"
+checksum = "d97817398dd4bb2e6da002002db259209759911da105da92bec29ccb12cf58bf"
 dependencies = [
- "bitflags",
+ "bitflags 2.9.0",
  "errno",
  "libc",
  "linux-raw-sys",
  "windows-sys",
 ]
 
-[[package]]
-name = "serde"
-version = "1.0.228"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "9a8e94ea7f378bd32cbbd37198a4a91436180c5bb472411e48b5ec2e2124ae9e"
-dependencies = [
- "serde_core",
-]
-
-[[package]]
-name = "serde_core"
-version = "1.0.228"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "41d385c7d4ca58e59fc732af25c3983b67ac852c1a25000afe1175de458b67ad"
-dependencies = [
- "serde_derive",
-]
-
-[[package]]
-name = "serde_derive"
-version = "1.0.228"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "d540f220d3187173da220f885ab66608367b6574e925011a9353e4badda91d79"
-dependencies = [
- "proc-macro2",
- "quote",
- "syn",
-]
-
-[[package]]
-name = "serde_json"
-version = "1.0.150"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "e8014e44b4736ed0538adeecded0fce2a272f22dc9578a7eb6b2d9993c74cfb9"
-dependencies = [
- "itoa",
- "memchr",
- "serde",
- "serde_core",
- "zmij",
-]
-
 [[package]]
 name = "shlex"
 version = "1.3.0"
@@ -557,9 +502,9 @@ checksum = "0fda2ff0d084019ba4d7c6f371c95d8fd75ce3524c3cb8fb653a3023f6323e64"
 
 [[package]]
 name = "simd-adler32"
-version = "0.3.9"
+version = "0.3.7"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "703d5c7ef118737c72f1af64ad2f6f8c5e1921f818cdcb97b8fe6fc69bf66214"
+checksum = "d66dc143e6b11c1eddc06d5c423cfc97062865baf299914ab64caa38182078fe"
 
 [[package]]
 name = "strsim"
@@ -567,17 +512,6 @@ version = "0.11.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "7da8b5736845d9f2fcb837ea5d9e2628564b3b043a70948a3f0b778838c5fb4f"
 
-[[package]]
-name = "syn"
-version = "2.0.117"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "e665b8803e7b1d2a727f4023456bbbbe74da67099c585258af0ad9c5013b9b99"
-dependencies = [
- "proc-macro2",
- "quote",
- "unicode-ident",
-]
-
 [[package]]
 name = "tap"
 version = "1.0.1"
@@ -586,20 +520,14 @@ checksum = "55937e1799185b12863d447f42597ed69d9928686b8d88a1df17376a097d8369"
 
 [[package]]
 name = "terminal_size"
-version = "0.4.4"
+version = "0.4.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "230a1b821ccbd75b185820a1f1ff7b14d21da1e442e22c0863ea5f08771a8874"
+checksum = "45c6481c4829e4cc63825e62c49186a34538b7b2750b73b266581ffb612fb5ed"
 dependencies = [
  "rustix",
  "windows-sys",
 ]
 
-[[package]]
-name = "unicode-ident"
-version = "1.0.24"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "e6e4313cd5fcd3dad5cafa179702e2b244f760991f45397d14d4ebf38247da75"
-
 [[package]]
 name = "utf8parse"
 version = "0.2.2"
@@ -607,20 +535,78 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "06abde3611657adf66d383f00b093d7faecc7fa57071cce2578660c9f1010821"
 
 [[package]]
-name = "windows-link"
-version = "0.2.1"
+name = "windows-sys"
+version = "0.59.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "f0805222e57f7521d6a62e36fa9163bc891acd422f971defe97d64e70d0a4fe5"
+checksum = "1e38bc4d79ed67fd075bcc251a1c39b32a1776bbe92e5bef1f0bf1f8c531853b"
+dependencies = [
+ "windows-targets",
+]
 
 [[package]]
-name = "windows-sys"
-version = "0.61.2"
+name = "windows-targets"
+version = "0.52.6"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "ae137229bcbd6cdf0f7b80a31df61766145077ddf49416a728b02cb3921ff3fc"
+checksum = "9b724f72796e036ab90c1021d4780d4d3d648aca59e491e6b98e725b84e99973"
 dependencies = [
- "windows-link",
+ "windows_aarch64_gnullvm",
+ "windows_aarch64_msvc",
+ "windows_i686_gnu",
+ "windows_i686_gnullvm",
+ "windows_i686_msvc",
+ "windows_x86_64_gnu",
+ "windows_x86_64_gnullvm",
+ "windows_x86_64_msvc",
 ]
 
+[[package]]
+name = "windows_aarch64_gnullvm"
+version = "0.52.6"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "32a4622180e7a0ec044bb555404c800bc9fd9ec262ec147edd5989ccd0c02cd3"
+
+[[package]]
+name = "windows_aarch64_msvc"
+version = "0.52.6"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "09ec2a7bb152e2252b53fa7803150007879548bc709c039df7627cabbd05d469"
+
+[[package]]
+name = "windows_i686_gnu"
+version = "0.52.6"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "8e9b5ad5ab802e97eb8e295ac6720e509ee4c243f69d781394014ebfe8bbfa0b"
+
+[[package]]
+name = "windows_i686_gnullvm"
+version = "0.52.6"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "0eee52d38c090b3caa76c563b86c3a4bd71ef1a819287c19d586d7334ae8ed66"
+
+[[package]]
+name = "windows_i686_msvc"
+version = "0.52.6"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "240948bc05c5e7c6dabba28bf89d89ffce3e303022809e73deaefe4f6ec56c66"
+
+[[package]]
+name = "windows_x86_64_gnu"
+version = "0.52.6"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "147a5c80aabfbf0c7d901cb5895d1de30ef2907eb21fbbab29ca94c5b08b1a78"
+
+[[package]]
+name = "windows_x86_64_gnullvm"
+version = "0.52.6"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "24d5b23dc417412679681396f2b49f3de8c1473deb516bd34410872eff51ed0d"
+
+[[package]]
+name = "windows_x86_64_msvc"
+version = "0.52.6"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "589f6da84c646204747d1270a2a5661ea66ed1cced2631d546fdfb155959f9ec"
+
 [[package]]
 name = "wyz"
 version = "0.5.1"
@@ -630,17 +616,11 @@ dependencies = [
  "tap",
 ]
 
-[[package]]
-name = "zmij"
-version = "1.0.21"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "b8848ee67ecc8aedbaf3e4122217aff892639231befc6a1b58d29fff4c2cabaa"
-
 [[package]]
 name = "zopfli"
-version = "0.8.3"
+version = "0.8.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "f05cd8797d63865425ff89b5c4a48804f35ba0ce8d125800027ad6017d2b5249"
+checksum = "edfc5ee405f504cd4984ecc6f14d02d55cfda60fa4b689434ef4102aae150cd7"
 dependencies = [
  "bumpalo",
  "crc32fast",

Cargo.toml

@@ -4,7 +4,7 @@ categories = ["command-line-utilities", "compression"]
 description = "A lossless PNG compression optimizer"
 keywords = ["png", "image-compression", "optimization", "multi-threading", "lossless"]
 documentation = "https://docs.rs/oxipng"
-edition = "2024"
+edition = "2021"
 exclude = [
   ".editorconfig",
   ".gitattributes",
@@ -16,15 +16,15 @@ exclude = [
   "tests/*",
   "xtask/*",
 ]
-homepage = "https://github.com/oxipng/oxipng"
+homepage = "https://github.com/shssoichiro/oxipng"
 license = "MIT"
 name = "oxipng"
-repository = "https://github.com/oxipng/oxipng"
-version = "10.1.1"
-rust-version = "1.85.1"
+repository = "https://github.com/shssoichiro/oxipng"
+version = "9.1.5"
+rust-version = "1.74.0"
 
 [badges]
-travis-ci = { repository = "oxipng/oxipng", branch = "master" }
+travis-ci = { repository = "shssoichiro/oxipng", branch = "master" }
 maintenance = { status = "actively-developed" }
 
 [[bin]]
@@ -38,32 +38,55 @@ name = "zopfli"
 required-features = ["zopfli"]
 
 [dependencies]
+zopfli = { version = "0.8.2", optional = true, default-features = false, features = ["std", "zlib"] }
+rgb = "0.8.50"
+indexmap = "2.9.0"
+libdeflater = "1.23.1"
+log = "0.4.27"
 bitvec = "1.0.1"
-clap = { version = "4.6.0", optional = true, features = ["wrap_help"] }
-env_logger = { version = "0.11.10", optional = true, default-features = false, features = ["auto-color"] }
-image = { version = "0.25.9", optional = true, default-features = false, features = ["png"] }
-indexmap = "2.14.0"
-libdeflater = "1.25.2"
-log = "0.4.30"
-parse-size = { version = "1.1.0", optional = true }
-rayon = { version = "1.11.0", optional = true }
-rgb = "0.8.53"
-rustc-hash = "2.1.2"
-zopfli = { version = "0.8.3", optional = true, default-features = false, features = ["std", "zlib"] }
+rustc-hash = "2.1.1"
 
-[target.'cfg(windows)'.dependencies]
-glob = { version = "0.3.3", optional = true }
+[dependencies.env_logger]
+optional = true
+default-features = false
+features = ["auto-color"]
+version = "0.11.8"
 
-[dev-dependencies]
-serde_json = "1.0.150"
+[dependencies.crossbeam-channel]
+optional = true
+version = "0.5.15"
+
+[dependencies.filetime]
+optional = true
+version = "0.2.25"
+
+[dependencies.rayon]
+optional = true
+version = "1.10.0"
+
+[dependencies.clap]
+optional = true
+version = "4.5.36"
+features = ["wrap_help"]
+
+[target.'cfg(windows)'.dependencies.glob]
+optional = true
+version = "0.3.2"
+
+[dependencies.image]
+optional = true
+default-features = false
+features = ["png"]
+version = "0.25.6"
 
 [features]
-binary = ["dep:clap", "dep:glob", "dep:env_logger", "dep:parse-size"]
-default = ["binary", "parallel", "zopfli"]
-parallel = ["dep:rayon", "indexmap/rayon"]
+binary = ["dep:clap", "dep:glob", "dep:env_logger"]
+default = ["binary", "parallel", "zopfli", "filetime"]
+parallel = ["dep:rayon", "indexmap/rayon", "dep:crossbeam-channel"]
 freestanding = ["libdeflater/freestanding"]
 sanity-checks = ["dep:image"]
 zopfli = ["dep:zopfli"]
+filetime = ["dep:filetime"]
 system-libdeflate = ["libdeflater/dynamic"]
 
 [lib]
@@ -85,37 +108,3 @@ assets = [
     ["README.md", "usr/share/doc/oxipng/", "644"],
     ["CHANGELOG.md", "usr/share/doc/oxipng/", "644"],
 ]
-
-[lints.rust]
-missing_copy_implementations = "deny"
-missing_debug_implementations = "deny"
-trivial_casts = "warn"
-trivial_numeric_casts = "warn"
-unused_import_braces = "warn"
-
-[lints.clippy]
-cloned_instead_of_copied = "warn"
-expl_impl_clone_on_copy = "warn"
-float_cmp_const = "warn"
-if_not_else = "warn"
-ignored_unit_patterns = "warn"
-linkedlist = "warn"
-manual_let_else = "warn"
-map_flatten = "warn"
-map_unwrap_or = "warn"
-match_same_arms = "warn"
-mem_forget = "warn"
-missing_const_for_fn = "warn"
-mut_mut = "warn"
-mutex_integer = "warn"
-needless_continue = "warn"
-option_if_let_else = "warn"
-path_buf_push_overwrite = "warn"
-range_plus_one = "warn"
-redundant_clone = "warn"
-redundant_closure_for_method_calls = "warn"
-semicolon_if_nothing_returned = "warn"
-unnecessary_semicolon = "warn"
-unseparated_literal_suffix = "warn"
-use_self = "warn"
-useless_let_if_seq = "warn"

Dockerfile

@@ -2,7 +2,7 @@
 # check=error=true
 FROM --platform=$BUILDPLATFORM tonistiigi/xx AS xx
 
-FROM --platform=$BUILDPLATFORM rust:1.85.1-alpine AS base
+FROM --platform=$BUILDPLATFORM rust:1.74-alpine AS base
 
 RUN apk update && \
     apk add \
@@ -37,7 +37,7 @@ LABEL org.opencontainers.image.title="Oxipng"
 LABEL org.opencontainers.image.description="Multithreaded PNG optimizer written in Rust"
 LABEL org.opencontainers.image.authors="Joshua Holmer <jholmer.in@gmail.com>"
 LABEL org.opencontainers.image.licenses="MIT"
-LABEL org.opencontainers.image.source="https://github.com/oxipng/oxipng"
+LABEL org.opencontainers.image.source="https://github.com/shssoichiro/oxipng"
 
 COPY --from=base /src/target/oxipng /usr/local/bin/oxipng
 

MANUAL.txt

@@ -1,4 +1,4 @@
-oxipng 10.1.0
+oxipng 9.1.5
 Losslessly improve compression of PNG files
 
 Usage: oxipng [OPTIONS] <files>...
@@ -13,14 +13,14 @@ Options:
           compression. Lower levels are faster, higher levels provide better compression, though
           with increasingly diminishing returns.
           
-              0   => --zc 5  --fast              (filter chosen heuristically)
-              1   => --zc 10 --fast              (filter chosen heuristically)
-              2   => --zc 11 -f 0,1,6,7 --fast
-              3   => --zc 11 -f 0,7,8,9         --brute-level 1 --brute-lines 3
-              4   => --zc 12 -f 0,7,8,9         --brute-level 1 --brute-lines 4
-              5   => --zc 12 -f 0,1,2,5,6,7,8,9 --brute-level 4 --brute-lines 4
-              6   => --zc 12 -f 0-9             --brute-level 5 --brute-lines 8
-              max => (stable alias for the maximum level)
+              0   => --zc 5 --fast               (1 trial, determined heuristically)
+              1   => --zc 10 --fast              (1 trial, determined heuristically)
+              2   => --zc 11 -f 0,1,6,7 --fast   (4 fast trials, 1 main trial)
+              3   => --zc 11 -f 0,7,8,9          (4 trials)
+              4   => --zc 12 -f 0,7,8,9          (4 trials)
+              5   => --zc 12 -f 0,1,2,5,6,7,8,9  (8 trials)
+              6   => --zc 12 -f 0-9              (10 trials)
+              max =>                             (stable alias for the max level)
           
           Manually specifying a compression option (zc, f, etc.) will override the optimization
           preset, regardless of the order you write the arguments.
@@ -45,7 +45,7 @@ Options:
   -p, --preserve
           Preserve file permissions and timestamps if possible
 
-  -d, --dry-run
+  -P, --pretend
           Do not write any files, only show compression results
 
   -s
@@ -61,14 +61,10 @@ Options:
           
           CAUTION: 'all' will convert APNGs to standard PNGs.
           
-          Please note that regardless of any options set, some chunks will necessarily be stripped
-          when invalidated by the optimization:
-              bKGD, sBIT, hIST: Stripped if the color type or bit depth changes.
-              iDOT: Always stripped.
-              caBX: Stripped if it contains C2PA metadata. If explicitly retained by `--keep`,
-              optimization will be aborted.
+          Note that 'bKGD', 'sBIT' and 'hIST' will be forcibly stripped if the color type or bit
+          depth is changed, regardless of any options set.
           
-          The default when --strip is not passed is to keep all chunks that remain valid.
+          The default when --strip is not passed is to keep all metadata.
 
       --keep <list>
           Strip all metadata chunks except those in the comma-separated list. The special value
@@ -83,17 +79,17 @@ Options:
           but take care as while this is “visually lossless”, it is technically a lossy
           transformation and may be unsuitable for some applications.
 
-  -i, --interlace <mode>
-          Set the PNG interlacing mode, where <mode> is one of:
+  -i, --interlace <type>
+          Set the PNG interlacing type, where <type> is one of:
           
-              off   =>  Remove interlacing from all images that are processed
-              on    =>  Apply Adam7 interlacing on all images that are processed
-              keep  =>  Keep the existing interlacing mode of each image
+              0     =>  Remove interlacing from all images that are processed
+              1     =>  Apply Adam7 interlacing on all images that are processed
+              keep  =>  Keep the existing interlacing type of each image
           
           Note that interlacing can add 25-50% to the size of an optimized image. Only use it if you
           believe the benefits outweigh the costs for your use case.
           
-          [default: off]
+          [default: 0]
 
       --scale16
           Forcibly reduce images with 16 bits per channel to 8 bits per channel. This is a lossy
@@ -105,13 +101,10 @@ Options:
           losslessly.
 
   -v, --verbose...
-          Show per-file info (use multiple times for more detail)
+          Run in verbose mode (use twice to increase verbosity)
 
   -q, --quiet
-          Suppress all output messages
-
-  -j, --json
-          Print results as JSON
+          Run in quiet mode
 
   -f, --filters <list>
           Perform compression trials with each of the given filter types. You can specify a
@@ -126,9 +119,9 @@ Options:
           
           Heuristic strategies (try to find the best delta filter for each line)
               5  =>  MinSum    Minimum sum of absolute differences
-              6  =>  Entropy   Smallest Shannon entropy
+              6  =>  Entropy   Highest Shannon entropy
               7  =>  Bigrams   Lowest count of distinct bigrams
-              8  =>  BigEnt    Smallest Shannon entropy of bigrams
+              8  =>  BigEnt    Highest Shannon entropy of bigrams
               9  =>  Brute     Smallest compressed size (slow)
           
           The default value depends on the optimization level preset.
@@ -166,12 +159,12 @@ Options:
 
       --fix
           Do not perform checksum validation of PNG chunks. This may allow some files with errors to
-          be processed successfully. The output will always have correct checksums.
+          be processed successfully.
 
       --force
           Write the output even if it is larger than the input
 
-  -z, --zopfli
+  -Z, --zopfli
           Use the much slower but stronger Zopfli compressor for main compression trials.
           Recommended use is with '-o max' and '--fast'.
 
@@ -181,18 +174,6 @@ Options:
           
           [default: 15]
 
-      --ziwi <iterations>
-          Stop Zopfli compression after this number of iterations without improvement. Use this in
-          conjunction with a high value for '--zi' to achieve better compression in reasonable time.
-
-      --brute-level <level>
-          Set the libdeflate compression level to use with the Brute filter strategy. Sane values
-          are 1-5. Higher values are not necessarily better.
-
-      --brute-lines <lines>
-          Set the number of lines to compress at once with the Brute filter strategy. Sane values
-          are 2-16. Higher values are not necessarily better.
-
       --timeout <secs>
           Maximum amount of time, in seconds, to spend on optimizations. Oxipng will check the
           timeout before each transformation or compression trial, and will stop trying to optimize
@@ -200,15 +181,6 @@ Options:
           are already in progress, so it is currently of limited effectiveness for large files with
           high compression levels.
 
-      --max-raw-size <bytes>
-          Maximum size to allow for the input image. If the raw, decompressed image data (or the
-          file size) of the image exceeds this size, it will be skipped. This is useful for limiting
-          memory usage or avoiding long processing times on large images. The value may be specified
-          with a unit suffix such as k, KB, m, MB, etc.
-          
-          The decompressed size of an image is roughly equal to width * height * bit-depth / 8. E.g.
-          a 1920x1080 image with 24-bit color depth would be roughly 6MB.
-
   -t, --threads <num>
           Set the maximum number of threads to use. Oxipng uses multithreading to evaluate multiple
           optimizations on the same file in parallel as well as process multiple files in parallel.

README.md

@@ -1,19 +1,19 @@
 # Oxipng
 
-[![Build Status](https://github.com/oxipng/oxipng/workflows/oxipng/badge.svg)](https://github.com/oxipng/oxipng/actions?query=branch%3Amaster)
+[![Build Status](https://github.com/shssoichiro/oxipng/workflows/oxipng/badge.svg)](https://github.com/shssoichiro/oxipng/actions?query=branch%3Amaster)
 [![Version](https://img.shields.io/crates/v/oxipng.svg)](https://crates.io/crates/oxipng)
-[![License](https://img.shields.io/crates/l/oxipng.svg)](https://github.com/oxipng/oxipng/blob/master/LICENSE)
+[![License](https://img.shields.io/crates/l/oxipng.svg)](https://github.com/shssoichiro/oxipng/blob/master/LICENSE)
 [![Docs](https://docs.rs/oxipng/badge.svg)](https://docs.rs/oxipng)
 
 ## Overview
 
 Oxipng is a multithreaded lossless PNG/APNG compression optimizer. It can be used via a command-line
-interface or as a library in other Rust programs. It is fast and highly effective.
+interface or as a library in other Rust programs.
 
 ## Installing
 
 Oxipng for Windows can be downloaded via the
-[Releases](https://github.com/oxipng/oxipng/releases) section on its GitHub page. Recently,
+[Releases](https://github.com/shssoichiro/oxipng/releases) section on its GitHub page. Recently,
 however, Oxipng has also been made available through package managers. Check the list below for
 up-to-date options.
 
@@ -34,13 +34,13 @@ Oxipng can also be built from source using the latest stable or nightly Rust.
 This is primarily useful for developing on Oxipng.
 
 ```
-git clone https://github.com/oxipng/oxipng.git
+git clone https://github.com/shssoichiro/oxipng.git
 cd oxipng
 cargo build --release
 cp target/release/oxipng /usr/local/bin
 ```
 
-The current minimum supported Rust version is **1.85.1**.
+The current minimum supported Rust version is **1.74.0**.
 
 Oxipng follows Semantic Versioning.
 
@@ -76,14 +76,7 @@ All options are case-sensitive.
 \* Note that oxipng is not a brute-force optimizer. This means that while higher optimization levels
 are almost always better or equal to lower levels, this is not guaranteed and it is possible in
 rare circumstances that a lower level may give a marginally smaller output. Similarly, using Zopfli
-compression (`-z`) is not guaranteed to always be better than default compression.
-
-## APNG support
-
-Oxipng currently only supports limited optimization of animated PNGs (APNGs). It can perform
-alpha-optimization, refiltering and recompression of all frames, but all transformations will be
-disabled. For best results, it is recommended to use another tool such as
-[apngopt](https://sourceforge.net/projects/apng/files/APNG_Optimizer/) before running Oxipng.
+compression (`-Z`) is not guaranteed to always be better than without.
 
 ## Git integration via [pre-commit]
 
@@ -92,8 +85,8 @@ preamble to an already existing one:
 
 ```yaml
 repos:
-  - repo: https://github.com/oxipng/oxipng
-    rev: v10.0.0
+  - repo: https://github.com/shssoichiro/oxipng
+    rev: v9.1.4
     hooks:
       - id: oxipng
         args: ["-o", "4", "--strip", "safe", "--alpha"]
@@ -102,16 +95,14 @@ repos:
 
 ## Docker
 
-A Docker image is availlable at [`ghcr.io/oxipng/oxipng`](https://github.com/oxipng/oxipng/pkgs/container/oxipng) for `linux/amd64` and `linux/arm64`.
+A Docker image is availlable at `ghcr.io/shssoichiro/oxipng` for `linux/amd64` and `linux/arm64`.
 
 You can use it the following way:
 
 ```bash
-docker run --rm -v $(pwd):/work ghcr.io/oxipng/oxipng -o 4 /work/file.png
+docker run --rm -v $(pwd):/work ghcr.io/shssoichiro/oxipng -o 4 /work/file.png
 ```
 
-Some older images are also available at [`ghcr.io/shssoichiro/oxipng`](https://github.com/users/shssoichiro/packages/container/package/oxipng).
-
 ## Library Usage
 
 Although originally intended to be used as an executable, Oxipng can also be used as a library in
@@ -124,27 +115,31 @@ input filename, into the [optimize function](https://docs.rs/oxipng/latest/oxipn
 It is recommended to disable the "binary" feature when including Oxipng as a library. Currently, there is
 no simple way to just disable one feature in Cargo, it has to be done by disabling default features
 and specifying the desired ones, for example:
-`oxipng = { version = "10.0", features = ["parallel", "zopfli", "filetime"], default-features = false }`
+`oxipng = { version = "9.0", features = ["parallel", "zopfli", "filetime"], default-features = false }`
 
 ## Software using Oxipng
 
 - [ImageOptim](https://imageoptim.com): Mac app and web service for optimizing images
 - [Squoosh](https://squoosh.app): Web app for optimizing images
 - [FileOptimizer](https://nikkhokkho.sourceforge.io/?page=FileOptimizer): Windows app for optimizing files
-- [Curtail](https://github.com/Huluti/Curtail): Linux app for optimizing images
+- [Curtial](https://github.com/Huluti/Curtail): Linux app for optimizing images
 - [pyoxipng](https://pypi.org/project/pyoxipng/): Python wrapper for Oxipng
 - [jSquash](https://github.com/jamsinclair/jSquash): Collection of WebAssembly image codecs
 - [Trunk](https://trunk.io): Developer experience toolkit for managing code
 
 ## History
 
-Oxipng began in 2015 as a rewrite of the OptiPNG project. The core goal was to implement
-multithreading, which would have been very difficult to do within the existing C codebase of OptiPNG.
+Oxipng began as a complete rewrite of the OptiPNG project,
+which was assumed to be dead as no commit had been made to it since March 2014.
+(OptiPNG has since released a new version, after Oxipng was first released.)
+The name has been changed to avoid confusion and potential legal issues.
+
+The core goal of rewriting OptiPNG was to implement multithreading,
+which would be very difficult to do within the existing C codebase of OptiPNG.
 This also served as an opportunity to choose a more modern, safer language (Rust).
 
-However, Oxipng has evolved considerably since then. While some of the options remain similar to
-OptiPNG, the architecture and capabilities are now quite different. It is not a drop-in
-replacement - if you are migrating from OptiPNG, please check the [help](MANUAL.txt) before use.
+Note that, while similar, Oxipng is not a drop-in replacement for OptiPNG.
+If you are migrating from OptiPNG, please check the [help](MANUAL.txt) before using.
 
 ## Contributing
 
@@ -154,11 +149,42 @@ to submit a fix with the bug report, it is preferred that you do so via pull req
 however you do not need to be a Rust developer to contribute.
 Other contributions (such as improving documentation or translations) are also welcome via GitHub.
 
-## Benchmarks
-
-An independent benchmark is linked here with permission by the author:\
-[oxipng and friends: A comparison of PNG optimization tools](https://op111.net/posts/2025/09/png-compression-oxipng-optipng-fileoptimizer-cwebp/)
-
 ## License
 
 Oxipng is open-source software, distributed under the MIT license.
+
+## Benchmarks
+
+Tested Oxipng 9.0.0 (commit `c16519b38b0519988db625913be919d4f0e42f5d`, compiled
+on `rustc 1.74.0-nightly (7b4d9e155 2023-09-28)`) against OptiPNG version 0.7.7,
+as packaged by Debian unstable, on a Linux 6.5.0-2-amd64 kernel, Intel Core
+i7-12700 CPU (8 performance cores, 4 efficiency cores, 20 threads), DDR5-5200
+RAM in dual channel configuration.
+
+```
+
+Benchmark 1: ./target/release/oxipng -P ./tests/files/rgb_16_should_be_grayscale_8.png
+  Time (mean ± σ):      59.6 ms ±   7.7 ms    [User: 77.4 ms, System: 3.6 ms]
+  Range (min … max):    53.3 ms …  89.9 ms    32 runs
+
+Benchmark 2: optipng -simulate ./tests/files/rgb_16_should_be_grayscale_8.png
+  Time (mean ± σ):     132.4 ms ±   0.8 ms    [User: 132.5 ms, System: 0.6 ms]
+  Range (min … max):   131.8 ms … 134.4 ms    22 runs
+
+Summary
+  ./target/release/oxipng -P ./tests/files/rgb_16_should_be_grayscale_8.png ran
+    2.22 ± 0.29 times faster than optipng -simulate ./tests/files/rgb_16_should_be_grayscale_8.png
+
+Benchmark 1: ./target/release/oxipng -o4 -P ./tests/files/rgb_16_should_be_grayscale_8.png
+  Time (mean ± σ):      88.7 ms ±   4.3 ms    [User: 270.3 ms, System: 11.0 ms]
+  Range (min … max):    86.8 ms … 109.4 ms    26 runs
+
+Benchmark 2: optipng -o 4 -simulate ./tests/files/rgb_16_should_be_grayscale_8.png
+  Time (mean ± σ):     444.9 ms ±   0.3 ms    [User: 444.8 ms, System: 0.7 ms]
+  Range (min … max):   444.4 ms … 445.6 ms    10 runs
+
+Summary
+  ./target/release/oxipng -o4 -P ./tests/files/rgb_16_should_be_grayscale_8.png ran
+    5.01 ± 0.25 times faster than optipng -o 4 -simulate ./tests/files/rgb_16_should_be_grayscale_8.png
+
+```

SECURITY.md

@@ -7,7 +7,7 @@ For this reason, you should attempt to always use the latest released version.
 
 ## Reporting a Vulnerability
 
-To privately report a vulnerability in oxipng, please visit [our advisories page](https://github.com/oxipng/oxipng/security/advisories) and use the button to report a vulnerability.
+To privately report a vulnerability in oxipng, please visit [our advisories page](https://github.com/shssoichiro/oxipng/security/advisories) and use the button to report a vulnerability.
 We will review it as soon as possible.
 
 For vulnerabilities in dependencies, please open a pull request updating the dependency to a patched version.

benches/filters.rs

@@ -13,7 +13,7 @@ fn filters_16_bits_filter_0(b: &mut Bencher) {
     let input = test::black_box(PathBuf::from("tests/files/rgb_16_should_be_rgb_16.png"));
     let png = PngData::new(&input, &Options::default()).unwrap();
 
-    b.iter(|| png.raw.filter_image(FilterStrategy::NONE, false));
+    b.iter(|| png.raw.filter_image(RowFilter::None, false));
 }
 
 #[bench]
@@ -21,7 +21,7 @@ fn filters_8_bits_filter_0(b: &mut Bencher) {
     let input = test::black_box(PathBuf::from("tests/files/rgb_8_should_be_rgb_8.png"));
     let png = PngData::new(&input, &Options::default()).unwrap();
 
-    b.iter(|| png.raw.filter_image(FilterStrategy::NONE, false));
+    b.iter(|| png.raw.filter_image(RowFilter::None, false));
 }
 
 #[bench]
@@ -31,7 +31,7 @@ fn filters_4_bits_filter_0(b: &mut Bencher) {
     ));
     let png = PngData::new(&input, &Options::default()).unwrap();
 
-    b.iter(|| png.raw.filter_image(FilterStrategy::NONE, false));
+    b.iter(|| png.raw.filter_image(RowFilter::None, false));
 }
 
 #[bench]
@@ -41,7 +41,7 @@ fn filters_2_bits_filter_0(b: &mut Bencher) {
     ));
     let png = PngData::new(&input, &Options::default()).unwrap();
 
-    b.iter(|| png.raw.filter_image(FilterStrategy::NONE, false));
+    b.iter(|| png.raw.filter_image(RowFilter::None, false));
 }
 
 #[bench]
@@ -51,7 +51,7 @@ fn filters_1_bits_filter_0(b: &mut Bencher) {
     ));
     let png = PngData::new(&input, &Options::default()).unwrap();
 
-    b.iter(|| png.raw.filter_image(FilterStrategy::NONE, false));
+    b.iter(|| png.raw.filter_image(RowFilter::None, false));
 }
 
 #[bench]
@@ -59,7 +59,7 @@ fn filters_16_bits_filter_1(b: &mut Bencher) {
     let input = test::black_box(PathBuf::from("tests/files/rgb_16_should_be_rgb_16.png"));
     let png = PngData::new(&input, &Options::default()).unwrap();
 
-    b.iter(|| png.raw.filter_image(FilterStrategy::SUB, false));
+    b.iter(|| png.raw.filter_image(RowFilter::Sub, false));
 }
 
 #[bench]
@@ -67,7 +67,7 @@ fn filters_8_bits_filter_1(b: &mut Bencher) {
     let input = test::black_box(PathBuf::from("tests/files/rgb_8_should_be_rgb_8.png"));
     let png = PngData::new(&input, &Options::default()).unwrap();
 
-    b.iter(|| png.raw.filter_image(FilterStrategy::SUB, false));
+    b.iter(|| png.raw.filter_image(RowFilter::Sub, false));
 }
 
 #[bench]
@@ -77,7 +77,7 @@ fn filters_4_bits_filter_1(b: &mut Bencher) {
     ));
     let png = PngData::new(&input, &Options::default()).unwrap();
 
-    b.iter(|| png.raw.filter_image(FilterStrategy::SUB, false));
+    b.iter(|| png.raw.filter_image(RowFilter::Sub, false));
 }
 
 #[bench]
@@ -87,7 +87,7 @@ fn filters_2_bits_filter_1(b: &mut Bencher) {
     ));
     let png = PngData::new(&input, &Options::default()).unwrap();
 
-    b.iter(|| png.raw.filter_image(FilterStrategy::SUB, false));
+    b.iter(|| png.raw.filter_image(RowFilter::Sub, false));
 }
 
 #[bench]
@@ -97,7 +97,7 @@ fn filters_1_bits_filter_1(b: &mut Bencher) {
     ));
     let png = PngData::new(&input, &Options::default()).unwrap();
 
-    b.iter(|| png.raw.filter_image(FilterStrategy::SUB, false));
+    b.iter(|| png.raw.filter_image(RowFilter::Sub, false));
 }
 
 #[bench]
@@ -105,7 +105,7 @@ fn filters_16_bits_filter_2(b: &mut Bencher) {
     let input = test::black_box(PathBuf::from("tests/files/rgb_16_should_be_rgb_16.png"));
     let png = PngData::new(&input, &Options::default()).unwrap();
 
-    b.iter(|| png.raw.filter_image(FilterStrategy::UP, false));
+    b.iter(|| png.raw.filter_image(RowFilter::Up, false));
 }
 
 #[bench]
@@ -113,7 +113,7 @@ fn filters_8_bits_filter_2(b: &mut Bencher) {
     let input = test::black_box(PathBuf::from("tests/files/rgb_8_should_be_rgb_8.png"));
     let png = PngData::new(&input, &Options::default()).unwrap();
 
-    b.iter(|| png.raw.filter_image(FilterStrategy::UP, false));
+    b.iter(|| png.raw.filter_image(RowFilter::Up, false));
 }
 
 #[bench]
@@ -123,7 +123,7 @@ fn filters_4_bits_filter_2(b: &mut Bencher) {
     ));
     let png = PngData::new(&input, &Options::default()).unwrap();
 
-    b.iter(|| png.raw.filter_image(FilterStrategy::UP, false));
+    b.iter(|| png.raw.filter_image(RowFilter::Up, false));
 }
 
 #[bench]
@@ -133,7 +133,7 @@ fn filters_2_bits_filter_2(b: &mut Bencher) {
     ));
     let png = PngData::new(&input, &Options::default()).unwrap();
 
-    b.iter(|| png.raw.filter_image(FilterStrategy::UP, false));
+    b.iter(|| png.raw.filter_image(RowFilter::Up, false));
 }
 
 #[bench]
@@ -143,7 +143,7 @@ fn filters_1_bits_filter_2(b: &mut Bencher) {
     ));
     let png = PngData::new(&input, &Options::default()).unwrap();
 
-    b.iter(|| png.raw.filter_image(FilterStrategy::UP, false));
+    b.iter(|| png.raw.filter_image(RowFilter::Up, false));
 }
 
 #[bench]
@@ -151,7 +151,7 @@ fn filters_16_bits_filter_3(b: &mut Bencher) {
     let input = test::black_box(PathBuf::from("tests/files/rgb_16_should_be_rgb_16.png"));
     let png = PngData::new(&input, &Options::default()).unwrap();
 
-    b.iter(|| png.raw.filter_image(FilterStrategy::AVERAGE, false));
+    b.iter(|| png.raw.filter_image(RowFilter::Average, false));
 }
 
 #[bench]
@@ -159,7 +159,7 @@ fn filters_8_bits_filter_3(b: &mut Bencher) {
     let input = test::black_box(PathBuf::from("tests/files/rgb_8_should_be_rgb_8.png"));
     let png = PngData::new(&input, &Options::default()).unwrap();
 
-    b.iter(|| png.raw.filter_image(FilterStrategy::AVERAGE, false));
+    b.iter(|| png.raw.filter_image(RowFilter::Average, false));
 }
 
 #[bench]
@@ -169,7 +169,7 @@ fn filters_4_bits_filter_3(b: &mut Bencher) {
     ));
     let png = PngData::new(&input, &Options::default()).unwrap();
 
-    b.iter(|| png.raw.filter_image(FilterStrategy::AVERAGE, false));
+    b.iter(|| png.raw.filter_image(RowFilter::Average, false));
 }
 
 #[bench]
@@ -179,7 +179,7 @@ fn filters_2_bits_filter_3(b: &mut Bencher) {
     ));
     let png = PngData::new(&input, &Options::default()).unwrap();
 
-    b.iter(|| png.raw.filter_image(FilterStrategy::AVERAGE, false));
+    b.iter(|| png.raw.filter_image(RowFilter::Average, false));
 }
 
 #[bench]
@@ -189,7 +189,7 @@ fn filters_1_bits_filter_3(b: &mut Bencher) {
     ));
     let png = PngData::new(&input, &Options::default()).unwrap();
 
-    b.iter(|| png.raw.filter_image(FilterStrategy::AVERAGE, false));
+    b.iter(|| png.raw.filter_image(RowFilter::Average, false));
 }
 
 #[bench]
@@ -197,7 +197,7 @@ fn filters_16_bits_filter_4(b: &mut Bencher) {
     let input = test::black_box(PathBuf::from("tests/files/rgb_16_should_be_rgb_16.png"));
     let png = PngData::new(&input, &Options::default()).unwrap();
 
-    b.iter(|| png.raw.filter_image(FilterStrategy::PAETH, false));
+    b.iter(|| png.raw.filter_image(RowFilter::Paeth, false));
 }
 
 #[bench]
@@ -205,7 +205,7 @@ fn filters_8_bits_filter_4(b: &mut Bencher) {
     let input = test::black_box(PathBuf::from("tests/files/rgb_8_should_be_rgb_8.png"));
     let png = PngData::new(&input, &Options::default()).unwrap();
 
-    b.iter(|| png.raw.filter_image(FilterStrategy::PAETH, false));
+    b.iter(|| png.raw.filter_image(RowFilter::Paeth, false));
 }
 
 #[bench]
@@ -215,7 +215,7 @@ fn filters_4_bits_filter_4(b: &mut Bencher) {
     ));
     let png = PngData::new(&input, &Options::default()).unwrap();
 
-    b.iter(|| png.raw.filter_image(FilterStrategy::PAETH, false));
+    b.iter(|| png.raw.filter_image(RowFilter::Paeth, false));
 }
 
 #[bench]
@@ -225,7 +225,7 @@ fn filters_2_bits_filter_4(b: &mut Bencher) {
     ));
     let png = PngData::new(&input, &Options::default()).unwrap();
 
-    b.iter(|| png.raw.filter_image(FilterStrategy::PAETH, false));
+    b.iter(|| png.raw.filter_image(RowFilter::Paeth, false));
 }
 
 #[bench]
@@ -235,7 +235,7 @@ fn filters_1_bits_filter_4(b: &mut Bencher) {
     ));
     let png = PngData::new(&input, &Options::default()).unwrap();
 
-    b.iter(|| png.raw.filter_image(FilterStrategy::PAETH, false));
+    b.iter(|| png.raw.filter_image(RowFilter::Paeth, false));
 }
 
 #[bench]
@@ -243,7 +243,7 @@ fn filters_16_bits_filter_5(b: &mut Bencher) {
     let input = test::black_box(PathBuf::from("tests/files/rgb_16_should_be_rgb_16.png"));
     let png = PngData::new(&input, &Options::default()).unwrap();
 
-    b.iter(|| png.raw.filter_image(FilterStrategy::MinSum, false));
+    b.iter(|| png.raw.filter_image(RowFilter::MinSum, false));
 }
 
 #[bench]
@@ -251,7 +251,7 @@ fn filters_8_bits_filter_5(b: &mut Bencher) {
     let input = test::black_box(PathBuf::from("tests/files/rgb_8_should_be_rgb_8.png"));
     let png = PngData::new(&input, &Options::default()).unwrap();
 
-    b.iter(|| png.raw.filter_image(FilterStrategy::MinSum, false));
+    b.iter(|| png.raw.filter_image(RowFilter::MinSum, false));
 }
 
 #[bench]
@@ -261,7 +261,7 @@ fn filters_4_bits_filter_5(b: &mut Bencher) {
     ));
     let png = PngData::new(&input, &Options::default()).unwrap();
 
-    b.iter(|| png.raw.filter_image(FilterStrategy::MinSum, false));
+    b.iter(|| png.raw.filter_image(RowFilter::MinSum, false));
 }
 
 #[bench]
@@ -271,7 +271,7 @@ fn filters_2_bits_filter_5(b: &mut Bencher) {
     ));
     let png = PngData::new(&input, &Options::default()).unwrap();
 
-    b.iter(|| png.raw.filter_image(FilterStrategy::MinSum, false));
+    b.iter(|| png.raw.filter_image(RowFilter::MinSum, false));
 }
 
 #[bench]
@@ -281,5 +281,5 @@ fn filters_1_bits_filter_5(b: &mut Bencher) {
     ));
     let png = PngData::new(&input, &Options::default()).unwrap();
 
-    b.iter(|| png.raw.filter_image(FilterStrategy::MinSum, false));
+    b.iter(|| png.raw.filter_image(RowFilter::MinSum, false));
 }

benches/interlacing.rs

@@ -13,7 +13,7 @@ fn interlacing_16_bits(b: &mut Bencher) {
     let input = test::black_box(PathBuf::from("tests/files/rgb_16_should_be_rgb_16.png"));
     let png = PngData::new(&input, &Options::default()).unwrap();
 
-    b.iter(|| png.raw.change_interlacing(true));
+    b.iter(|| png.raw.change_interlacing(Interlacing::Adam7));
 }
 
 #[bench]
@@ -21,7 +21,7 @@ fn interlacing_8_bits(b: &mut Bencher) {
     let input = test::black_box(PathBuf::from("tests/files/rgb_8_should_be_rgb_8.png"));
     let png = PngData::new(&input, &Options::default()).unwrap();
 
-    b.iter(|| png.raw.change_interlacing(true));
+    b.iter(|| png.raw.change_interlacing(Interlacing::Adam7));
 }
 
 #[bench]
@@ -31,7 +31,7 @@ fn interlacing_4_bits(b: &mut Bencher) {
     ));
     let png = PngData::new(&input, &Options::default()).unwrap();
 
-    b.iter(|| png.raw.change_interlacing(true));
+    b.iter(|| png.raw.change_interlacing(Interlacing::Adam7));
 }
 
 #[bench]
@@ -41,7 +41,7 @@ fn interlacing_2_bits(b: &mut Bencher) {
     ));
     let png = PngData::new(&input, &Options::default()).unwrap();
 
-    b.iter(|| png.raw.change_interlacing(true));
+    b.iter(|| png.raw.change_interlacing(Interlacing::Adam7));
 }
 
 #[bench]
@@ -51,7 +51,7 @@ fn interlacing_1_bits(b: &mut Bencher) {
     ));
     let png = PngData::new(&input, &Options::default()).unwrap();
 
-    b.iter(|| png.raw.change_interlacing(true));
+    b.iter(|| png.raw.change_interlacing(Interlacing::Adam7));
 }
 
 #[bench]
@@ -61,7 +61,7 @@ fn deinterlacing_16_bits(b: &mut Bencher) {
     ));
     let png = PngData::new(&input, &Options::default()).unwrap();
 
-    b.iter(|| png.raw.change_interlacing(false));
+    b.iter(|| png.raw.change_interlacing(Interlacing::None));
 }
 
 #[bench]
@@ -71,7 +71,7 @@ fn deinterlacing_8_bits(b: &mut Bencher) {
     ));
     let png = PngData::new(&input, &Options::default()).unwrap();
 
-    b.iter(|| png.raw.change_interlacing(false));
+    b.iter(|| png.raw.change_interlacing(Interlacing::None));
 }
 
 #[bench]
@@ -81,7 +81,7 @@ fn deinterlacing_4_bits(b: &mut Bencher) {
     ));
     let png = PngData::new(&input, &Options::default()).unwrap();
 
-    b.iter(|| png.raw.change_interlacing(false));
+    b.iter(|| png.raw.change_interlacing(Interlacing::None));
 }
 
 #[bench]
@@ -91,7 +91,7 @@ fn deinterlacing_2_bits(b: &mut Bencher) {
     ));
     let png = PngData::new(&input, &Options::default()).unwrap();
 
-    b.iter(|| png.raw.change_interlacing(false));
+    b.iter(|| png.raw.change_interlacing(Interlacing::None));
 }
 
 #[bench]
@@ -101,5 +101,5 @@ fn deinterlacing_1_bits(b: &mut Bencher) {
     ));
     let png = PngData::new(&input, &Options::default()).unwrap();
 
-    b.iter(|| png.raw.change_interlacing(false));
+    b.iter(|| png.raw.change_interlacing(Interlacing::None));
 }

benches/strategies.rs

@@ -13,7 +13,7 @@ fn filters_minsum(b: &mut Bencher) {
     let input = test::black_box(PathBuf::from("tests/files/rgb_8_should_be_rgb_8.png"));
     let png = PngData::new(&input, &Options::default()).unwrap();
 
-    b.iter(|| png.raw.filter_image(FilterStrategy::MinSum, false));
+    b.iter(|| png.raw.filter_image(RowFilter::MinSum, false));
 }
 
 #[bench]
@@ -21,7 +21,7 @@ fn filters_entropy(b: &mut Bencher) {
     let input = test::black_box(PathBuf::from("tests/files/rgb_8_should_be_rgb_8.png"));
     let png = PngData::new(&input, &Options::default()).unwrap();
 
-    b.iter(|| png.raw.filter_image(FilterStrategy::Entropy, false));
+    b.iter(|| png.raw.filter_image(RowFilter::Entropy, false));
 }
 
 #[bench]
@@ -29,7 +29,7 @@ fn filters_bigrams(b: &mut Bencher) {
     let input = test::black_box(PathBuf::from("tests/files/rgb_8_should_be_rgb_8.png"));
     let png = PngData::new(&input, &Options::default()).unwrap();
 
-    b.iter(|| png.raw.filter_image(FilterStrategy::Bigrams, false));
+    b.iter(|| png.raw.filter_image(RowFilter::Bigrams, false));
 }
 
 #[bench]
@@ -37,7 +37,7 @@ fn filters_bigent(b: &mut Bencher) {
     let input = test::black_box(PathBuf::from("tests/files/rgb_8_should_be_rgb_8.png"));
     let png = PngData::new(&input, &Options::default()).unwrap();
 
-    b.iter(|| png.raw.filter_image(FilterStrategy::BigEnt, false));
+    b.iter(|| png.raw.filter_image(RowFilter::BigEnt, false));
 }
 
 #[bench]
@@ -45,13 +45,5 @@ fn filters_brute(b: &mut Bencher) {
     let input = test::black_box(PathBuf::from("tests/files/rgb_8_should_be_rgb_8.png"));
     let png = PngData::new(&input, &Options::default()).unwrap();
 
-    b.iter(|| {
-        png.raw.filter_image(
-            FilterStrategy::Brute {
-                num_lines: 4,
-                level: 1,
-            },
-            false,
-        )
-    });
+    b.iter(|| png.raw.filter_image(RowFilter::Brute, false));
 }

benches/zopfli.rs

@@ -3,18 +3,21 @@
 extern crate oxipng;
 extern crate test;
 
-use std::path::PathBuf;
+use std::{num::NonZeroU8, path::PathBuf};
 
 use oxipng::{internal_tests::*, *};
 use test::Bencher;
 
+// SAFETY: trivially safe. Stopgap solution until const unwrap is stabilized.
+const DEFAULT_ZOPFLI_ITERATIONS: NonZeroU8 = unsafe { NonZeroU8::new_unchecked(15) };
+
 #[bench]
 fn zopfli_16_bits_strategy_0(b: &mut Bencher) {
     let input = test::black_box(PathBuf::from("tests/files/rgb_16_should_be_rgb_16.png"));
     let png = PngData::new(&input, &Options::default()).unwrap();
 
     b.iter(|| {
-        zopfli_deflate(png.raw.data.as_ref(), ZopfliOptions::default()).ok();
+        zopfli_deflate(png.raw.data.as_ref(), DEFAULT_ZOPFLI_ITERATIONS).ok();
     });
 }
 
@@ -24,7 +27,7 @@ fn zopfli_8_bits_strategy_0(b: &mut Bencher) {
     let png = PngData::new(&input, &Options::default()).unwrap();
 
     b.iter(|| {
-        zopfli_deflate(png.raw.data.as_ref(), ZopfliOptions::default()).ok();
+        zopfli_deflate(png.raw.data.as_ref(), DEFAULT_ZOPFLI_ITERATIONS).ok();
     });
 }
 
@@ -36,7 +39,7 @@ fn zopfli_4_bits_strategy_0(b: &mut Bencher) {
     let png = PngData::new(&input, &Options::default()).unwrap();
 
     b.iter(|| {
-        zopfli_deflate(png.raw.data.as_ref(), ZopfliOptions::default()).ok();
+        zopfli_deflate(png.raw.data.as_ref(), DEFAULT_ZOPFLI_ITERATIONS).ok();
     });
 }
 
@@ -48,7 +51,7 @@ fn zopfli_2_bits_strategy_0(b: &mut Bencher) {
     let png = PngData::new(&input, &Options::default()).unwrap();
 
     b.iter(|| {
-        zopfli_deflate(png.raw.data.as_ref(), ZopfliOptions::default()).ok();
+        zopfli_deflate(png.raw.data.as_ref(), DEFAULT_ZOPFLI_ITERATIONS).ok();
     });
 }
 
@@ -60,6 +63,6 @@ fn zopfli_1_bits_strategy_0(b: &mut Bencher) {
     let png = PngData::new(&input, &Options::default()).unwrap();
 
     b.iter(|| {
-        zopfli_deflate(png.raw.data.as_ref(), ZopfliOptions::default()).ok();
+        zopfli_deflate(png.raw.data.as_ref(), DEFAULT_ZOPFLI_ITERATIONS).ok();
     });
 }

src/apng.rs

@@ -1,7 +1,9 @@
+use std::io::Write;
+
 use crate::{
-    PngResult,
     error::PngError,
     headers::{read_be_u16, read_be_u32},
+    PngResult,
 };
 
 #[derive(Debug, Clone)]
@@ -29,11 +31,11 @@ pub struct Frame {
 
 impl Frame {
     /// Construct a new Frame from the data in a fcTL chunk
-    pub fn from_fctl_data(byte_data: &[u8]) -> PngResult<Self> {
+    pub fn from_fctl_data(byte_data: &[u8]) -> PngResult<Frame> {
         if byte_data.len() < 26 {
             return Err(PngError::TruncatedData);
         }
-        Ok(Self {
+        Ok(Frame {
             width: read_be_u32(&byte_data[4..8]),
             height: read_be_u32(&byte_data[8..12]),
             x_offset: read_be_u32(&byte_data[12..16]),
@@ -50,14 +52,15 @@ impl Frame {
     #[must_use]
     pub fn fctl_data(&self, sequence_number: u32) -> Vec<u8> {
         let mut byte_data = Vec::with_capacity(26);
-        byte_data.extend_from_slice(&sequence_number.to_be_bytes());
-        byte_data.extend_from_slice(&self.width.to_be_bytes());
-        byte_data.extend_from_slice(&self.height.to_be_bytes());
-        byte_data.extend_from_slice(&self.x_offset.to_be_bytes());
-        byte_data.extend_from_slice(&self.y_offset.to_be_bytes());
-        byte_data.extend_from_slice(&self.delay_num.to_be_bytes());
-        byte_data.extend_from_slice(&self.delay_den.to_be_bytes());
-        byte_data.extend_from_slice(&[self.dispose_op, self.blend_op]);
+        byte_data.write_all(&sequence_number.to_be_bytes()).unwrap();
+        byte_data.write_all(&self.width.to_be_bytes()).unwrap();
+        byte_data.write_all(&self.height.to_be_bytes()).unwrap();
+        byte_data.write_all(&self.x_offset.to_be_bytes()).unwrap();
+        byte_data.write_all(&self.y_offset.to_be_bytes()).unwrap();
+        byte_data.write_all(&self.delay_num.to_be_bytes()).unwrap();
+        byte_data.write_all(&self.delay_den.to_be_bytes()).unwrap();
+        byte_data.push(self.dispose_op);
+        byte_data.push(self.blend_op);
         byte_data
     }
 
@@ -65,8 +68,8 @@ impl Frame {
     #[must_use]
     pub fn fdat_data(&self, sequence_number: u32) -> Vec<u8> {
         let mut byte_data = Vec::with_capacity(4 + self.data.len());
-        byte_data.extend_from_slice(&sequence_number.to_be_bytes());
-        byte_data.extend_from_slice(&self.data);
+        byte_data.write_all(&sequence_number.to_be_bytes()).unwrap();
+        byte_data.write_all(&self.data).unwrap();
         byte_data
     }
 }

src/atomicmin.rs

@@ -15,7 +15,11 @@ impl AtomicMin {
 
     pub fn get(&self) -> Option<usize> {
         let val = self.val.load(SeqCst);
-        if val == usize::MAX { None } else { Some(val) }
+        if val == usize::MAX {
+            None
+        } else {
+            Some(val)
+        }
     }
 
     /// Try a new value, returning true if it is the new minimum

src/cli.rs

@@ -1,18 +1,9 @@
-use std::{num::NonZeroU64, path::PathBuf};
+use std::path::PathBuf;
 
-use clap::builder::Styles;
-use clap::builder::styling::{AnsiColor, Effects};
-use clap::{Arg, ArgAction, Command, builder::ArgPredicate, value_parser};
-use parse_size::parse_size;
+use clap::{value_parser, Arg, ArgAction, Command};
 
 include!("display_chunks.rs");
 
-const STYLES: Styles = Styles::styled()
-    .header(AnsiColor::Green.on_default().effects(Effects::BOLD))
-    .usage(AnsiColor::Green.on_default().effects(Effects::BOLD))
-    .literal(AnsiColor::Cyan.on_default().effects(Effects::BOLD))
-    .placeholder(AnsiColor::Cyan.on_default());
-
 pub fn build_command() -> Command {
     // Note: clap 'wrap_help' is enabled to automatically wrap lines according to terminal width.
     // To keep things tidy though, short help descriptions should be no more than 54 characters,
@@ -23,7 +14,6 @@ pub fn build_command() -> Command {
         .version(env!("CARGO_PKG_VERSION"))
         .author("Joshua Holmer <jholmer.in@gmail.com>")
         .about("Losslessly improve compression of PNG files")
-        .styles(STYLES)
         .arg(
             Arg::new("files")
                 .help("File(s) to compress (use '-' for stdin)")
@@ -41,14 +31,14 @@ Set the optimization level preset. The default level 2 is quite fast and provide
 compression. Lower levels are faster, higher levels provide better compression, though \
 with increasingly diminishing returns.
 
-    0   => --zc 5  --fast              (filter chosen heuristically)
-    1   => --zc 10 --fast              (filter chosen heuristically)
-    2   => --zc 11 -f 0,1,6,7 --fast
-    3   => --zc 11 -f 0,7,8,9         --brute-level 1 --brute-lines 3
-    4   => --zc 12 -f 0,7,8,9         --brute-level 1 --brute-lines 4
-    5   => --zc 12 -f 0,1,2,5,6,7,8,9 --brute-level 4 --brute-lines 4
-    6   => --zc 12 -f 0-9             --brute-level 5 --brute-lines 8
-    max => (stable alias for the maximum level)
+    0   => --zc 5 --fast               (1 trial, determined heuristically)
+    1   => --zc 10 --fast              (1 trial, determined heuristically)
+    2   => --zc 11 -f 0,1,6,7 --fast   (4 fast trials, 1 main trial)
+    3   => --zc 11 -f 0,7,8,9          (4 trials)
+    4   => --zc 12 -f 0,7,8,9          (4 trials)
+    5   => --zc 12 -f 0,1,2,5,6,7,8,9  (8 trials)
+    6   => --zc 12 -f 0-9              (10 trials)
+    max =>                             (stable alias for the max level)
 
 Manually specifying a compression option (zc, f, etc.) will override the optimization \
 preset, regardless of the order you write the arguments.")
@@ -107,10 +97,10 @@ Note that this will not preserve the directory structure of the input files when
                 .action(ArgAction::SetTrue),
         )
         .arg(
-            Arg::new("dry-run")
+            Arg::new("pretend")
                 .help("Do not write any files, only show compression results")
-                .short('d')
-                .long("dry-run")
+                .short('P')
+                .long("pretend")
                 .action(ArgAction::SetTrue),
         )
         .arg(
@@ -133,14 +123,10 @@ Strip metadata chunks, where <mode> is one of:
 
 CAUTION: 'all' will convert APNGs to standard PNGs.
 
-Please note that regardless of any options set, some chunks will necessarily be stripped \
-when invalidated by the optimization:
-    bKGD, sBIT, hIST: Stripped if the color type or bit depth changes.
-    iDOT: Always stripped.
-    caBX: Stripped if it contains C2PA metadata. If explicitly retained by `--keep`, \
-    optimization will be aborted.
+Note that 'bKGD', 'sBIT' and 'hIST' will be forcibly stripped if the color type or bit \
+depth is changed, regardless of any options set.
 
-The default when --strip is not passed is to keep all chunks that remain valid.",
+The default when --strip is not passed is to keep all metadata.",
                        DISPLAY_CHUNKS
                            .iter()
                            .map(|c| String::from_utf8_lossy(c))
@@ -177,23 +163,24 @@ transformation and may be unsuitable for some applications.")
                 .action(ArgAction::SetTrue),
         )
         .arg(
+            // Note: The default value is not explicitly set here, as it is dependant on the `--nx` flag.
             Arg::new("interlace")
-                .help("Set PNG interlacing (off, on, keep)")
+                .help("Set PNG interlacing type (0, 1, keep) [default: 0]")
                 .long_help("\
-Set the PNG interlacing mode, where <mode> is one of:
+Set the PNG interlacing type, where <type> is one of:
 
-    off   =>  Remove interlacing from all images that are processed
-    on    =>  Apply Adam7 interlacing on all images that are processed
-    keep  =>  Keep the existing interlacing mode of each image
+    0     =>  Remove interlacing from all images that are processed
+    1     =>  Apply Adam7 interlacing on all images that are processed
+    keep  =>  Keep the existing interlacing type of each image
 
 Note that interlacing can add 25-50% to the size of an optimized image. Only use it if you \
-believe the benefits outweigh the costs for your use case.")
+believe the benefits outweigh the costs for your use case.
+
+[default: 0]")
                 .short('i')
                 .long("interlace")
-                .value_name("mode")
-                .value_parser(["off", "on", "keep", "0", "1"])
-                .default_value("off")
-                .default_value_if("no-reductions", ArgPredicate::IsPresent, "keep")
+                .value_name("type")
+                .value_parser(["0", "1", "keep"])
                 .hide_possible_values(true),
         )
         .arg(
@@ -212,7 +199,7 @@ losslessly.")
         )
         .arg(
             Arg::new("verbose")
-                .help("Show per-file info (use multiple times for more detail)")
+                .help("Run in verbose mode (use twice to increase verbosity)")
                 .short('v')
                 .long("verbose")
                 .action(ArgAction::Count)
@@ -220,20 +207,12 @@ losslessly.")
         )
         .arg(
             Arg::new("quiet")
-                .help("Suppress all output messages")
+                .help("Run in quiet mode")
                 .short('q')
                 .long("quiet")
                 .action(ArgAction::SetTrue)
                 .conflicts_with("verbose"),
         )
-        .arg(
-            Arg::new("json")
-                .help("Print results as JSON")
-                .short('j')
-                .long("json")
-                .action(ArgAction::SetTrue)
-                .conflicts_with("stdout"),
-        )
         .arg(
             Arg::new("filters")
                 .help("Filters to try (0-9; see '--help' for details)")
@@ -250,9 +229,9 @@ PNG delta filters (apply the same filter to every line)
 
 Heuristic strategies (try to find the best delta filter for each line)
     5  =>  MinSum    Minimum sum of absolute differences
-    6  =>  Entropy   Smallest Shannon entropy
+    6  =>  Entropy   Highest Shannon entropy
     7  =>  Bigrams   Lowest count of distinct bigrams
-    8  =>  BigEnt    Smallest Shannon entropy of bigrams
+    8  =>  BigEnt    Highest Shannon entropy of bigrams
     9  =>  Brute     Smallest compressed size (slow)
 
 The default value depends on the optimization level preset.")
@@ -298,8 +277,6 @@ The default value depends on the optimization level preset.")
         .arg(
             Arg::new("no-palette-reduction")
                 .help("Do not change color palette")
-                .long_help("\
-Do not convert to indexed and do not modify an existing color palette.")
                 .long("np")
                 .action(ArgAction::SetTrue),
         )
@@ -332,7 +309,7 @@ compressed chunks (such as iCCP) will also be disabled. Note that the combinatio
                 .help("Disable checksum validation")
                 .long_help("\
 Do not perform checksum validation of PNG chunks. This may allow some files with errors to \
-be processed successfully. The output will always have correct checksums.")
+be processed successfully.")
                 .long("fix")
                 .action(ArgAction::SetTrue),
         )
@@ -348,8 +325,7 @@ be processed successfully. The output will always have correct checksums.")
                 .long_help("\
 Use the much slower but stronger Zopfli compressor for main compression trials. \
 Recommended use is with '-o max' and '--fast'.")
-                .short('z')
-                .short_alias('Z') // Kept for backwards compatibility
+                .short('Z')
                 .long("zopfli")
                 .action(ArgAction::SetTrue),
         )
@@ -362,40 +338,9 @@ speed up compression for large files. This option requires '--zopfli' to be set.
                 .long("zi")
                 .value_name("iterations")
                 .default_value("15")
-                .value_parser(value_parser!(NonZeroU64))
+                .value_parser(1..=255)
                 .requires("zopfli"),
         )
-        .arg(
-            Arg::new("iterations-without-improvement")
-                .hide_short_help(true)
-                .long_help("\
-Stop Zopfli compression after this number of iterations without improvement. Use this in \
-conjunction with a high value for '--zi' to achieve better compression in reasonable time.")
-                .long("ziwi")
-                .value_name("iterations")
-                .value_parser(value_parser!(NonZeroU64))
-                .requires("zopfli"),
-        )
-        .arg(
-            Arg::new("brute-level")
-                .hide_short_help(true)
-                .long_help("\
-Set the libdeflate compression level to use with the Brute filter strategy. Sane values \
-are 1-5. Higher values are not necessarily better.")
-                .long("brute-level")
-                .value_name("level")
-                .value_parser(1..=12),
-        )
-        .arg(
-            Arg::new("brute-lines")
-                .hide_short_help(true)
-                .long_help("\
-Set the number of lines to compress at once with the Brute filter strategy. Sane values \
-are 2-16. Higher values are not necessarily better.")
-                .long("brute-lines")
-                .value_name("lines")
-                .value_parser(value_parser!(usize)),
-        )
         .arg(
             Arg::new("timeout")
                 .help("Maximum amount of time to spend on optimizations")
@@ -409,21 +354,6 @@ high compression levels.")
                 .value_name("secs")
                 .value_parser(value_parser!(u64)),
         )
-        .arg(
-            Arg::new("max-size")
-                .help("Skip image if the decompressed size exceeds this limit")
-                .long_help("\
-Maximum size to allow for the input image. If the raw, decompressed image data (or the \
-file size) of the image exceeds this size, it will be skipped. This is useful for limiting \
-memory usage or avoiding long processing times on large images. The value may be specified \
-with a unit suffix such as k, KB, m, MB, etc.
-
-The decompressed size of an image is roughly equal to width * height * bit-depth / 8. E.g. \
-a 1920x1080 image with 24-bit color depth would be roughly 6MB.")
-                .long("max-raw-size")
-                .value_name("bytes")
-                .value_parser(|s: &str| parse_size(s)),
-        )
         .arg(
             Arg::new("threads")
                 .help("Number of threads to use [default: num logical CPUs]")

src/colors.rs

@@ -116,7 +116,7 @@ impl TryFrom<u8> for BitDepth {
             4 => Ok(Self::Four),
             8 => Ok(Self::Eight),
             16 => Ok(Self::Sixteen),
-            _ => Err(PngError::InvalidData),
+            _ => Err(PngError::new("Unexpected bit depth")),
         }
     }
 }

src/deflate/deflater.rs

@@ -22,7 +22,7 @@ pub fn inflate(data: &[u8], out_size: usize) -> PngResult<Vec<u8>> {
         .zlib_decompress(data, &mut dest)
         .map_err(|err| match err {
             DecompressionError::BadData => PngError::InvalidData,
-            DecompressionError::InsufficientSpace => PngError::InflatedDataTooLong(out_size),
+            DecompressionError::InsufficientSpace => PngError::new("inflated data too long"),
         })?;
     dest.truncate(len);
     Ok(dest)

src/deflate/mod.rs

@@ -1,20 +1,19 @@
 mod deflater;
+#[cfg(feature = "zopfli")]
+use std::num::NonZeroU8;
 use std::{fmt, fmt::Display};
 
 pub use deflater::{crc32, deflate, inflate};
 
 use crate::{PngError, PngResult};
-
 #[cfg(feature = "zopfli")]
 mod zopfli_oxipng;
 #[cfg(feature = "zopfli")]
-pub use zopfli::Options as ZopfliOptions;
-#[cfg(feature = "zopfli")]
 pub use zopfli_oxipng::deflate as zopfli_deflate;
 
 /// DEFLATE algorithms supported by oxipng (for use in [`Options`][crate::Options])
 #[derive(Clone, Copy, Debug, PartialEq, Eq)]
-pub enum Deflater {
+pub enum Deflaters {
     /// Use libdeflater.
     Libdeflater {
         /// Which compression level to use on the file (0-12)
@@ -22,15 +21,20 @@ pub enum Deflater {
     },
     #[cfg(feature = "zopfli")]
     /// Use the better but slower Zopfli implementation
-    Zopfli(ZopfliOptions),
+    Zopfli {
+        /// The number of compression iterations to do. 15 iterations are fine
+        /// for small files, but bigger files will need to be compressed with
+        /// less iterations, or else they will be too slow.
+        iterations: NonZeroU8,
+    },
 }
 
-impl Deflater {
+impl Deflaters {
     pub(crate) fn deflate(self, data: &[u8], max_size: Option<usize>) -> PngResult<Vec<u8>> {
         let compressed = match self {
             Self::Libdeflater { compression } => deflate(data, compression, max_size)?,
             #[cfg(feature = "zopfli")]
-            Self::Zopfli(options) => zopfli_deflate(data, options)?,
+            Self::Zopfli { iterations } => zopfli_deflate(data, iterations)?,
         };
         if let Some(max) = max_size {
             if compressed.len() > max {
@@ -41,13 +45,13 @@ impl Deflater {
     }
 }
 
-impl Display for Deflater {
+impl Display for Deflaters {
     #[inline]
     fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
         match self {
             Self::Libdeflater { compression } => write!(f, "zc = {compression}"),
             #[cfg(feature = "zopfli")]
-            Self::Zopfli(options) => write!(f, "zopfli, zi = {}", options.iteration_count),
+            Self::Zopfli { iterations } => write!(f, "zopfli, zi = {iterations}"),
         }
     }
 }

src/deflate/zopfli_oxipng.rs

@@ -1,13 +1,19 @@
+use std::num::NonZeroU8;
+
 use crate::{PngError, PngResult};
 
-pub fn deflate(data: &[u8], options: zopfli::Options) -> PngResult<Vec<u8>> {
+pub fn deflate(data: &[u8], iterations: NonZeroU8) -> PngResult<Vec<u8>> {
     let mut output = Vec::with_capacity(data.len());
+    let options = zopfli::Options {
+        iteration_count: iterations.into(),
+        ..Default::default()
+    };
     // Since Rust v1.74, passing &[u8] directly into zopfli causes a regression in compressed size
     // for some files. Wrapping the slice in another Read implementer such as Box fixes it for now.
     match zopfli::compress(options, zopfli::Format::Zlib, Box::new(data), &mut output) {
-        Ok(()) => (),
+        Ok(_) => (),
         Err(_) => return Err(PngError::new("Failed to compress in zopfli")),
-    }
+    };
     output.shrink_to_fit();
     Ok(output)
 }

src/error.rs

@@ -2,22 +2,20 @@ use std::{error::Error, fmt};
 
 use crate::colors::{BitDepth, ColorType};
 
-#[derive(Debug)]
+#[derive(Debug, Clone)]
 #[non_exhaustive]
 pub enum PngError {
-    APNGOutOfOrder,
-    C2PAMetadataPreventsChanges,
-    ChunkMissing(&'static str),
-    CRCMismatch([u8; 4]),
     DeflatedDataTooLong(usize),
-    IncorrectDataLength(usize, usize),
-    InflatedDataTooLong(usize),
-    InvalidData,
-    InvalidDepthForType(BitDepth, ColorType),
+    TimedOut,
     NotPNG,
-    ReadFailed(String, std::io::Error),
+    APNGNotSupported,
+    APNGOutOfOrder,
+    InvalidData,
     TruncatedData,
-    WriteFailed(String, std::io::Error),
+    ChunkMissing(&'static str),
+    InvalidDepthForType(BitDepth, ColorType),
+    IncorrectDataLength(usize, usize),
+    C2PAMetadataPreventsChanges,
     Other(Box<str>),
 }
 
@@ -28,34 +26,27 @@ impl fmt::Display for PngError {
     #[cold]
     fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
         match *self {
-            Self::APNGOutOfOrder => f.write_str("APNG chunks are out of order"),
-            Self::C2PAMetadataPreventsChanges => f.write_str(
-                "The image contains C2PA manifest that would be invalidated by any file changes",
-            ),
-            Self::ChunkMissing(s) => write!(f, "Chunk {s} missing or empty"),
-            Self::CRCMismatch(ref c) => write!(
-                f,
-                "CRC mismatch in {} chunk; May be recoverable by using --fix",
-                String::from_utf8_lossy(c)
-            ),
-            Self::DeflatedDataTooLong(_) => f.write_str("Deflated data too long"),
-            Self::IncorrectDataLength(l1, l2) => write!(
+            PngError::DeflatedDataTooLong(_) => f.write_str("deflated data too long"),
+            PngError::TimedOut => f.write_str("timed out"),
+            PngError::NotPNG => f.write_str("Invalid header detected; Not a PNG file"),
+            PngError::InvalidData => f.write_str("Invalid data found; unable to read PNG file"),
+            PngError::TruncatedData => {
+                f.write_str("Missing data in the file; the file is truncated")
+            }
+            PngError::APNGNotSupported => f.write_str("APNG files are not (yet) supported"),
+            PngError::APNGOutOfOrder => f.write_str("APNG chunks are out of order"),
+            PngError::ChunkMissing(s) => write!(f, "Chunk {s} missing or empty"),
+            PngError::InvalidDepthForType(d, ref c) => {
+                write!(f, "Invalid bit depth {d} for color type {c}")
+            }
+            PngError::IncorrectDataLength(l1, l2) => write!(
                 f,
                 "Data length {l1} does not match the expected length {l2}"
             ),
-            Self::InflatedDataTooLong(max) => write!(
-                f,
-                "Inflated data would exceed the maximum size ({max} bytes)"
+            PngError::C2PAMetadataPreventsChanges => f.write_str(
+                "The image contains C2PA manifest that would be invalidated by any file changes",
             ),
-            Self::InvalidData => f.write_str("Invalid data found; unable to read PNG file"),
-            Self::InvalidDepthForType(d, ref c) => {
-                write!(f, "Invalid bit depth {d} for color type {c}")
-            }
-            Self::NotPNG => f.write_str("Invalid header detected; Not a PNG file"),
-            Self::ReadFailed(ref s, ref e) => write!(f, "Failed to read from {s}: {e}"),
-            Self::TruncatedData => f.write_str("Missing data in the file; the file is truncated"),
-            Self::WriteFailed(ref s, ref e) => write!(f, "Failed to write to {s}: {e}"),
-            Self::Other(ref s) => f.write_str(s),
+            PngError::Other(ref s) => f.write_str(s),
         }
     }
 }
@@ -63,7 +54,7 @@ impl fmt::Display for PngError {
 impl PngError {
     #[cold]
     #[must_use]
-    pub fn new(description: &str) -> Self {
-        Self::Other(description.into())
+    pub fn new(description: &str) -> PngError {
+        PngError::Other(description.into())
     }
 }

src/evaluate.rs

@@ -4,42 +4,37 @@
 #[cfg(not(feature = "parallel"))]
 use std::cell::RefCell;
 use std::sync::{
-    Arc,
     atomic::{AtomicUsize, Ordering::*},
+    Arc,
 };
 
-use deflate::Deflater;
+#[cfg(feature = "parallel")]
+use crossbeam_channel::{unbounded, Receiver, Sender};
+use deflate::Deflaters;
 use indexmap::IndexSet;
 use log::trace;
 use rayon::prelude::*;
-#[cfg(feature = "parallel")]
-use std::sync::mpsc::{Receiver, Sender, channel};
 
 #[cfg(not(feature = "parallel"))]
 use crate::rayon;
-use crate::{
-    Deadline, PngError, atomicmin::AtomicMin, deflate, filters::FilterStrategy, png::PngImage,
-};
+use crate::{atomicmin::AtomicMin, deflate, filters::RowFilter, png::PngImage, Deadline, PngError};
 
 pub(crate) struct Candidate {
     pub image: Arc<PngImage>,
-    pub idat_data: Option<Vec<u8>>,
+    pub data: Vec<u8>,
+    pub data_is_compressed: bool,
     pub estimated_output_size: usize,
-    /// The input filter, which is retained for printing and for APNG frames.
-    pub filter: FilterStrategy,
-    /// The filter returned by the filter function, which may be Predefined.
-    /// Use this for the next round to avoid recomputing the filter.
-    pub filter_used: FilterStrategy,
-    /// For determining tie-breaker
+    pub filter: RowFilter,
+    // For determining tie-breaker
     nth: usize,
 }
 
 impl Candidate {
-    fn cmp_key(&self) -> impl Ord + use<> {
+    fn cmp_key(&self) -> impl Ord {
         (
             self.estimated_output_size,
             self.image.data.len(),
-            self.filter.clone(),
+            self.filter,
             // Prefer the later image added (e.g. baseline, which is always added last)
             usize::MAX - self.nth,
         )
@@ -49,8 +44,8 @@ impl Candidate {
 /// Collect image versions and pick one that compresses best
 pub(crate) struct Evaluator {
     deadline: Arc<Deadline>,
-    filters: IndexSet<FilterStrategy>,
-    deflater: Deflater,
+    filters: IndexSet<RowFilter>,
+    deflater: Deflaters,
     optimize_alpha: bool,
     final_round: bool,
     nth: AtomicUsize,
@@ -67,13 +62,13 @@ pub(crate) struct Evaluator {
 impl Evaluator {
     pub fn new(
         deadline: Arc<Deadline>,
-        filters: IndexSet<FilterStrategy>,
-        deflater: Deflater,
+        filters: IndexSet<RowFilter>,
+        deflater: Deflaters,
         optimize_alpha: bool,
         final_round: bool,
     ) -> Self {
         #[cfg(feature = "parallel")]
-        let eval_channel = channel();
+        let eval_channel = unbounded();
         Self {
             deadline,
             filters,
@@ -118,7 +113,7 @@ impl Evaluator {
 
     /// Check if the image is smaller than others
     pub fn try_image(&self, image: Arc<PngImage>) {
-        let description = image.ihdr.color_type.to_string();
+        let description = format!("{}", image.ihdr.color_type);
         self.try_image_with_description(image, &description);
     }
 
@@ -146,37 +141,31 @@ impl Evaluator {
             // which are dangerous to do in side Rayon's loop.
             // Instead, only update (atomic) best size in real time,
             // and the best result later without need for locks.
-            filters_iter.for_each(|filter| {
+            filters_iter.for_each(|&filter| {
                 if deadline.passed() {
                     return;
                 }
-                let (filtered, filter_used) = image.filter_image(filter.clone(), optimize_alpha);
+                let filtered = image.filter_image(filter, optimize_alpha);
                 let idat_data = deflater.deflate(&filtered, best_candidate_size.get());
                 if let Ok(idat_data) = idat_data {
                     let estimated_output_size = image.estimated_output_size(&idat_data);
-                    trace!(
-                        "Eval: {}-bit {:23} {:8}   {} bytes",
-                        image.ihdr.bit_depth, description, filter, estimated_output_size
-                    );
-
-                    // Skip if it exceeds best known size. (This is important to ensure
-                    // the evaluator returns no result when all candidates are too large.)
-                    if let Some(max) = best_candidate_size.get() {
-                        if estimated_output_size > max {
-                            return;
-                        }
-                    }
-
-                    // We only need to retain the IDAT data in the final round
+                    // For the final round we need the IDAT data, otherwise the filtered data
                     let new = Candidate {
                         image: image.clone(),
-                        idat_data: if final_round { Some(idat_data) } else { None },
+                        data: if final_round { idat_data } else { filtered },
+                        data_is_compressed: final_round,
                         estimated_output_size,
-                        filter: filter.clone(),
-                        filter_used,
+                        filter,
                         nth,
                     };
                     best_candidate_size.set_min(estimated_output_size);
+                    trace!(
+                        "Eval: {}-bit {:23} {:8}   {} bytes",
+                        image.ihdr.bit_depth,
+                        description,
+                        filter,
+                        estimated_output_size
+                    );
 
                     #[cfg(feature = "parallel")]
                     {
@@ -193,7 +182,10 @@ impl Evaluator {
                 } else if let Err(PngError::DeflatedDataTooLong(size)) = idat_data {
                     trace!(
                         "Eval: {}-bit {:23} {:8}  >{} bytes",
-                        image.ihdr.bit_depth, description, filter, size
+                        image.ihdr.bit_depth,
+                        description,
+                        filter,
+                        size
                     );
                 }
             });

src/filters.rs

@@ -1,67 +1,30 @@
 use std::{fmt, fmt::Display, mem::transmute};
 
+use crate::error::PngError;
+
 /// Filtering strategy for use in [`Options`][crate::Options]
-#[derive(Debug, PartialEq, Eq, PartialOrd, Ord, Clone, Hash)]
-pub enum FilterStrategy {
-    /// Same filter for all rows
-    Basic(RowFilter),
-    /// Minimum sum of absolute differences
-    MinSum,
-    /// Shannon entropy
-    Entropy,
-    /// Count of distinct bigrams
-    Bigrams,
-    /// Shannon entropy of bigrams
-    BigEnt,
-    /// Deflate compression
-    Brute {
-        /// The number of lines to compress at once
-        num_lines: usize,
-        /// The compression level to use (1-12)
-        level: u8,
-    },
-    /// Predefined filter for each row
-    Predefined(Vec<RowFilter>),
-}
-
-impl FilterStrategy {
-    pub const NONE: Self = Self::Basic(RowFilter::None);
-    pub const SUB: Self = Self::Basic(RowFilter::Sub);
-    pub const UP: Self = Self::Basic(RowFilter::Up);
-    pub const AVERAGE: Self = Self::Basic(RowFilter::Average);
-    pub const PAETH: Self = Self::Basic(RowFilter::Paeth);
-}
-
-impl Display for FilterStrategy {
-    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
-        match self {
-            Self::Basic(filter) => filter.fmt(f),
-            Self::MinSum => "MinSum".fmt(f),
-            Self::Entropy => "Entropy".fmt(f),
-            Self::Bigrams => "Bigrams".fmt(f),
-            Self::BigEnt => "BigEnt".fmt(f),
-            Self::Brute { .. } => "Brute".fmt(f),
-            Self::Predefined(_) => "Predefined".fmt(f),
-        }
-    }
-}
-
-/// PNG delta filters
 #[repr(u8)]
 #[derive(Debug, PartialEq, Eq, PartialOrd, Ord, Clone, Copy, Hash)]
 pub enum RowFilter {
+    // Standard filter types
     None,
     Sub,
     Up,
     Average,
     Paeth,
+    // Heuristic strategies
+    MinSum,
+    Entropy,
+    Bigrams,
+    BigEnt,
+    Brute,
 }
 
 impl TryFrom<u8> for RowFilter {
     type Error = ();
 
     fn try_from(value: u8) -> Result<Self, Self::Error> {
-        if value > 4 {
+        if value > Self::LAST {
             return Err(());
         }
         unsafe { transmute(value as i8) }
@@ -77,6 +40,11 @@ impl Display for RowFilter {
                 Self::Up => "Up",
                 Self::Average => "Average",
                 Self::Paeth => "Paeth",
+                Self::MinSum => "MinSum",
+                Self::Entropy => "Entropy",
+                Self::Bigrams => "Bigrams",
+                Self::BigEnt => "BigEnt",
+                Self::Brute => "Brute",
             },
             f,
         )
@@ -84,7 +52,9 @@ impl Display for RowFilter {
 }
 
 impl RowFilter {
-    pub(crate) const ALL: [Self; 5] = [Self::None, Self::Sub, Self::Up, Self::Average, Self::Paeth];
+    pub const LAST: u8 = Self::Brute as u8;
+    pub(crate) const STANDARD: [Self; 5] =
+        [Self::None, Self::Sub, Self::Up, Self::Average, Self::Paeth];
     pub(crate) const SINGLE_LINE: [Self; 2] = [Self::None, Self::Sub];
 
     pub(crate) fn filter_line(
@@ -127,20 +97,25 @@ impl RowFilter {
             }
             Self::Average => {
                 for (i, byte) in data.iter().enumerate() {
-                    buf.push(byte.wrapping_sub(i.checked_sub(bpp).map_or_else(
-                        || prev_line[i] >> 1,
-                        |x| ((u16::from(data[x]) + u16::from(prev_line[i])) >> 1) as u8,
-                    )));
+                    buf.push(match i.checked_sub(bpp) {
+                        Some(x) => byte.wrapping_sub(
+                            ((u16::from(data[x]) + u16::from(prev_line[i])) >> 1) as u8,
+                        ),
+                        None => byte.wrapping_sub(prev_line[i] >> 1),
+                    });
                 }
             }
             Self::Paeth => {
                 for (i, byte) in data.iter().enumerate() {
-                    buf.push(byte.wrapping_sub(i.checked_sub(bpp).map_or_else(
-                        || prev_line[i],
-                        |x| paeth_predictor(data[x], prev_line[i], prev_line[x]),
-                    )));
+                    buf.push(match i.checked_sub(bpp) {
+                        Some(x) => {
+                            byte.wrapping_sub(paeth_predictor(data[x], prev_line[i], prev_line[x]))
+                        }
+                        None => byte.wrapping_sub(prev_line[i]),
+                    });
                 }
             }
+            _ => unreachable!(),
         }
     }
 
@@ -164,28 +139,10 @@ impl RowFilter {
                         .unwrap_or(i),
                     _ => i - 1,
                 };
-
-                // These assertions help eliminate a few bounds checks in the slice accesses below
-                assert!(prev < pixels.len());
-                assert!(i < prev_pixels.len());
-
                 match self {
-                    Self::None => unreachable!(),
                     Self::Sub => {
-                        // The code below is roughly equivalent to pixels[i][0..color_bytes].copy_from_slice(&pixels[prev][0..color_bytes]),
-                        // if such a thing was possible to do without violating Rust aliasing rules. See:
-                        // https://users.rust-lang.org/t/problem-borrowing-two-elements-of-vec-mutably/21446/2
-
-                        if prev < i {
-                            let (pixels_head, pixels_tail) = pixels.split_at_mut(prev + 1);
-                            pixels_tail[i - prev - 1][0..color_bytes]
-                                .copy_from_slice(&pixels_head[prev][0..color_bytes]);
-                        } else if prev > i {
-                            let (pixels_head, pixels_tail) = pixels.split_at_mut(i + 1);
-                            pixels_head[i][0..color_bytes]
-                                .copy_from_slice(&pixels_tail[prev - i - 1][0..color_bytes]);
-                        } else {
-                            // If prev == i, we'd be copying the pixels onto themselves, which is useless
+                        for j in 0..color_bytes {
+                            pixels[i][j] = pixels[prev][j];
                         }
                     }
                     Self::Up => {
@@ -214,6 +171,7 @@ impl RowFilter {
                             };
                         }
                     }
+                    _ => unreachable!(),
                 }
             }
         }
@@ -225,7 +183,7 @@ impl RowFilter {
         data: &[u8],
         prev_line: &[u8],
         buf: &mut Vec<u8>,
-    ) {
+    ) -> Result<(), PngError> {
         buf.clear();
         buf.reserve(data.len());
         assert!(data.len() >= bpp);
@@ -237,7 +195,10 @@ impl RowFilter {
             Self::Sub => {
                 for (i, &cur) in data.iter().enumerate() {
                     let prev_byte = i.checked_sub(bpp).and_then(|x| buf.get(x).copied());
-                    buf.push(prev_byte.map_or(cur, |b| cur.wrapping_add(b)));
+                    buf.push(match prev_byte {
+                        Some(b) => cur.wrapping_add(b),
+                        None => cur,
+                    });
                 }
             }
             Self::Up => {
@@ -250,10 +211,10 @@ impl RowFilter {
             Self::Average => {
                 for (i, (&cur, &last)) in data.iter().zip(prev_line).enumerate() {
                     let prev_byte = i.checked_sub(bpp).and_then(|x| buf.get(x).copied());
-                    buf.push(cur.wrapping_add(prev_byte.map_or_else(
-                        || last >> 1,
-                        |b| ((u16::from(b) + u16::from(last)) >> 1) as u8,
-                    )));
+                    buf.push(match prev_byte {
+                        Some(b) => cur.wrapping_add(((u16::from(b) + u16::from(last)) >> 1) as u8),
+                        None => cur.wrapping_add(last >> 1),
+                    });
                 }
             }
             Self::Paeth => {
@@ -271,7 +232,9 @@ impl RowFilter {
                     );
                 }
             }
+            _ => return Err(PngError::InvalidData),
         }
+        Ok(())
     }
 }
 

src/headers.rs

@@ -3,11 +3,12 @@ use log::{debug, trace, warn};
 use rgb::{RGB16, RGBA8};
 
 use crate::{
-    Deflater, Options, PngResult,
     colors::{BitDepth, ColorType},
     deflate::{crc32, inflate},
     display_chunks::DISPLAY_CHUNKS,
     error::PngError,
+    interlace::Interlacing,
+    Deflaters, Options, PngResult,
 };
 
 #[derive(Debug, Clone)]
@@ -21,8 +22,8 @@ pub struct IhdrData {
     pub color_type: ColorType,
     /// The bit depth of the image
     pub bit_depth: BitDepth,
-    /// Whether the image is interlaced
-    pub interlaced: bool,
+    /// The interlacing mode of the image
+    pub interlaced: Interlacing,
 }
 
 impl IhdrData {
@@ -35,16 +36,18 @@ impl IhdrData {
 
     /// Byte length of IDAT that is correct for this IHDR
     #[must_use]
-    pub const fn raw_data_size(&self) -> usize {
+    pub fn raw_data_size(&self) -> usize {
         let w = self.width as usize;
         let h = self.height as usize;
         let bpp = self.bpp();
 
-        const fn bitmap_size(bpp: usize, w: usize, h: usize) -> usize {
+        fn bitmap_size(bpp: usize, w: usize, h: usize) -> usize {
             (w * bpp).div_ceil(8) * h
         }
 
-        if self.interlaced {
+        if self.interlaced == Interlacing::None {
+            bitmap_size(bpp, w, h) + h
+        } else {
             let mut size = bitmap_size(bpp, (w + 7) >> 3, (h + 7) >> 3) + ((h + 7) >> 3);
             if w > 4 {
                 size += bitmap_size(bpp, (w + 3) >> 3, (h + 7) >> 3) + ((h + 7) >> 3);
@@ -58,8 +61,6 @@ impl IhdrData {
                 size += bitmap_size(bpp, w >> 1, (h + 1) >> 1) + ((h + 1) >> 1);
             }
             size + bitmap_size(bpp, w, h >> 1) + (h >> 1)
-        } else {
-            bitmap_size(bpp, w, h) + h
         }
     }
 }
@@ -172,7 +173,10 @@ pub fn parse_next_chunk<'a>(
 
     let chunk_bytes = &byte_data[chunk_start..chunk_start + 4 + length as usize];
     if !fix_errors && crc32(chunk_bytes) != crc {
-        return Err(PngError::CRCMismatch(chunk_name.try_into().unwrap()));
+        return Err(PngError::new(&format!(
+            "CRC Mismatch in {} chunk; May be recoverable by using --fix",
+            String::from_utf8_lossy(chunk_name)
+        )));
     }
 
     let name: [u8; 4] = chunk_name.try_into().unwrap();
@@ -205,16 +209,12 @@ pub fn parse_ihdr_chunk(
             },
             4 => ColorType::GrayscaleAlpha,
             6 => ColorType::RGBA,
-            _ => return Err(PngError::InvalidData),
+            _ => return Err(PngError::new("Unexpected color type in header")),
         },
         bit_depth: byte_data[8].try_into()?,
         width: read_be_u32(&byte_data[0..4]),
         height: read_be_u32(&byte_data[4..8]),
-        interlaced: match interlaced {
-            0 => false,
-            1 => true,
-            _ => return Err(PngError::InvalidData),
-        },
+        interlaced: interlaced.try_into()?,
     })
 }
 
@@ -223,7 +223,7 @@ fn palette_to_rgba(
     palette_data: Option<Vec<u8>>,
     trns_data: Option<Vec<u8>>,
 ) -> Result<Vec<RGBA8>, PngError> {
-    let palette_data = palette_data.ok_or(PngError::ChunkMissing("PLTE"))?;
+    let palette_data = palette_data.ok_or_else(|| PngError::new("no palette in indexed image"))?;
     let mut palette: Vec<_> = palette_data
         .chunks_exact(3)
         .map(|color| RGBA8::new(color[0], color[1], color[2], 255))
@@ -248,7 +248,7 @@ pub fn read_be_u32(bytes: &[u8]) -> u32 {
 }
 
 /// Extract and decompress the ICC profile from an iCCP chunk
-pub fn extract_icc(iccp: &Chunk, max_size: Option<usize>) -> Option<Vec<u8>> {
+pub fn extract_icc(iccp: &Chunk) -> Option<Vec<u8>> {
     // Skip (useless) profile name
     let mut data = iccp.data.as_slice();
     loop {
@@ -263,12 +263,9 @@ pub fn extract_icc(iccp: &Chunk, max_size: Option<usize>) -> Option<Vec<u8>> {
     if compression_method != 0 {
         return None; // The profile is supposed to be compressed (method 0)
     }
-    // Libdeflate works with a fixed size buffer. Since the decompressed size is unknown we have to
-    // guess the required buffer size. We allow a fairly generous 10x factor with a minimum of 1000.
-    let mut out_size = (compressed_data.len() * 10).max(1000);
-    // For sanity, impose a default limit of 1MB.
-    out_size = out_size.min(max_size.unwrap_or(1_000_000));
-    match inflate(compressed_data, out_size) {
+    // The decompressed size is unknown so we have to guess the required buffer size
+    let max_size = compressed_data.len() * 2 + 1000;
+    match inflate(compressed_data, max_size) {
         Ok(icc) => Some(icc),
         Err(e) => {
             // Log the error so we can know if the buffer size needs to be adjusted
@@ -279,7 +276,7 @@ pub fn extract_icc(iccp: &Chunk, max_size: Option<usize>) -> Option<Vec<u8>> {
 }
 
 /// Make an iCCP chunk by compressing the ICC profile
-pub fn make_iccp(icc: &[u8], deflater: Deflater, max_size: Option<usize>) -> PngResult<Chunk> {
+pub fn make_iccp(icc: &[u8], deflater: Deflaters, max_size: Option<usize>) -> PngResult<Chunk> {
     let mut compressed = deflater.deflate(icc, max_size)?;
     let mut data = Vec::with_capacity(compressed.len() + 5);
     data.extend(b"icc"); // Profile name - generally unused, can be anything
@@ -334,7 +331,7 @@ pub fn preprocess_chunks(aux_chunks: &mut Vec<Chunk>, opts: &mut Options) {
             trace!("Removing iCCP chunk due to conflict with sRGB chunk");
             aux_chunks.remove(iccp_idx);
             allow_grayscale = true;
-        } else if let Some(icc) = extract_icc(&aux_chunks[iccp_idx], opts.max_decompressed_size) {
+        } else if let Some(icc) = extract_icc(&aux_chunks[iccp_idx]) {
             let intent = if may_replace_iccp {
                 srgb_rendering_intent(&icc)
             } else {
@@ -351,7 +348,7 @@ pub fn preprocess_chunks(aux_chunks: &mut Vec<Chunk>, opts: &mut Options) {
             } else if opts.idat_recoding {
                 // Try recompressing the profile
                 let cur_len = aux_chunks[iccp_idx].data.len();
-                if let Ok(iccp) = make_iccp(&icc, opts.deflater, Some(cur_len - 1)) {
+                if let Ok(iccp) = make_iccp(&icc, opts.deflate, Some(cur_len - 1)) {
                     debug!(
                         "Recompressed iCCP chunk: {} ({} bytes decrease)",
                         iccp.data.len(),
@@ -410,16 +407,4 @@ pub fn postprocess_chunks(aux_chunks: &mut Vec<Chunk>, ihdr: &IhdrData, orig_ihd
             !invalid
         });
     }
-
-    // Remove iDOT which will necessarily be invalid after successful optimization
-    aux_chunks.retain(|c| {
-        let invalid = &c.name == b"iDOT";
-        if invalid {
-            trace!(
-                "Removing {} chunk as it no longer matches the IDAT",
-                std::str::from_utf8(&c.name).unwrap()
-            );
-        }
-        !invalid
-    });
 }

src/interlace.rs

@@ -1,6 +1,42 @@
+use std::{fmt, fmt::Display};
+
 use bitvec::prelude::*;
 
-use crate::{headers::IhdrData, png::PngImage};
+use crate::{headers::IhdrData, png::PngImage, PngError};
+
+/// Whether to enable progressive rendering. See [`Options`][crate::Options])
+#[repr(u8)]
+#[derive(Debug, PartialEq, Eq, Clone, Copy)]
+pub enum Interlacing {
+    /// Makes images load top to bottom.
+    None,
+    /// Makes it possible to render partially-loaded images at lower resolution. Usually increases file sizes.
+    Adam7,
+}
+
+impl TryFrom<u8> for Interlacing {
+    type Error = PngError;
+
+    fn try_from(value: u8) -> Result<Self, Self::Error> {
+        match value {
+            0 => Ok(Self::None),
+            1 => Ok(Self::Adam7),
+            _ => Err(PngError::new("Unexpected interlacing in header")),
+        }
+    }
+}
+
+impl Display for Interlacing {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        Display::fmt(
+            match self {
+                Self::None => "non-interlaced",
+                Self::Adam7 => "interlaced",
+            },
+            f,
+        )
+    }
+}
 
 #[must_use]
 pub fn interlace_image(png: &PngImage) -> PngImage {
@@ -53,7 +89,7 @@ pub fn interlace_image(png: &PngImage) -> PngImage {
         data: output,
         ihdr: IhdrData {
             color_type: png.ihdr.color_type.clone(),
-            interlaced: true,
+            interlaced: Interlacing::Adam7,
             ..png.ihdr
         },
     }
@@ -67,7 +103,7 @@ pub fn deinterlace_image(png: &PngImage) -> PngImage {
         },
         ihdr: IhdrData {
             color_type: png.ihdr.color_type.clone(),
-            interlaced: false,
+            interlaced: Interlacing::None,
             ..png.ihdr
         },
     }
@@ -149,7 +185,7 @@ fn deinterlace_bytes(png: &PngImage) -> Vec<u8> {
     lines.concat()
 }
 
-const fn increment_pass(current_pass: &mut u8, ihdr: &IhdrData) -> bool {
+fn increment_pass(current_pass: &mut u8, ihdr: &IhdrData) -> bool {
     if *current_pass == 7 {
         return false;
     }

src/lib.rs

@@ -1,4 +1,23 @@
-#![cfg_attr(not(feature = "zopfli"), allow(unreachable_patterns))]
+#![warn(trivial_casts, trivial_numeric_casts, unused_import_braces)]
+#![deny(missing_debug_implementations, missing_copy_implementations)]
+#![warn(clippy::expl_impl_clone_on_copy)]
+#![warn(clippy::float_cmp_const)]
+#![warn(clippy::linkedlist)]
+#![warn(clippy::map_flatten)]
+#![warn(clippy::match_same_arms)]
+#![warn(clippy::mem_forget)]
+#![warn(clippy::mut_mut)]
+#![warn(clippy::mutex_integer)]
+#![warn(clippy::needless_continue)]
+#![warn(clippy::path_buf_push_overwrite)]
+#![warn(clippy::range_plus_one)]
+#![allow(clippy::cognitive_complexity)]
+#![allow(clippy::upper_case_acronyms)]
+#![cfg_attr(
+    not(feature = "zopfli"),
+    allow(irrefutable_let_patterns),
+    allow(unreachable_patterns)
+)]
 
 #[cfg(feature = "parallel")]
 extern crate rayon;
@@ -7,29 +26,28 @@ extern crate rayon;
 mod rayon;
 
 use std::{
-    fs::File,
-    io::{BufWriter, Read, Write, stdin, stdout},
-    path::PathBuf,
+    fs::{File, Metadata},
+    io::{stdin, stdout, BufWriter, Read, Write},
+    path::Path,
     sync::{
-        Arc,
         atomic::{AtomicBool, Ordering},
+        Arc,
     },
     time::{Duration, Instant},
 };
 
-pub use indexmap::{IndexSet, indexset};
+pub use indexmap::{indexset, IndexSet};
 use log::{debug, info, trace, warn};
 use rayon::prelude::*;
 pub use rgb::{RGB16, RGBA8};
 
-#[cfg(feature = "zopfli")]
-pub use crate::deflate::ZopfliOptions;
 pub use crate::{
     colors::{BitDepth, ColorType},
-    deflate::Deflater,
+    deflate::Deflaters,
     error::PngError,
-    filters::{FilterStrategy, RowFilter},
+    filters::RowFilter,
     headers::StripChunks,
+    interlace::Interlacing,
     options::{InFile, Options, OutFile},
 };
 use crate::{
@@ -64,7 +82,6 @@ pub mod internal_tests {
 }
 
 pub type PngResult<T> = Result<T, PngError>;
-pub type OptimizationResult = PngResult<(usize, usize)>;
 
 #[derive(Debug)]
 /// A raw image definition which can be used to create an optimized png
@@ -87,7 +104,7 @@ impl RawImage {
         color_type: ColorType,
         bit_depth: BitDepth,
         data: Vec<u8>,
-    ) -> PngResult<Self> {
+    ) -> Result<Self, PngError> {
         // Validate bit depth
         let valid_depth = match color_type {
             ColorType::Grayscale { .. } => true,
@@ -113,7 +130,7 @@ impl RawImage {
                     height,
                     color_type,
                     bit_depth,
-                    interlaced: false,
+                    interlaced: Interlacing::None,
                 },
                 data,
             }),
@@ -129,7 +146,7 @@ impl RawImage {
     /// Add an ICC profile for the image
     pub fn add_icc_profile(&mut self, data: &[u8]) {
         // Compress with fastest compression level - will be recompressed during optimization
-        let deflater = Deflater::Libdeflater { compression: 1 };
+        let deflater = Deflaters::Libdeflater { compression: 1 };
         if let Ok(iccp) = make_iccp(data, deflater, None) {
             self.aux_chunks.push(iccp);
         }
@@ -153,7 +170,7 @@ impl RawImage {
 
         let mut png = PngData {
             raw: result.image,
-            idat_data: result.idat_data.unwrap(),
+            idat_data: result.data,
             aux_chunks,
             frames: Vec::new(),
         };
@@ -164,21 +181,44 @@ impl RawImage {
 }
 
 /// Perform optimization on the input file using the options provided
-///
-/// Returns the original and optimized file sizes
-pub fn optimize(input: &InFile, output: &OutFile, opts: &Options) -> OptimizationResult {
+pub fn optimize(input: &InFile, output: &OutFile, opts: &Options) -> PngResult<()> {
     // Read in the file and try to decode as PNG.
     info!("Processing: {input}");
 
     let deadline = Arc::new(Deadline::new(opts.timeout));
 
+    // grab metadata before even opening input file to preserve atime
+    let opt_metadata_preserved;
     let in_data = match *input {
-        InFile::Path(ref input_path) => PngData::read_file(input_path)?,
+        InFile::Path(ref input_path) => {
+            if matches!(
+                output,
+                OutFile::Path {
+                    preserve_attrs: true,
+                    ..
+                }
+            ) {
+                opt_metadata_preserved = input_path
+                    .metadata()
+                    .map_err(|err| {
+                        // Fail if metadata cannot be preserved
+                        PngError::new(&format!(
+                            "Unable to read metadata from input file {input_path:?}: {err}"
+                        ))
+                    })
+                    .map(Some)?;
+                trace!("preserving metadata: {opt_metadata_preserved:?}");
+            } else {
+                opt_metadata_preserved = None;
+            }
+            PngData::read_file(input_path)?
+        }
         InFile::StdIn => {
+            opt_metadata_preserved = None;
             let mut data = Vec::new();
             stdin()
                 .read_to_end(&mut data)
-                .map_err(|e| PngError::ReadFailed("stdin".into(), e))?;
+                .map_err(|e| PngError::new(&format!("Error reading stdin: {e}")))?;
             data
         }
     };
@@ -190,14 +230,14 @@ pub fn optimize(input: &InFile, output: &OutFile, opts: &Options) -> Optimizatio
 
     let in_length = in_data.len();
 
-    if is_fully_optimized(in_length, optimized_output.len(), opts) {
+    if is_fully_optimized(in_data.len(), optimized_output.len(), opts) {
         match (output, input) {
-            // If output path is None, it also means same as the input path
-            (OutFile::Path { path, .. }, InFile::Path(input_path))
-                if path.as_ref().is_none_or(|p| p == input_path) =>
+            // if p is None, it also means same as the input path
+            (OutFile::Path { path, .. }, InFile::Path(ref input_path))
+                if path.as_ref().map_or(true, |p| p == input_path) =>
             {
-                info!("Could not optimize further, no change written: {input}");
-                return Ok((in_length, in_length));
+                info!("{input}: Could not optimize further, no change written");
+                return Ok(());
             }
             _ => {
                 optimized_output = in_data;
@@ -221,65 +261,51 @@ pub fn optimize(input: &InFile, output: &OutFile, opts: &Options) -> Optimizatio
 
     match (output, input) {
         (OutFile::None, _) => {
-            info!("{savings}: Dry run, no output");
+            info!("{savings}: Running in pretend mode, no output");
         }
         (&OutFile::StdOut, _) | (&OutFile::Path { path: None, .. }, &InFile::StdIn) => {
             let mut buffer = BufWriter::new(stdout());
             buffer
                 .write_all(&optimized_output)
-                .map_err(|e| PngError::WriteFailed("stdout".into(), e))?;
-            info!("{savings}: stdout");
+                .map_err(|e| PngError::new(&format!("Unable to write to stdout: {e}")))?;
         }
-        (
-            OutFile::Path {
-                path,
-                preserve_attrs,
-            },
-            _,
-        ) => {
-            let input_metadata = if *preserve_attrs {
-                input.path().and_then(|in_path| {
-                    let meta = in_path.metadata();
-                    if let Err(e) = &meta {
-                        warn!("Unable to read metadata from {in_path:?}: {e}");
-                    }
-                    meta.ok()
-                })
-            } else {
-                None
-            };
-
+        (OutFile::Path { path, .. }, _) => {
             let output_path = path
                 .as_ref()
-                .map_or_else(|| input.path().unwrap(), PathBuf::as_path);
-            let out_file = File::create(output_path)
-                .map_err(|err| PngError::WriteFailed(output_path.display().to_string(), err))?;
+                .map(|p| p.as_path())
+                .unwrap_or_else(|| input.path().unwrap());
+            let out_file = File::create(output_path).map_err(|err| {
+                PngError::new(&format!(
+                    "Unable to write to file {}: {}",
+                    output_path.display(),
+                    err
+                ))
+            })?;
+            if let Some(metadata_input) = &opt_metadata_preserved {
+                copy_permissions(metadata_input, &out_file)?;
+            }
 
-            let mut buffer = BufWriter::new(&out_file);
+            let mut buffer = BufWriter::new(out_file);
             buffer
                 .write_all(&optimized_output)
                 // flush BufWriter so IO errors don't get swallowed silently on close() by drop!
                 .and_then(|()| buffer.flush())
-                .map_err(|e| PngError::WriteFailed(output_path.display().to_string(), e))?;
+                .map_err(|e| {
+                    PngError::new(&format!(
+                        "Unable to write to {}: {}",
+                        output_path.display(),
+                        e
+                    ))
+                })?;
             // force drop and thereby closing of file handle before modifying any timestamp
             std::mem::drop(buffer);
-
-            if let Some(metadata_input) = &input_metadata {
-                let set_time = metadata_input
-                    .modified()
-                    .and_then(|m| out_file.set_modified(m));
-                if let Err(e) = set_time {
-                    warn!("Unable to set modification time on {output_path:?}: {e}");
-                }
-                let set_perm = out_file.set_permissions(metadata_input.permissions());
-                if let Err(e) = set_perm {
-                    warn!("Unable to set permissions on {output_path:?}: {e}");
-                }
+            if let Some(metadata_input) = &opt_metadata_preserved {
+                copy_times(metadata_input, output_path)?;
             }
             info!("{}: {}", savings, output_path.display());
         }
     }
-    Ok((in_length, optimized_output.len()))
+    Ok(())
 }
 
 /// Perform optimization on the input file using the options provided, where the file is already
@@ -333,7 +359,7 @@ fn optimize_png(
     };
     if let Some(result) = optimize_raw(raw.clone(), &opts, deadline.clone(), max_size) {
         png.raw = result.image;
-        png.idat_data = result.idat_data.unwrap();
+        png.idat_data = result.data;
         recompress_frames(png, &opts, deadline, result.filter)?;
         postprocess_chunks(&mut png.aux_chunks, &png.raw.ihdr, &raw.ihdr);
     }
@@ -369,10 +395,8 @@ fn optimize_png(
         );
     }
 
-    if opts.interlace == Some(true) && !png.raw.ihdr.interlaced {
-        warn!(
-            "Interlacing was not enabled as it would result in a larger file. To override this, use `--force`."
-        );
+    if opts.interlace == Some(Interlacing::Adam7) && png.raw.ihdr.interlaced != Interlacing::Adam7 {
+        warn!("Interlacing was not enabled as it would result in a larger file. To override this, use `--force`.");
     }
 
     #[cfg(feature = "sanity-checks")]
@@ -394,19 +418,19 @@ fn optimize_raw(
     // 8 is a little slower but not noticeably when used only for reductions (o3 and higher)
     // 9 is not appreciably better than 8
     // 10 and higher are quite slow - good for filters but only good for reductions if matching the main zc level
-    let compression = match opts.deflater {
-        Deflater::Libdeflater { compression } => {
+    let compression = match opts.deflate {
+        Deflaters::Libdeflater { compression } => {
             if opts.fast_evaluation { 7 } else { 8 }.min(compression)
         }
         _ => 8,
     };
-    let eval_deflater = Deflater::Libdeflater { compression };
+    let eval_deflater = Deflaters::Libdeflater { compression };
     // If only one filter is selected, use this for evaluations
-    let eval_filters = if opts.filters.len() == 1 {
-        opts.filters.clone()
+    let eval_filters = if opts.filter.len() == 1 {
+        opts.filter.clone()
     } else {
         // None and Bigrams work well together, especially for alpha reductions
-        indexset! {FilterStrategy::NONE, FilterStrategy::Bigrams}
+        indexset! {RowFilter::None, RowFilter::Bigrams}
     };
     // This will collect all versions of images and pick one that compresses best
     let eval = Evaluator::new(
@@ -414,7 +438,7 @@ fn optimize_raw(
         eval_filters.clone(),
         eval_deflater,
         false,
-        opts.deflater == eval_deflater,
+        opts.deflate == eval_deflater,
     );
     let mut new_image = perform_reductions(image.clone(), opts, &deadline, &eval);
     let eval_result = eval.get_best_candidate();
@@ -431,23 +455,23 @@ fn optimize_raw(
 
     let (result, deflater) = if opts.idat_recoding || reduction_occurred {
         let result = perform_trials(
-            new_image,
+            new_image.clone(),
             opts,
-            deadline,
+            deadline.clone(),
             max_size,
             eval_result,
             eval_filters,
             eval_deflater,
         );
-        (result?, opts.deflater)
+        (result?, opts.deflate)
     } else {
         // If idat_recoding is off and reductions were attempted but ended up choosing the baseline,
         // we should still check if the evaluator compressed the baseline smaller than the original.
         (eval_result?, eval_deflater)
     };
 
-    if result.idat_data.is_some()
-        && max_size.is_none_or(|max_size| result.estimated_output_size < max_size)
+    if result.data_is_compressed
+        && max_size.map_or(true, |max_size| result.estimated_output_size < max_size)
     {
         debug!("Found better result:");
         debug!("    {}, f = {}", deflater, result.filter);
@@ -463,27 +487,27 @@ fn perform_trials(
     deadline: Arc<Deadline>,
     max_size: Option<usize>,
     mut eval_result: Option<Candidate>,
-    eval_filters: IndexSet<FilterStrategy>,
-    eval_deflater: Deflater,
+    eval_filters: IndexSet<RowFilter>,
+    eval_deflater: Deflaters,
 ) -> Option<Candidate> {
-    let mut filters = opts.filters.clone();
+    let mut filters = opts.filter.clone();
     let fast_eval = opts.fast_evaluation && (filters.len() > 1 || eval_result.is_some());
     if fast_eval {
         // Perform a fast evaluation of selected filters followed by a single main compression trial
 
         if eval_result.is_some() {
             // Some filters have already been evaluated, we don't need to try them again
-            filters = filters.difference(&eval_filters).cloned().collect();
+            filters = filters.difference(&eval_filters).copied().collect();
         }
 
         if !filters.is_empty() {
             trace!("Evaluating {} filters", filters.len());
             let eval = Evaluator::new(
-                deadline,
+                deadline.clone(),
                 filters,
                 eval_deflater,
                 opts.optimize_alpha,
-                opts.deflater == eval_deflater,
+                opts.deflate == eval_deflater,
             );
             if let Some(result) = &eval_result {
                 eval.set_best_size(result.estimated_output_size);
@@ -497,21 +521,21 @@ fn perform_trials(
         // We should have a result here - fail if not (e.g. deadline passed)
         let mut result = eval_result?;
 
-        if result.idat_data.is_none() {
+        if !result.data_is_compressed {
             // Compress with the main deflater
-            debug!("Trying filter {} with {}", result.filter, opts.deflater);
-            let (data, _) = image.filter_image(result.filter_used.clone(), opts.optimize_alpha);
-            match opts.deflater.deflate(&data, max_size) {
+            debug!("Trying filter {} with {}", result.filter, opts.deflate);
+            match opts.deflate.deflate(&result.data, max_size) {
                 Ok(idat_data) => {
                     result.estimated_output_size = result.image.estimated_output_size(&idat_data);
-                    result.idat_data = Some(idat_data);
+                    result.data = idat_data;
+                    result.data_is_compressed = true;
                     trace!("{} bytes", result.estimated_output_size);
                 }
                 Err(PngError::DeflatedDataTooLong(bytes)) => {
                     trace!(">{bytes} bytes");
                 }
                 Err(_) => (),
-            }
+            };
         }
         return Some(result);
     }
@@ -522,15 +546,15 @@ fn perform_trials(
         // Pick a filter automatically
         if image.ihdr.bit_depth as u8 >= 8 {
             // Bigrams is the best all-rounder when there's at least one byte per pixel
-            filters.insert(FilterStrategy::Bigrams);
+            filters.insert(RowFilter::Bigrams);
         } else {
             // Otherwise delta filters generally don't work well, so just stick with None
-            filters.insert(FilterStrategy::NONE);
+            filters.insert(RowFilter::None);
         }
     }
 
-    debug!("Trying {} filters with {}", filters.len(), opts.deflater);
-    let eval = Evaluator::new(deadline, filters, opts.deflater, opts.optimize_alpha, true);
+    debug!("Trying {} filters with {}", filters.len(), opts.deflate);
+    let eval = Evaluator::new(deadline, filters, opts.deflate, opts.optimize_alpha, true);
     if let Some(max_size) = max_size {
         eval.set_best_size(max_size);
     }
@@ -590,14 +614,9 @@ impl Deadline {
 
 /// Display the format of the image data
 fn report_format(prefix: &str, png: &PngImage) {
-    let interlaced = if png.ihdr.interlaced {
-        "interlaced"
-    } else {
-        "non-interlaced"
-    };
     debug!(
         "{}{}-bit {}, {}",
-        prefix, png.ihdr.bit_depth, png.ihdr.color_type, interlaced
+        prefix, png.ihdr.bit_depth, png.ihdr.color_type, png.ihdr.interlaced
     );
 }
 
@@ -606,13 +625,11 @@ fn recompress_frames(
     png: &mut PngData,
     opts: &Options,
     deadline: Arc<Deadline>,
-    filter: FilterStrategy,
+    filter: RowFilter,
 ) -> PngResult<()> {
     if !opts.idat_recoding || png.frames.is_empty() {
         return Ok(());
     }
-    // Ensure we don't try to recompress frames with a predefined filter
-    debug_assert!(!matches!(filter, FilterStrategy::Predefined { .. }));
     png.frames
         .par_iter_mut()
         .with_max_len(1)
@@ -625,9 +642,9 @@ fn recompress_frames(
             ihdr.width = frame.width;
             ihdr.height = frame.height;
             let image = PngImage::new(ihdr, &frame.data)?;
-            let (filtered, _) = image.filter_image(filter.clone(), opts.optimize_alpha);
+            let filtered = image.filter_image(filter, opts.optimize_alpha);
             let max_size = Some(frame.data.len() - 1);
-            if let Ok(data) = opts.deflater.deflate(&filtered, max_size) {
+            if let Ok(data) = opts.deflate.deflate(&filtered, max_size) {
                 debug!(
                     "Recompressed fdAT #{:<2}: {} ({} bytes decrease)",
                     i,
@@ -641,6 +658,33 @@ fn recompress_frames(
 }
 
 /// Check if an image was already optimized prior to oxipng's operations
-const fn is_fully_optimized(original_size: usize, optimized_size: usize, opts: &Options) -> bool {
+fn is_fully_optimized(original_size: usize, optimized_size: usize, opts: &Options) -> bool {
     original_size <= optimized_size && !opts.force
 }
+
+fn copy_permissions(metadata_input: &Metadata, out_file: &File) -> PngResult<()> {
+    out_file
+        .set_permissions(metadata_input.permissions())
+        .map_err(|err_io| {
+            PngError::new(&format!(
+                "unable to set permissions for output file: {err_io}"
+            ))
+        })
+}
+
+#[cfg(not(feature = "filetime"))]
+fn copy_times(_: &Metadata, _: &Path) -> PngResult<()> {
+    Ok(())
+}
+
+#[cfg(feature = "filetime")]
+fn copy_times(input_path_meta: &Metadata, out_path: &Path) -> PngResult<()> {
+    let atime = filetime::FileTime::from_last_access_time(input_path_meta);
+    let mtime = filetime::FileTime::from_last_modification_time(input_path_meta);
+    trace!("attempting to set file times: atime: {atime:?}, mtime: {mtime:?}");
+    filetime::set_file_times(out_path, atime, mtime).map_err(|err_io| {
+        PngError::new(&format!(
+            "unable to set file times on {out_path:?}: {err_io}"
+        ))
+    })
+}

src/main.rs

@@ -1,27 +1,32 @@
+#![warn(trivial_casts, trivial_numeric_casts, unused_import_braces)]
+#![deny(missing_debug_implementations, missing_copy_implementations)]
+#![warn(clippy::expl_impl_clone_on_copy)]
+#![warn(clippy::float_cmp_const)]
+#![warn(clippy::linkedlist)]
+#![warn(clippy::map_flatten)]
+#![warn(clippy::match_same_arms)]
+#![warn(clippy::mem_forget)]
+#![warn(clippy::mut_mut)]
+#![warn(clippy::mutex_integer)]
+#![warn(clippy::needless_continue)]
+#![warn(clippy::path_buf_push_overwrite)]
+#![warn(clippy::range_plus_one)]
+#![allow(clippy::cognitive_complexity)]
+
 #[cfg(not(feature = "parallel"))]
 mod rayon;
 
 #[cfg(feature = "zopfli")]
-use std::num::NonZeroU64;
+use std::num::NonZeroU8;
 use std::{
-    ffi::{OsStr, OsString},
-    fs::DirBuilder,
-    io::{IsTerminal, Write, stdout},
-    path::PathBuf,
-    process::ExitCode,
-    sync::atomic::{AtomicUsize, Ordering::AcqRel},
-    time::Duration,
+    ffi::OsString, fs::DirBuilder, io::Write, path::PathBuf, process::ExitCode, time::Duration,
 };
 
 use clap::ArgMatches;
 mod cli;
 use indexmap::IndexSet;
-use log::{Level, LevelFilter, error, warn};
-#[cfg(feature = "zopfli")]
-use oxipng::ZopfliOptions;
-use oxipng::{
-    Deflater, FilterStrategy, InFile, OptimizationResult, Options, OutFile, PngError, StripChunks,
-};
+use log::{error, warn, Level, LevelFilter};
+use oxipng::{Deflaters, InFile, Options, OutFile, PngError, RowFilter, StripChunks};
 use rayon::prelude::*;
 
 use crate::cli::DISPLAY_CHUNKS;
@@ -31,14 +36,15 @@ fn main() -> ExitCode {
         // Set the value parser for filters which isn't appropriate to do in the build_command function
         .mut_arg("filters", |arg| {
             arg.value_parser(|x: &str| {
-                parse_numeric_range_opts(x, 0, 9).map_err(|_| "Invalid option for filters")
+                parse_numeric_range_opts(x, 0, RowFilter::LAST)
+                    .map_err(|_| "Invalid option for filters")
             })
         })
         .after_help("Run `oxipng --help` to see full details of all options")
         .after_long_help("")
         .get_matches_from(std::env::args());
 
-    let (mut out_file, out_dir, opts) = match parse_opts_into_struct(&matches) {
+    let (out_file, out_dir, opts) = match parse_opts_into_struct(&matches) {
         Ok(x) => x,
         Err(x) => {
             error!("{x}");
@@ -46,128 +52,51 @@ fn main() -> ExitCode {
         }
     };
 
-    // Determine input and output
-    let file_args = matches.get_many::<PathBuf>("files").unwrap().cloned();
-    #[cfg(windows)]
-    let inputs: Vec<_> = file_args.flat_map(apply_glob_pattern).collect();
-    #[cfg(not(windows))]
-    let inputs: Vec<_> = file_args.collect();
-    let using_stdin = inputs.len() == 1 && inputs[0].to_str() == Some("-");
-    if using_stdin && out_dir.is_some() {
-        error!("Cannot use --dir when reading from stdin.");
-        return ExitCode::FAILURE;
-    }
-    if using_stdin && matches!(out_file, OutFile::Path { path: None, .. }) {
-        out_file = OutFile::StdOut;
-    }
-    let using_stdout = matches!(out_file, OutFile::StdOut);
-    let json = matches.get_flag("json");
-    if using_stdout && json {
-        error!("Cannot use --json when writing to stdout.");
-        return ExitCode::FAILURE;
-    }
+    let files = collect_files(
+        #[cfg(windows)]
+        matches
+            .get_many::<PathBuf>("files")
+            .unwrap()
+            .cloned()
+            .flat_map(apply_glob_pattern)
+            .collect(),
+        #[cfg(not(windows))]
+        matches
+            .get_many::<PathBuf>("files")
+            .unwrap()
+            .cloned()
+            .collect(),
+        &out_dir,
+        &out_file,
+        matches.get_flag("recursive"),
+        true,
+    );
 
-    let files = if using_stdin {
-        vec![(InFile::StdIn, out_file)]
+    let parallel_files = matches.get_flag("parallel-files");
+    let summary = if parallel_files {
+        files
+            .into_par_iter()
+            .map(|(input, output)| process_file(&input, &output, &opts))
+            .min()
     } else {
-        collect_files(
-            inputs,
-            &out_dir,
-            &out_file,
-            matches.get_flag("recursive"),
-            true,
-        )
+        files
+            .into_iter()
+            .map(|(input, output)| process_file(&input, &output, &opts))
+            .min()
     };
 
-    let is_verbose = matches.get_count("verbose") > 0;
-    let print_summary = !matches.get_flag("quiet") && !using_stdout;
-    let print_progress = print_summary && !is_verbose && stdout().is_terminal();
-    let total_files = files.len();
-    let num_processed = AtomicUsize::new(0);
-    if print_progress {
-        print!("Files processed: 0/{}...", total_files);
-        stdout().flush().ok();
+    match summary.unwrap_or(OptimizationResult::Skipped) {
+        OptimizationResult::Ok => ExitCode::SUCCESS,
+        OptimizationResult::Failed => ExitCode::FAILURE,
+        OptimizationResult::Skipped => ExitCode::from(3),
     }
-    let process = |(input, output): &(InFile, OutFile)| {
-        let result = process_file(input, output, &opts);
-        if print_progress && matches!(result, OptimizationResult::Ok(_)) {
-            let value = num_processed.fetch_add(1, AcqRel) + 1;
-            print!("\rFiles processed: {}/{}...", value, total_files);
-            stdout().flush().ok();
-        }
-        result
-    };
-    let results: Vec<OptimizationResult> = if matches.get_flag("parallel-files") {
-        files.par_iter().map(process).collect()
-    } else {
-        files.iter().map(process).collect()
-    };
+}
 
-    // Collect stats
-    let mut num_succeeded = 0;
-    let mut num_not_optimized = 0;
-    let mut num_failed = 0;
-    let mut total_in: i64 = 0;
-    let mut total_out: i64 = 0;
-    for result in &results {
-        match result {
-            Ok((insize, outsize)) => {
-                num_succeeded += 1;
-                total_in += *insize as i64;
-                total_out += *outsize as i64;
-                if !opts.force && insize == outsize {
-                    num_not_optimized += 1;
-                }
-            }
-            Err(PngError::C2PAMetadataPreventsChanges | PngError::InflatedDataTooLong(_)) => {}
-            Err(_) => num_failed += 1,
-        }
-    }
-
-    // Print results
-    if json {
-        json_output(&files, &results);
-    } else if print_summary {
-        let in_bytes = format_bytes(total_in, true);
-        let out_bytes = format_bytes(total_out, true);
-        let saved = total_in - total_out;
-        let saved_bytes = format_bytes(saved, false);
-        let percent = if total_in > 0 {
-            saved as f64 / total_in as f64 * 100_f64
-        } else {
-            0_f64
-        };
-        if is_verbose {
-            println!("--------------------");
-        }
-        println!("\rFiles processed: {num_succeeded}/{total_files}   ");
-        println!("Input size: {}", in_bytes);
-        println!("Output size: {}", out_bytes);
-        println!("Total saved: {} ({:.2}%)", saved_bytes, percent);
-        if num_not_optimized == 1 {
-            println!("({num_not_optimized} file could not be optimized further)");
-        } else if num_not_optimized > 0 {
-            println!("({num_not_optimized} files could not be optimized further)");
-        }
-        if matches.get_flag("dry-run") {
-            println!("Dry run, no changes saved");
-        }
-    }
-
-    // For optimizing single files, this will return the correct exit code always.
-    // For recursive optimization, the correct choice is a bit subjective.
-    // We're choosing to return a 0 exit code if ANY file in the set
-    // runs correctly.
-    // The reason for this is that recursion may pick up files that are not
-    // PNG files, and return an error for them.
-    // We don't really want to return an error code for those files.
-    if num_succeeded > 0 {
-        ExitCode::SUCCESS
-    } else if num_failed > 0 {
-        ExitCode::FAILURE
-    } else {
-        ExitCode::from(3)
-    }
+#[derive(Eq, PartialEq, Ord, PartialOrd)]
+enum OptimizationResult {
+    Ok,
+    Failed,
+    Skipped,
 }
 
 fn collect_files(
@@ -178,8 +107,10 @@ fn collect_files(
     top_level: bool, //explicitly specify files
 ) -> Vec<(InFile, OutFile)> {
     let mut in_out_pairs = Vec::new();
+    let allow_stdin = top_level && files.len() == 1;
     for input in files {
-        if input.is_dir() {
+        let using_stdin = allow_stdin && input.to_str() == Some("-");
+        if !using_stdin && input.is_dir() {
             if recursive {
                 match input.read_dir() {
                     Ok(dir) => {
@@ -195,16 +126,7 @@ fn collect_files(
                 warn!("{} is a directory, skipping", input.display());
             }
             continue;
-        }
-
-        // Skip non png files if not given on top level
-        if !top_level && {
-            let extension = input.extension().map(OsStr::to_ascii_lowercase);
-            extension != Some(OsString::from("png")) && extension != Some(OsString::from("apng"))
-        } {
-            continue;
-        }
-
+        };
         let out_file =
             if let (Some(out_dir), &OutFile::Path { preserve_attrs, .. }) = (out_dir, out_file) {
                 let path = Some(out_dir.join(input.file_name().unwrap()));
@@ -215,7 +137,19 @@ fn collect_files(
             } else {
                 (*out_file).clone()
             };
-        let in_file = InFile::Path(input);
+        let in_file = if using_stdin {
+            InFile::StdIn
+        } else {
+            // Skip non png files if not given on top level
+            if !top_level && {
+                let extension = input.extension().map(|f| f.to_ascii_lowercase());
+                extension != Some(OsString::from("png"))
+                    && extension != Some(OsString::from("apng"))
+            } {
+                continue;
+            }
+            InFile::Path(input)
+        };
         in_out_pairs.push((in_file, out_file));
     }
     in_out_pairs
@@ -240,9 +174,8 @@ fn parse_opts_into_struct(
 ) -> Result<(OutFile, Option<PathBuf>, Options), String> {
     let log_level = match matches.get_count("verbose") {
         _ if matches.get_flag("quiet") => LevelFilter::Off,
-        0 => LevelFilter::Warn,
-        1 => LevelFilter::Info,
-        2 => LevelFilter::Debug,
+        0 => LevelFilter::Info,
+        1 => LevelFilter::Debug,
         _ => LevelFilter::Trace,
     };
     env_logger::builder()
@@ -251,8 +184,7 @@ fn parse_opts_into_struct(
             match record.level() {
                 Level::Error | Level::Warn => {
                     let style = buf.default_level_style(record.level());
-                    // Prepend carriage return to clear progress line
-                    writeln!(buf, "\r{style}{}{style:#}", record.args())
+                    writeln!(buf, "{style}{}{style:#}", record.args())
                 }
                 // Leave info, debug and trace unstyled
                 _ => writeln!(buf, "{}", record.args()),
@@ -266,39 +198,11 @@ fn parse_opts_into_struct(
         Some(level) => Options::from_preset(level.parse::<u8>().unwrap()),
     };
 
-    // Get custom brute settings and rebuild the filter set to apply them
-    let mut brute_lines = matches.get_one::<usize>("brute-lines").copied();
-    let mut brute_level = matches.get_one::<i64>("brute-level").map(|x| *x as u8);
-    let mut new_filters = IndexSet::new();
-    for mut f in opts.filters.drain(..) {
-        if let FilterStrategy::Brute { num_lines, level } = &mut f {
-            *num_lines = brute_lines.unwrap_or(*num_lines);
-            *level = brute_level.unwrap_or(*level);
-            // If custom settings were not given, we still need to retain the default values
-            // from the preset so we can re-apply them if the filters are overridden below
-            brute_lines = Some(*num_lines);
-            brute_level = Some(*level);
-        }
-        new_filters.insert(f);
-    }
-    opts.filters = new_filters;
-
     if let Some(x) = matches.get_one::<IndexSet<u8>>("filters") {
-        opts.filters = x
-            .iter()
-            .map(|&f| match f {
-                0..=4 => FilterStrategy::Basic(f.try_into().unwrap()),
-                5 => FilterStrategy::MinSum,
-                6 => FilterStrategy::Entropy,
-                7 => FilterStrategy::Bigrams,
-                8 => FilterStrategy::BigEnt,
-                9 => FilterStrategy::Brute {
-                    num_lines: brute_lines.unwrap_or(3),
-                    level: brute_level.unwrap_or(1),
-                },
-                _ => unreachable!(),
-            })
-            .collect();
+        opts.filter.clear();
+        for &f in x {
+            opts.filter.insert(f.try_into().unwrap());
+        }
     }
 
     if let Some(&num) = matches.get_one::<u64>("timeout") {
@@ -310,7 +214,7 @@ fn parse_opts_into_struct(
             match DirBuilder::new().recursive(true).create(path) {
                 Ok(()) => (),
                 Err(x) => return Err(format!("Could not create output directory {x}")),
-            }
+            };
         } else if !path.is_dir() {
             return Err(format!(
                 "{} is an existing file (not a directory), cannot create directory",
@@ -322,7 +226,7 @@ fn parse_opts_into_struct(
         None
     };
 
-    let out_file = if matches.get_flag("dry-run") {
+    let out_file = if matches.get_flag("pretend") {
         OutFile::None
     } else if matches.get_flag("stdout") {
         OutFile::StdOut
@@ -346,8 +250,6 @@ fn parse_opts_into_struct(
 
     opts.fix_errors = matches.get_flag("fix");
 
-    opts.max_decompressed_size = matches.get_one::<u64>("max-size").map(|&x| x as usize);
-
     opts.bit_depth_reduction = !matches.get_flag("no-bit-reduction");
 
     opts.color_type_reduction = !matches.get_flag("no-color-reduction");
@@ -367,10 +269,10 @@ fn parse_opts_into_struct(
     opts.idat_recoding = !matches.get_flag("no-recoding");
 
     if let Some(x) = matches.get_one::<String>("interlace") {
-        opts.interlace = match x.as_str() {
-            "off" | "0" => Some(false),
-            "on" | "1" => Some(true),
-            _ => None, // keep
+        opts.interlace = if x == "keep" {
+            None
+        } else {
+            x.parse::<u8>().unwrap().try_into().ok()
         };
     }
 
@@ -426,28 +328,13 @@ fn parse_opts_into_struct(
 
     #[cfg(feature = "zopfli")]
     if matches.get_flag("zopfli") {
-        let iteration_count = *matches.get_one::<NonZeroU64>("iterations").unwrap();
-        let iterations_without_improvement = *matches
-            .get_one::<NonZeroU64>("iterations-without-improvement")
-            .unwrap_or(&NonZeroU64::MAX);
-
-        if iterations_without_improvement > iteration_count
-            && iterations_without_improvement != NonZeroU64::MAX
-        {
-            warn!(
-                "--ziwi ({}) is higher than --zi ({}) and will never be reached.",
-                iterations_without_improvement, iteration_count
-            );
-        }
-
-        opts.deflater = Deflater::Zopfli(ZopfliOptions {
-            iteration_count,
-            iterations_without_improvement,
-            ..Default::default()
-        });
+        let iterations = *matches.get_one::<i64>("iterations").unwrap();
+        opts.deflate = Deflaters::Zopfli {
+            iterations: NonZeroU8::new(iterations as u8).unwrap(),
+        };
     }
-    if let (Deflater::Libdeflater { compression }, Some(x)) =
-        (&mut opts.deflater, matches.get_one::<i64>("compression"))
+    if let (Deflaters::Libdeflater { compression }, Some(x)) =
+        (&mut opts.deflate, matches.get_one::<i64>("compression"))
     {
         *compression = *x as u8;
     }
@@ -524,131 +411,22 @@ fn parse_numeric_range_opts(
 }
 
 fn process_file(input: &InFile, output: &OutFile, opts: &Options) -> OptimizationResult {
-    if let (Some(max_size), InFile::Path(path)) = (opts.max_decompressed_size, input) {
-        if path.metadata().is_ok_and(|m| m.len() > max_size as u64) {
-            warn!("{input}: Skipped: File exceeds the maximum size ({max_size} bytes)");
-            return Err(PngError::InflatedDataTooLong(max_size));
-        }
-    }
-
-    let result = oxipng::optimize(input, output, opts);
-    match &result {
-        Ok(_) => {}
-        Err(e @ PngError::C2PAMetadataPreventsChanges | e @ PngError::InflatedDataTooLong(_)) => {
-            warn!("{input}: Skipped: {e}");
+    match oxipng::optimize(input, output, opts) {
+        // For optimizing single files, this will return the correct exit code always.
+        // For recursive optimization, the correct choice is a bit subjective.
+        // We're choosing to return a 0 exit code if ANY file in the set
+        // runs correctly.
+        // The reason for this is that recursion may pick up files that are not
+        // PNG files, and return an error for them.
+        // We don't really want to return an error code for those files.
+        Ok(_) => OptimizationResult::Ok,
+        Err(e @ PngError::C2PAMetadataPreventsChanges) => {
+            warn!("{input}: {e}");
+            OptimizationResult::Skipped
         }
         Err(e) => {
             error!("{input}: {e}");
+            OptimizationResult::Failed
         }
     }
-    result
-}
-
-/// Write optimization results as json.
-/// ```
-/// {
-///   "results": [
-///     {
-///       "input": string,
-///       "status": "success",
-///       "output": string|null,
-///       "insize": number,
-///       "outsize": number
-///     },
-///     {
-///       "input": string,
-///       "status": "error",
-///       "error": string
-///     }
-///   ]
-/// }
-/// ```
-fn json_output(files: &[(InFile, OutFile)], results: &[OptimizationResult]) {
-    print!(r#"{{"results":["#);
-    let mut first = true;
-    results
-        .iter()
-        .zip(files)
-        .for_each(|(result, (input, output))| {
-            if !first {
-                print!(",");
-            }
-            print!(r#"{{"input":"{}","#, json_escape(&input.to_string()));
-            match result {
-                Ok((insize, outsize)) => {
-                    let outpath = match output {
-                        OutFile::None => "null".to_owned(),
-                        OutFile::Path { path: None, .. } => {
-                            format!(r#""{}""#, json_escape(&input.to_string()))
-                        }
-                        OutFile::Path { path: Some(p), .. } => {
-                            format!(r#""{}""#, json_escape(&p.display().to_string()))
-                        }
-                        OutFile::StdOut => unreachable!(),
-                    };
-                    print!(
-                        r#""status":"success","output":{},"insize":{},"outsize":{}}}"#,
-                        outpath, insize, outsize
-                    );
-                }
-                Err(e) => {
-                    print!(
-                        r#""status":"error","error":"{}"}}"#,
-                        json_escape(&e.to_string())
-                    );
-                }
-            }
-            first = false;
-        });
-    print!("]}}");
-}
-
-fn json_escape(string: &str) -> String {
-    string
-        .replace("\\", "\\\\")
-        .replace("\"", "\\\"")
-        .replace("\n", "\\n")
-        .replace("\t", "\\t")
-        .replace("\r", "\\r")
-        .replace("\x08", "\\b")
-        .replace("\x0c", "\\f")
-}
-
-/// Format byte counts as IEC units to 3 significant figures.
-fn format_bytes(count: i64, include_raw: bool) -> String {
-    const K: i64 = 1 << 10;
-    const M: i64 = 1 << 20;
-    const G: i64 = 1 << 30;
-    fn format_3sf(value: f64) -> String {
-        match value.abs() {
-            ..9.995 => format!("{:.2}", value),
-            9.995..99.95 => format!("{:.1}", value),
-            _ => format!("{:.0}", value),
-        }
-    }
-    let formatted = match count.abs() {
-        ..K => format!("{} bytes", count),
-        K..M => format!("{} KiB", format_3sf(count as f64 / K as f64)),
-        M..G => format!("{} MiB", format_3sf(count as f64 / M as f64)),
-        _ => format!("{} GiB", format_3sf(count as f64 / G as f64)),
-    };
-    if include_raw && count.abs() >= K {
-        format!("{} ({} bytes)", formatted, count)
-    } else {
-        formatted
-    }
-}
-
-#[cfg(test)]
-mod tests {
-    use super::format_bytes;
-
-    #[test]
-    fn test_format_bytes() {
-        assert_eq!(format_bytes(1023, false), "1023 bytes");
-        assert_eq!(format_bytes(800_000, false), "781 KiB");
-        assert_eq!(format_bytes(12_500_000, false), "11.9 MiB");
-        assert_eq!(format_bytes(2_000_000_000, false), "1.86 GiB");
-        assert_eq!(format_bytes(-1024, false), "-1.00 KiB");
-    }
 }

src/options.rs

@@ -4,10 +4,10 @@ use std::{
     time::Duration,
 };
 
-use indexmap::{IndexSet, indexset};
+use indexmap::{indexset, IndexSet};
 use log::warn;
 
-use crate::{deflate::Deflater, filters::FilterStrategy, headers::StripChunks};
+use crate::{deflate::Deflaters, filters::RowFilter, headers::StripChunks, interlace::Interlacing};
 
 /// Write destination for [`optimize`][crate::optimize].
 /// You can use [`optimize_from_memory`](crate::optimize_from_memory) to avoid external I/O.
@@ -32,8 +32,8 @@ impl OutFile {
     ///
     /// This is a convenience method for `OutFile::Path { path: Some(path), preserve_attrs: false }`.
     #[must_use]
-    pub const fn from_path(path: PathBuf) -> Self {
-        Self::Path {
+    pub fn from_path(path: PathBuf) -> Self {
+        OutFile::Path {
             path: Some(path),
             preserve_attrs: false,
         }
@@ -94,17 +94,19 @@ pub struct Options {
     ///
     /// Default: `false`
     pub force: bool,
-    /// Which `FilterStrategy` to try on the file
+    /// Which `RowFilters` to try on the file
     ///
     /// Default: `None,Sub,Entropy,Bigrams`
-    pub filters: IndexSet<FilterStrategy>,
-    /// Whether to change the interlacing of the file.
+    pub filter: IndexSet<RowFilter>,
+    /// Whether to change the interlacing type of the file.
     ///
-    /// - `None` will not change the current interlacing.
-    /// - `Some(x)` will turn interlacing on or off.
+    /// These are the interlacing types avaliable:
+    /// - `None` will not change the current interlacing type.
+    /// - `Some(x)` will change the file to interlacing mode `x`.
+    ///   See [`Interlacing`] for the possible interlacing types.
     ///
-    /// Default: `Some(false)`
-    pub interlace: Option<bool>,
+    /// Default: `Some(Interlacing::None)`
+    pub interlace: Option<Interlacing>,
     /// Whether to allow transparent pixels to be altered to improve compression.
     ///
     /// Default: `false`
@@ -144,7 +146,7 @@ pub struct Options {
     #[cfg_attr(feature = "zopfli", doc = "(e.g. Zopfli)")]
     ///
     /// Default: `Libdeflater`
-    pub deflater: Deflater,
+    pub deflate: Deflaters,
     /// Whether to use fast evaluation to pick the best filter
     ///
     /// Default: `true`
@@ -154,11 +156,6 @@ pub struct Options {
     ///
     /// Default: `None`
     pub timeout: Option<Duration>,
-    /// Maximum decompressed size of the input IDAT.
-    /// If decompression would exceed this size, it will be rejected.
-    ///
-    /// Default: `None`
-    pub max_decompressed_size: Option<usize>,
 }
 
 impl Options {
@@ -188,88 +185,59 @@ impl Options {
     // The following methods make assumptions that they are operating
     // on an `Options` struct generated by the `default` method.
     fn apply_preset_0(mut self) -> Self {
-        self.filters.clear();
-        self.deflater = Deflater::Libdeflater { compression: 5 };
+        self.filter.clear();
+        if let Deflaters::Libdeflater { compression } = &mut self.deflate {
+            *compression = 5;
+        }
         self
     }
 
     fn apply_preset_1(mut self) -> Self {
-        self.filters.clear();
-        self.deflater = Deflater::Libdeflater { compression: 10 };
+        self.filter.clear();
+        if let Deflaters::Libdeflater { compression } = &mut self.deflate {
+            *compression = 10;
+        }
         self
     }
 
-    const fn apply_preset_2(self) -> Self {
+    fn apply_preset_2(self) -> Self {
         self
     }
 
     fn apply_preset_3(mut self) -> Self {
         self.fast_evaluation = false;
-        self.filters = indexset! {
-            FilterStrategy::NONE,
-            FilterStrategy::Bigrams,
-            FilterStrategy::BigEnt,
-            FilterStrategy::Brute {
-                num_lines: 3,
-                level: 1,
-            },
+        self.filter = indexset! {
+            RowFilter::None,
+            RowFilter::Bigrams,
+            RowFilter::BigEnt,
+            RowFilter::Brute
         };
         self
     }
 
     fn apply_preset_4(mut self) -> Self {
-        self.fast_evaluation = false;
-        self.filters = indexset! {
-            FilterStrategy::NONE,
-            FilterStrategy::Bigrams,
-            FilterStrategy::BigEnt,
-            FilterStrategy::Brute {
-                num_lines: 4,
-                level: 1,
-            },
-        };
-        self.deflater = Deflater::Libdeflater { compression: 12 };
-        self
+        if let Deflaters::Libdeflater { compression } = &mut self.deflate {
+            *compression = 12;
+        }
+        self.apply_preset_3()
     }
 
     fn apply_preset_5(mut self) -> Self {
         self.fast_evaluation = false;
-        self.filters = indexset! {
-            FilterStrategy::NONE,
-            FilterStrategy::SUB,
-            FilterStrategy::UP,
-            FilterStrategy::MinSum,
-            FilterStrategy::Entropy,
-            FilterStrategy::Bigrams,
-            FilterStrategy::BigEnt,
-            FilterStrategy::Brute {
-                num_lines: 4,
-                level: 4,
-            },
-        };
-        self.deflater = Deflater::Libdeflater { compression: 12 };
+        self.filter.insert(RowFilter::Up);
+        self.filter.insert(RowFilter::MinSum);
+        self.filter.insert(RowFilter::BigEnt);
+        self.filter.insert(RowFilter::Brute);
+        if let Deflaters::Libdeflater { compression } = &mut self.deflate {
+            *compression = 12;
+        }
         self
     }
 
     fn apply_preset_6(mut self) -> Self {
-        self.fast_evaluation = false;
-        self.filters = indexset! {
-            FilterStrategy::NONE,
-            FilterStrategy::SUB,
-            FilterStrategy::UP,
-            FilterStrategy::AVERAGE,
-            FilterStrategy::PAETH,
-            FilterStrategy::MinSum,
-            FilterStrategy::Entropy,
-            FilterStrategy::Bigrams,
-            FilterStrategy::BigEnt,
-            FilterStrategy::Brute {
-                num_lines: 8,
-                level: 5,
-            },
-        };
-        self.deflater = Deflater::Libdeflater { compression: 12 };
-        self
+        self.filter.insert(RowFilter::Average);
+        self.filter.insert(RowFilter::Paeth);
+        self.apply_preset_5()
     }
 }
 
@@ -279,13 +247,8 @@ impl Default for Options {
         Self {
             fix_errors: false,
             force: false,
-            filters: indexset! {
-                FilterStrategy::NONE,
-                FilterStrategy::SUB,
-                FilterStrategy::Entropy,
-                FilterStrategy::Bigrams
-            },
-            interlace: Some(false),
+            filter: indexset! {RowFilter::None, RowFilter::Sub, RowFilter::Entropy, RowFilter::Bigrams},
+            interlace: Some(Interlacing::None),
             optimize_alpha: false,
             bit_depth_reduction: true,
             color_type_reduction: true,
@@ -294,10 +257,9 @@ impl Default for Options {
             idat_recoding: true,
             scale_16: false,
             strip: StripChunks::None,
-            deflater: Deflater::Libdeflater { compression: 11 },
+            deflate: Deflaters::Libdeflater { compression: 11 },
             fast_evaluation: true,
             timeout: None,
-            max_decompressed_size: None,
         }
     }
 }

src/png/mod.rs

@@ -1,24 +1,36 @@
-use std::{fs, path::Path, sync::Arc};
+use std::{
+    fs::File,
+    io::{BufReader, Read, Write},
+    path::Path,
+    sync::Arc,
+};
 
+use bitvec::bitarr;
 use libdeflater::{CompressionLvl, Compressor};
 use log::warn;
+use rgb::ComponentSlice;
 use rustc_hash::FxHashMap;
 
 use crate::{
-    Options, PngResult,
     apng::*,
     colors::{BitDepth, ColorType},
     deflate,
     error::PngError,
     filters::*,
     headers::*,
-    interlace::{deinterlace_image, interlace_image},
+    interlace::{deinterlace_image, interlace_image, Interlacing},
+    Options,
 };
 
 pub(crate) mod scan_lines;
 
 use self::scan_lines::ScanLines;
 
+/// Compression level to use for the Brute filter strategy
+const BRUTE_LEVEL: i32 = 1; // 1 is fastest, 2-4 are not useful, 5 is slower but more effective
+/// Number of lines to compress with the Brute filter strategy
+const BRUTE_LINES: usize = 4; // Values over 8 are generally not useful
+
 #[derive(Debug, Clone)]
 pub struct PngImage {
     /// The headers stored in the IHDR chunk
@@ -43,18 +55,39 @@ pub struct PngData {
 impl PngData {
     /// Create a new `PngData` struct by opening a file
     #[inline]
-    pub fn new(filepath: &Path, opts: &Options) -> PngResult<Self> {
+    pub fn new(filepath: &Path, opts: &Options) -> Result<Self, PngError> {
         let byte_data = Self::read_file(filepath)?;
 
         Self::from_slice(&byte_data, opts)
     }
 
-    pub fn read_file(filepath: &Path) -> PngResult<Vec<u8>> {
-        fs::read(filepath).map_err(|e| PngError::ReadFailed(filepath.display().to_string(), e))
+    pub fn read_file(filepath: &Path) -> Result<Vec<u8>, PngError> {
+        let file = match File::open(filepath) {
+            Ok(f) => f,
+            Err(_) => return Err(PngError::new("Failed to open file for reading")),
+        };
+        let file_len = file.metadata().map(|m| m.len() as usize).unwrap_or(0);
+        let mut reader = BufReader::new(file);
+        // Check file for PNG header
+        let mut header = [0; 8];
+        if reader.read_exact(&mut header).is_err() {
+            return Err(PngError::new("Not a PNG file: too small"));
+        }
+        if !file_header_is_valid(&header) {
+            return Err(PngError::new("Invalid PNG header detected"));
+        }
+        // Read raw png data into memory
+        let mut byte_data: Vec<u8> = Vec::with_capacity(file_len);
+        byte_data.extend_from_slice(&header);
+        match reader.read_to_end(&mut byte_data) {
+            Ok(_) => (),
+            Err(_) => return Err(PngError::new("Failed to read from file")),
+        }
+        Ok(byte_data)
     }
 
     /// Create a new `PngData` struct by reading a slice
-    pub fn from_slice(byte_data: &[u8], opts: &Options) -> PngResult<Self> {
+    pub fn from_slice(byte_data: &[u8], opts: &Options) -> Result<Self, PngError> {
         let mut byte_offset: usize = 0;
         // Test that png header is valid
         let header = byte_data.get(0..8).ok_or(PngError::TruncatedData)?;
@@ -121,7 +154,7 @@ impl PngData {
                     });
                 }
                 b"acTL" => {
-                    warn!("Stripping animation data from APNG - image will become standard PNG");
+                    warn!("Stripping animation data from APNG - image will become standard PNG")
                 }
                 _ => (),
             }
@@ -131,19 +164,15 @@ impl PngData {
         if idat_data.is_empty() {
             return Err(PngError::ChunkMissing("IDAT"));
         }
-        let Some(ihdr_chunk) = key_chunks.remove(b"IHDR") else {
-            return Err(PngError::ChunkMissing("IHDR"));
+        let ihdr_chunk = match key_chunks.remove(b"IHDR") {
+            Some(ihdr) => ihdr,
+            None => return Err(PngError::ChunkMissing("IHDR")),
         };
         let ihdr = parse_ihdr_chunk(
             &ihdr_chunk,
             key_chunks.remove(b"PLTE"),
             key_chunks.remove(b"tRNS"),
         )?;
-        if let Some(max) = opts.max_decompressed_size {
-            if ihdr.raw_data_size() > max {
-                return Err(PngError::InflatedDataTooLong(max));
-            }
-        }
 
         let raw = PngImage::new(ihdr, &idat_data)?;
 
@@ -163,15 +192,17 @@ impl PngData {
         let mut output = vec![0x89, 0x50, 0x4E, 0x47, 0x0D, 0x0A, 0x1A, 0x0A];
         // IHDR
         let mut ihdr_data = Vec::with_capacity(13);
-        ihdr_data.extend_from_slice(&self.raw.ihdr.width.to_be_bytes());
-        ihdr_data.extend_from_slice(&self.raw.ihdr.height.to_be_bytes());
-        ihdr_data.extend_from_slice(&[self.raw.ihdr.bit_depth as u8]);
-        ihdr_data.extend_from_slice(&[
-            self.raw.ihdr.color_type.png_header_code(),
-            0, // Compression -- deflate
-            0, // Filter method -- 5-way adaptive filtering
-            self.raw.ihdr.interlaced as u8,
-        ]);
+        ihdr_data.write_all(&self.raw.ihdr.width.to_be_bytes()).ok();
+        ihdr_data
+            .write_all(&self.raw.ihdr.height.to_be_bytes())
+            .ok();
+        ihdr_data.write_all(&[self.raw.ihdr.bit_depth as u8]).ok();
+        ihdr_data
+            .write_all(&[self.raw.ihdr.color_type.png_header_code()])
+            .ok();
+        ihdr_data.write_all(&[0]).ok(); // Compression -- deflate
+        ihdr_data.write_all(&[0]).ok(); // Filter method -- 5-way adaptive filtering
+        ihdr_data.write_all(&[self.raw.ihdr.interlaced as u8]).ok();
         write_png_block(b"IHDR", &ihdr_data, &mut output);
         // Ancillary chunks - split into those that come before IDAT and those that come after
         let mut aux_split = self.aux_chunks.split(|c| &c.name == b"IDAT");
@@ -190,7 +221,7 @@ impl PngData {
             ColorType::Indexed { palette } => {
                 let mut palette_data = Vec::with_capacity(palette.len() * 3);
                 for px in palette {
-                    palette_data.extend_from_slice(px.rgb().as_ref());
+                    palette_data.extend_from_slice(px.rgb().as_slice());
                 }
                 write_png_block(b"PLTE", &palette_data, &mut output);
                 if let Some(last_trns) = palette.iter().rposition(|px| px.a != 255) {
@@ -246,7 +277,7 @@ impl PngData {
 }
 
 impl PngImage {
-    pub fn new(ihdr: IhdrData, compressed_data: &[u8]) -> PngResult<Self> {
+    pub fn new(ihdr: IhdrData, compressed_data: &[u8]) -> Result<Self, PngError> {
         let raw_data = deflate::inflate(compressed_data, ihdr.raw_data_size())?;
 
         // Reject files with incorrect width/height or truncated data
@@ -262,17 +293,18 @@ impl PngImage {
         Ok(image)
     }
 
-    /// Enable or disable interlacing
-    /// Returns the new image if the interlacing was changed, None otherwise
+    /// Convert the image to the specified interlacing type
+    /// Returns true if the interlacing was changed, false otherwise
+    /// The `interlace` parameter specifies the *new* interlacing mode
     /// Assumes that the data has already been de-filtered
     #[inline]
     #[must_use]
-    pub fn change_interlacing(&self, interlace: bool) -> Option<Self> {
+    pub fn change_interlacing(&self, interlace: Interlacing) -> Option<Self> {
         if interlace == self.ihdr.interlaced {
             return None;
         }
 
-        Some(if interlace {
+        Some(if interlace == Interlacing::Adam7 {
             // Convert progressive to interlaced data
             interlace_image(self)
         } else {
@@ -305,10 +337,11 @@ impl PngImage {
         match &self.ihdr.color_type {
             ColorType::Indexed { palette } => {
                 let plte = 12 + palette.len() * 3;
-                palette
-                    .iter()
-                    .rposition(|p| p.a != 255)
-                    .map_or(plte, |trns| plte + 12 + trns + 1)
+                if let Some(trns) = palette.iter().rposition(|p| p.a != 255) {
+                    plte + 12 + trns + 1
+                } else {
+                    plte
+                }
             }
             ColorType::Grayscale { transparent_shade } if transparent_shade.is_some() => 12 + 2,
             ColorType::RGB { transparent_color } if transparent_color.is_some() => 12 + 6,
@@ -330,7 +363,7 @@ impl PngImage {
     }
 
     /// Reverse all filters applied on the image, returning an unfiltered IDAT bytestream
-    fn unfilter_image(&self) -> PngResult<Vec<u8>> {
+    fn unfilter_image(&self) -> Result<Vec<u8>, PngError> {
         let mut unfiltered = Vec::with_capacity(self.data.len());
         let bpp = self.bytes_per_channel() * self.channels_per_pixel();
         let mut last_line: Vec<u8> = Vec::new();
@@ -342,8 +375,8 @@ impl PngImage {
                 last_pass = line.pass;
             }
             last_line.resize(line.data.len(), 0);
-            let filter = RowFilter::try_from(line.filter).map_err(|()| PngError::InvalidData)?;
-            filter.unfilter_line(bpp, line.data, &last_line, &mut unfiltered_buf);
+            let filter = RowFilter::try_from(line.filter).map_err(|_| PngError::InvalidData)?;
+            filter.unfilter_line(bpp, line.data, &last_line, &mut unfiltered_buf)?;
             unfiltered.extend_from_slice(&unfiltered_buf);
             std::mem::swap(&mut last_line, &mut unfiltered_buf);
             unfiltered_buf.clear();
@@ -353,11 +386,7 @@ impl PngImage {
 
     /// Apply the specified filter type to all rows in the image
     #[must_use]
-    pub fn filter_image(
-        &self,
-        strategy: FilterStrategy,
-        optimize_alpha: bool,
-    ) -> (Vec<u8>, FilterStrategy) {
+    pub fn filter_image(&self, filter: RowFilter, optimize_alpha: bool) -> Vec<u8> {
         let mut filtered = Vec::with_capacity(self.data.len());
         let bpp = self.bytes_per_channel() * self.channels_per_pixel();
         // If alpha optimization is enabled, determine how many bytes of alpha there are per pixel
@@ -370,45 +399,31 @@ impl PngImage {
         let mut prev_line = Vec::new();
         let mut prev_pass: Option<u8> = None;
         let mut f_buf = Vec::new();
-        // For heuristic strategies, keep track of the actual filter used for each line
-        let mut filters_used = Vec::new();
-        // Pre-allocate buffers for the Bigrams strategy to avoid per-line allocations
-        let (mut bigram_seen, mut bigram_touched) = if matches!(strategy, FilterStrategy::Bigrams) {
-            (vec![false; 0x10000], Vec::<u16>::new())
-        } else {
-            (Vec::new(), Vec::new())
-        };
-        for (i, line) in self.scan_lines(false).enumerate() {
+        for line in self.scan_lines(false) {
             if prev_pass != line.pass || line.data.len() != prev_line.len() {
                 prev_line = vec![0; line.data.len()];
             }
             // Alpha optimisation may alter the line data, so we need a mutable copy of it
             let mut line_data = line.data.to_vec();
 
-            if let FilterStrategy::Basic(mut filter) = strategy {
+            if filter <= RowFilter::Paeth {
                 // Standard filters
-                if prev_pass != line.pass && filter > RowFilter::Sub {
-                    filter = RowFilter::None;
-                }
-                filter.filter_line(bpp, &mut line_data, &prev_line, &mut f_buf, alpha_bytes);
-                filtered.extend_from_slice(&f_buf);
-                prev_line = line_data;
-            } else if let FilterStrategy::Predefined(lines) = &strategy {
-                // Predefined filter for each line
-                let filter = lines.get(i).unwrap_or(&RowFilter::None);
+                let filter = if prev_pass == line.pass || filter <= RowFilter::Sub {
+                    filter
+                } else {
+                    RowFilter::None
+                };
                 filter.filter_line(bpp, &mut line_data, &prev_line, &mut f_buf, alpha_bytes);
                 filtered.extend_from_slice(&f_buf);
                 prev_line = line_data;
             } else {
                 // Heuristic filter selection strategies
 
-                let mut best_filter = RowFilter::None;
                 if line_data.iter().all(|&x| x == 0) {
                     // Assume None if the line is all zeros
-                    filtered.push(best_filter as u8);
+                    filtered.push(RowFilter::None as u8);
                     filtered.extend_from_slice(&line_data);
                     prev_line = line_data;
-                    filters_used.push(best_filter);
                     continue;
                 }
 
@@ -416,12 +431,12 @@ impl PngImage {
                 let mut best_line_raw = Vec::new();
                 // Avoid vertical filtering on first line of each interlacing pass
                 let try_filters = if prev_pass == line.pass {
-                    RowFilter::ALL.iter()
+                    RowFilter::STANDARD.iter()
                 } else {
                     RowFilter::SINGLE_LINE.iter()
                 };
-                match strategy {
-                    FilterStrategy::MinSum => {
+                match filter {
+                    RowFilter::MinSum => {
                         // MSAD algorithm mentioned in libpng reference docs
                         // http://www.libpng.org/pub/png/book/chapter09.html
                         let mut best_size = usize::MAX;
@@ -435,11 +450,10 @@ impl PngImage {
                                 best_size = size;
                                 std::mem::swap(&mut best_line, &mut f_buf);
                                 best_line_raw.clone_from(&line_data);
-                                best_filter = *f;
                             }
                         }
                     }
-                    FilterStrategy::Entropy => {
+                    RowFilter::Entropy => {
                         // Shannon entropy algorithm, from LodePNG
                         // https://github.com/lvandeve/lodepng
                         let mut best_size = i32::MIN;
@@ -459,42 +473,29 @@ impl PngImage {
                                 best_size = size;
                                 std::mem::swap(&mut best_line, &mut f_buf);
                                 best_line_raw.clone_from(&line_data);
-                                best_filter = *f;
                             }
                         }
                     }
-                    FilterStrategy::Bigrams => {
+                    RowFilter::Bigrams => {
                         // Count distinct bigrams, from pngwolf
                         // https://bjoern.hoehrmann.de/pngwolf/
                         let mut best_size = usize::MAX;
                         for f in try_filters {
                             f.filter_line(bpp, &mut line_data, &prev_line, &mut f_buf, alpha_bytes);
-                            let mut count = 0;
+                            let mut set = bitarr![0; 0x10000];
                             for pair in f_buf.windows(2) {
                                 let bigram = ((pair[0] as usize) << 8) | pair[1] as usize;
-                                if !bigram_seen[bigram] {
-                                    count += 1;
-                                    if count >= best_size {
-                                        break;
-                                    }
-                                    bigram_seen[bigram] = true;
-                                    bigram_touched.push(bigram as u16);
-                                }
+                                set.set(bigram, true);
                             }
-                            if count < best_size {
-                                best_size = count;
+                            let size = set.count_ones();
+                            if size < best_size {
+                                best_size = size;
                                 std::mem::swap(&mut best_line, &mut f_buf);
                                 best_line_raw.clone_from(&line_data);
-                                best_filter = *f;
                             }
-                            // Clear only the entries that were touched
-                            for &idx in &bigram_touched {
-                                bigram_seen[idx as usize] = false;
-                            }
-                            bigram_touched.clear();
                         }
                     }
-                    FilterStrategy::BigEnt => {
+                    RowFilter::BigEnt => {
                         // Bigram entropy, combined from Entropy and Bigrams filters
                         let mut best_size = i32::MIN;
                         // FxHasher is the fastest rust hasher currently available for this purpose
@@ -511,33 +512,31 @@ impl PngImage {
                                 best_size = size;
                                 std::mem::swap(&mut best_line, &mut f_buf);
                                 best_line_raw.clone_from(&line_data);
-                                best_filter = *f;
                             }
                         }
                     }
-                    FilterStrategy::Brute { num_lines, level } => {
+                    RowFilter::Brute => {
                         // Brute force by compressing each filter attempt
                         // Similar to that of LodePNG but includes some previous lines for context
                         let mut best_size = usize::MAX;
                         let line_start = filtered.len();
                         filtered.resize(filtered.len() + line.data.len() + 1, 0);
                         let mut compressor =
-                            Compressor::new(CompressionLvl::new(level.into()).unwrap());
-                        let limit = filtered.len().min((line.data.len() + 1) * num_lines);
-                        let capacity = compressor.deflate_compress_bound(limit);
+                            Compressor::new(CompressionLvl::new(BRUTE_LEVEL).unwrap());
+                        let limit = filtered.len().min((line.data.len() + 1) * BRUTE_LINES);
+                        let capacity = compressor.zlib_compress_bound(limit);
                         let mut dest = vec![0; capacity];
 
                         for f in try_filters {
                             f.filter_line(bpp, &mut line_data, &prev_line, &mut f_buf, alpha_bytes);
                             filtered[line_start..].copy_from_slice(&f_buf);
                             let size = compressor
-                                .deflate_compress(&filtered[filtered.len() - limit..], &mut dest)
+                                .zlib_compress(&filtered[filtered.len() - limit..], &mut dest)
                                 .unwrap_or(usize::MAX);
                             if size < best_size {
                                 best_size = size;
                                 std::mem::swap(&mut best_line, &mut f_buf);
                                 best_line_raw.clone_from(&line_data);
-                                best_filter = *f;
                             }
                         }
                         filtered.resize(line_start, 0);
@@ -546,17 +545,11 @@ impl PngImage {
                 }
                 filtered.extend_from_slice(&best_line);
                 prev_line = best_line_raw;
-                filters_used.push(best_filter);
             }
 
             prev_pass = line.pass;
         }
-
-        if filters_used.is_empty() {
-            (filtered, strategy)
-        } else {
-            (filtered, FilterStrategy::Predefined(filters_used))
-        }
+        filtered
     }
 }
 

src/png/scan_lines.rs

@@ -1,4 +1,4 @@
-use crate::png::PngImage;
+use crate::{interlace::Interlacing, png::PngImage};
 
 /// An iterator over the scan lines of a PNG image
 #[derive(Debug, Clone)]
@@ -69,7 +69,7 @@ impl ScanLineRanges {
             width: png.ihdr.width,
             height: png.ihdr.height,
             left: png.data.len(),
-            pass: if png.ihdr.interlaced {
+            pass: if png.ihdr.interlaced == Interlacing::Adam7 {
                 Some((1, 0))
             } else {
                 None
@@ -138,7 +138,7 @@ impl Iterator for ScanLineRanges {
                     pixels_per_line += 1;
                 }
                 _ => (),
-            }
+            };
             let current_pass = Some(pass.0);
             if pass.1 + y_steps >= self.height {
                 pass.0 += 1;

src/reduction/alpha.rs

@@ -81,7 +81,7 @@ pub fn reduced_alpha_channel(png: &PngImage, optimize_alpha: bool) -> Option<Png
                 raw_data.resize(raw_data.len() + colored_bytes, trns);
             }
             _ => raw_data.extend_from_slice(&pixel[0..colored_bytes]),
-        }
+        };
     }
 
     // Construct the color type with appropriate transparency data

src/reduction/bit_depth.rs

@@ -70,17 +70,17 @@ pub fn reduced_bit_depth_8_or_less(png: &PngImage) -> Option<PngImage> {
         return None;
     }
 
-    let minimum_bits = if let ColorType::Indexed { palette } = &png.ihdr.color_type {
+    let mut minimum_bits = 1;
+
+    if let ColorType::Indexed { palette } = &png.ihdr.color_type {
         // We can easily determine minimum depth by the palette size
-        match palette.len() {
+        minimum_bits = match palette.len() {
             0..=2 => 1,
             3..=4 => 2,
             5..=16 => 4,
             _ => return None,
-        }
+        };
     } else {
-        let mut minimum_bits = 1;
-
         // Finding minimum depth for grayscale is much more complicated
         let mut mask = 1;
         let mut divisions = 1..8;
@@ -110,9 +110,7 @@ pub fn reduced_bit_depth_8_or_less(png: &PngImage) -> Option<PngImage> {
                 break;
             }
         }
-
-        minimum_bits
-    };
+    }
 
     let mut reduced = Vec::with_capacity(png.data.len());
     let mask = (1 << minimum_bits) - 1;

src/reduction/color.rs

@@ -1,7 +1,7 @@
 use std::hash::{BuildHasherDefault, Hash};
 
 use indexmap::IndexSet;
-use rgb::{ComponentMap, FromSlice, RGB, RGBA, alt::Gray};
+use rgb::{alt::Gray, ComponentMap, ComponentSlice, FromSlice, RGB, RGBA};
 use rustc_hash::FxHasher;
 
 use crate::{
@@ -54,10 +54,10 @@ pub fn reduced_to_indexed(png: &PngImage, allow_grayscale: bool) -> Option<PngIm
             let transparency_pixel = transparent_shade.map(|t| Gray::from(t as u8));
             pmap.into_iter()
                 .map(|px| {
-                    RGB::from(px).with_alpha(if Some(px) == transparency_pixel {
-                        0
-                    } else {
+                    RGB::from(px).with_alpha(if Some(px) != transparency_pixel {
                         255
+                    } else {
+                        0
                     })
                 })
                 .collect()
@@ -68,10 +68,10 @@ pub fn reduced_to_indexed(png: &PngImage, allow_grayscale: bool) -> Option<PngIm
             let transparency_pixel = transparent_color.map(|t| t.map(|c| c as u8));
             pmap.into_iter()
                 .map(|px| {
-                    px.with_alpha(if Some(px) == transparency_pixel {
-                        0
-                    } else {
+                    px.with_alpha(if Some(px) != transparency_pixel {
                         255
+                    } else {
+                        0
                     })
                 })
                 .collect()
@@ -193,7 +193,7 @@ pub fn indexed_to_channels(
     let mut data = Vec::with_capacity(out_size);
     for b in &png.data {
         let color = palette.get(*b as usize).unwrap_or(&black);
-        data.extend_from_slice(&color.as_ref()[ch_start..=ch_end]);
+        data.extend_from_slice(&color.as_slice()[ch_start..=ch_end]);
     }
 
     Some(PngImage {

src/reduction/mod.rs

@@ -1,6 +1,6 @@
 use std::sync::Arc;
 
-use crate::{ColorType, Deadline, Deflater, Options, evaluate::Evaluator, png::PngImage};
+use crate::{evaluate::Evaluator, png::PngImage, ColorType, Deadline, Deflaters, Options};
 
 pub mod alpha;
 use crate::alpha::*;
@@ -21,8 +21,8 @@ pub(crate) fn perform_reductions(
 
     // At low compression levels, skip some transformations which are less likely to be effective
     // This currently affects optimization presets 0-2
-    let cheap = match opts.deflater {
-        Deflater::Libdeflater { compression } => compression < 12 && opts.fast_evaluation,
+    let cheap = match opts.deflate {
+        Deflaters::Libdeflater { compression } => compression < 12 && opts.fast_evaluation,
         _ => false,
     };
 
@@ -118,7 +118,7 @@ pub(crate) fn perform_reductions(
     // Attempt to reduce to indexed
     // Keep the existing `png` var in case it is grayscale - we can test both for depth reduction later
     let mut indexed = None;
-    if opts.color_type_reduction && opts.palette_reduction && !deadline.passed() {
+    if opts.color_type_reduction && !deadline.passed() {
         if let Some(reduced) = reduced_to_indexed(&png, opts.grayscale_reduction) {
             // Make sure the palette gets sorted (but don't bother evaluating both results)
             let new = Arc::new(sorted_palette(&reduced).unwrap_or(reduced));
@@ -183,7 +183,7 @@ pub(crate) fn perform_reductions(
         if (!cheap || reduced.is_none()) && !deadline.passed() {
             if let Some(indexed) = indexed.and_then(|png| reduced_bit_depth_8_or_less(&png)) {
                 // Only evaluate this if it's different from the first result (which must be grayscale if it exists)
-                if reduced.as_ref().is_none_or(|r| r.data != indexed.data) {
+                if reduced.as_ref().map_or(true, |r| r.data != indexed.data) {
                     eval.try_image(Arc::new(indexed));
                     evaluation_added = true;
                 }

src/reduction/palette.rs

@@ -4,7 +4,8 @@ use rgb::RGBA8;
 use crate::{
     colors::{BitDepth, ColorType},
     headers::IhdrData,
-    png::{PngImage, scan_lines::ScanLine},
+    png::{scan_lines::ScanLine, PngImage},
+    Interlacing,
 };
 
 /// Attempt to reduce the number of colors in the palette, returning the reduced image if successful
@@ -133,7 +134,7 @@ pub fn sorted_palette(png: &PngImage) -> Option<PngImage> {
 #[must_use]
 pub fn sorted_palette_mzeng(png: &PngImage) -> Option<PngImage> {
     // Interlacing not currently supported
-    if png.ihdr.bit_depth != BitDepth::Eight || png.ihdr.interlaced {
+    if png.ihdr.bit_depth != BitDepth::Eight || png.ihdr.interlaced != Interlacing::None {
         return None;
     }
     let palette = match &png.ihdr.color_type {
@@ -155,7 +156,7 @@ pub fn sorted_palette_mzeng(png: &PngImage) -> Option<PngImage> {
 #[must_use]
 pub fn sorted_palette_battiato(png: &PngImage) -> Option<PngImage> {
     // Interlacing not currently supported
-    if png.ihdr.bit_depth != BitDepth::Eight || png.ihdr.interlaced {
+    if png.ihdr.bit_depth != BitDepth::Eight || png.ihdr.interlaced != Interlacing::None {
         return None;
     }
     let palette = match &png.ihdr.color_type {
@@ -206,7 +207,7 @@ fn apply_palette_reorder(png: &PngImage, remapping: &[usize]) -> Option<PngImage
 
 // Find the most popular color on the image edges (the pixels neighboring the filter bytes)
 fn most_popular_edge_color(num_colors: usize, png: &PngImage) -> Option<usize> {
-    let mut counts = [0_u32; 256];
+    let mut counts = [0u32; 256];
     for line in png.scan_lines(false) {
         if let &[first, .., last] = line.data {
             counts[first as usize] += 1;
@@ -229,7 +230,7 @@ fn most_popular_edge_color(num_colors: usize, png: &PngImage) -> Option<usize> {
 
 // Find the most popular color in the image, along with its count
 fn most_popular_color(num_colors: usize, png: &PngImage) -> (usize, u32) {
-    let mut counts = [0_u32; 256];
+    let mut counts = [0u32; 256];
     for &val in &png.data {
         counts[val as usize] += 1;
     }
@@ -261,7 +262,7 @@ fn apply_most_popular_color(png: &PngImage, remapping: &mut [usize]) {
 
 // Calculate co-occurences matrix
 fn co_occurrence_matrix(num_colors: usize, png: &PngImage) -> Vec<Vec<u32>> {
-    let mut matrix = vec![vec![0_u32; num_colors]; num_colors];
+    let mut matrix = vec![vec![0u32; num_colors]; num_colors];
     let mut prev: Option<ScanLine> = None;
     let mut prev_val = None;
     for line in png.scan_lines(false) {

src/sanity_checks.rs

@@ -44,7 +44,7 @@ fn load_png_image_from_memory(png_data: &[u8]) -> Result<Vec<RgbaImage>, image::
         decoder
             .apng()?
             .into_frames()
-            .map(|f| f.map(image::Frame::into_buffer))
+            .map(|f| f.map(|f| f.into_buffer()))
             .collect()
     } else {
         DynamicImage::from_decoder(decoder).map(|i| vec![i.into_rgba8()])

tests/alpha.rs

@@ -1,346 +0,0 @@
-use std::{
-    fs::remove_file,
-    path::{Path, PathBuf},
-};
-
-use oxipng::{internal_tests::*, *};
-
-const GRAYSCALE_ALPHA: u8 = 4;
-const RGBA: u8 = 6;
-
-fn get_opts(input: &Path) -> (OutFile, oxipng::Options) {
-    let options = oxipng::Options {
-        force: true,
-        optimize_alpha: true,
-        ..Default::default()
-    };
-    (OutFile::from_path(input.with_extension("out.png")), options)
-}
-
-fn test_it_converts(
-    input: &str,
-    filter: FilterStrategy,
-    color_type_in: u8,
-    bit_depth_in: BitDepth,
-    color_type_out: u8,
-    bit_depth_out: BitDepth,
-) {
-    let input = PathBuf::from(input);
-
-    let (output, mut opts) = get_opts(&input);
-    let png = PngData::new(&input, &opts).unwrap();
-    opts.filters = indexset! {filter};
-    assert_eq!(png.raw.ihdr.color_type.png_header_code(), color_type_in);
-    assert_eq!(png.raw.ihdr.bit_depth, bit_depth_in);
-
-    match oxipng::optimize(&InFile::Path(input), &output, &opts) {
-        Ok(_) => (),
-        Err(x) => panic!("{}", x),
-    }
-    let output = output.path().unwrap();
-    assert!(output.exists());
-
-    let png = match PngData::new(output, &opts) {
-        Ok(x) => x,
-        Err(x) => {
-            remove_file(output).ok();
-            panic!("{}", x)
-        }
-    };
-
-    assert_eq!(png.raw.ihdr.color_type.png_header_code(), color_type_out);
-    assert_eq!(png.raw.ihdr.bit_depth, bit_depth_out);
-    if let ColorType::Indexed { palette } = &png.raw.ihdr.color_type {
-        assert!(palette.len() <= 1 << (png.raw.ihdr.bit_depth as u8));
-    }
-
-    remove_file(output).ok();
-}
-
-#[test]
-fn alpha_filter_0_for_rgba_16() {
-    test_it_converts(
-        "tests/files/filter_0_for_rgba_16.png",
-        FilterStrategy::NONE,
-        RGBA,
-        BitDepth::Sixteen,
-        RGBA,
-        BitDepth::Sixteen,
-    );
-}
-
-#[test]
-fn alpha_filter_1_for_rgba_16() {
-    test_it_converts(
-        "tests/files/filter_1_for_rgba_16.png",
-        FilterStrategy::SUB,
-        RGBA,
-        BitDepth::Sixteen,
-        RGBA,
-        BitDepth::Sixteen,
-    );
-}
-
-#[test]
-fn alpha_filter_2_for_rgba_16() {
-    test_it_converts(
-        "tests/files/filter_2_for_rgba_16.png",
-        FilterStrategy::UP,
-        RGBA,
-        BitDepth::Sixteen,
-        RGBA,
-        BitDepth::Sixteen,
-    );
-}
-
-#[test]
-fn alpha_filter_3_for_rgba_16() {
-    test_it_converts(
-        "tests/files/filter_3_for_rgba_16.png",
-        FilterStrategy::AVERAGE,
-        RGBA,
-        BitDepth::Sixteen,
-        RGBA,
-        BitDepth::Sixteen,
-    );
-}
-
-#[test]
-fn alpha_filter_4_for_rgba_16() {
-    test_it_converts(
-        "tests/files/filter_4_for_rgba_16.png",
-        FilterStrategy::PAETH,
-        RGBA,
-        BitDepth::Sixteen,
-        RGBA,
-        BitDepth::Sixteen,
-    );
-}
-
-#[test]
-fn alpha_filter_5_for_rgba_16() {
-    test_it_converts(
-        "tests/files/filter_5_for_rgba_16.png",
-        FilterStrategy::MinSum,
-        RGBA,
-        BitDepth::Sixteen,
-        RGBA,
-        BitDepth::Sixteen,
-    );
-}
-
-#[test]
-fn alpha_filter_0_for_rgba_8() {
-    test_it_converts(
-        "tests/files/filter_0_for_rgba_8.png",
-        FilterStrategy::NONE,
-        RGBA,
-        BitDepth::Eight,
-        RGBA,
-        BitDepth::Eight,
-    );
-}
-
-#[test]
-fn alpha_filter_1_for_rgba_8() {
-    test_it_converts(
-        "tests/files/filter_1_for_rgba_8.png",
-        FilterStrategy::SUB,
-        RGBA,
-        BitDepth::Eight,
-        RGBA,
-        BitDepth::Eight,
-    );
-}
-
-#[test]
-fn alpha_filter_2_for_rgba_8() {
-    test_it_converts(
-        "tests/files/filter_2_for_rgba_8.png",
-        FilterStrategy::UP,
-        RGBA,
-        BitDepth::Eight,
-        RGBA,
-        BitDepth::Eight,
-    );
-}
-
-#[test]
-fn alpha_filter_3_for_rgba_8() {
-    test_it_converts(
-        "tests/files/filter_3_for_rgba_8.png",
-        FilterStrategy::AVERAGE,
-        RGBA,
-        BitDepth::Eight,
-        RGBA,
-        BitDepth::Eight,
-    );
-}
-
-#[test]
-fn alpha_filter_4_for_rgba_8() {
-    test_it_converts(
-        "tests/files/filter_4_for_rgba_8.png",
-        FilterStrategy::PAETH,
-        RGBA,
-        BitDepth::Eight,
-        RGBA,
-        BitDepth::Eight,
-    );
-}
-
-#[test]
-fn alpha_filter_5_for_rgba_8() {
-    test_it_converts(
-        "tests/files/filter_5_for_rgba_8.png",
-        FilterStrategy::MinSum,
-        RGBA,
-        BitDepth::Eight,
-        RGBA,
-        BitDepth::Eight,
-    );
-}
-
-#[test]
-fn alpha_filter_0_for_grayscale_alpha_16() {
-    test_it_converts(
-        "tests/files/filter_0_for_grayscale_alpha_16.png",
-        FilterStrategy::NONE,
-        GRAYSCALE_ALPHA,
-        BitDepth::Sixteen,
-        GRAYSCALE_ALPHA,
-        BitDepth::Sixteen,
-    );
-}
-
-#[test]
-fn alpha_filter_1_for_grayscale_alpha_16() {
-    test_it_converts(
-        "tests/files/filter_1_for_grayscale_alpha_16.png",
-        FilterStrategy::SUB,
-        GRAYSCALE_ALPHA,
-        BitDepth::Sixteen,
-        GRAYSCALE_ALPHA,
-        BitDepth::Sixteen,
-    );
-}
-
-#[test]
-fn alpha_filter_2_for_grayscale_alpha_16() {
-    test_it_converts(
-        "tests/files/filter_2_for_grayscale_alpha_16.png",
-        FilterStrategy::UP,
-        GRAYSCALE_ALPHA,
-        BitDepth::Sixteen,
-        GRAYSCALE_ALPHA,
-        BitDepth::Sixteen,
-    );
-}
-
-#[test]
-fn alpha_filter_3_for_grayscale_alpha_16() {
-    test_it_converts(
-        "tests/files/filter_3_for_grayscale_alpha_16.png",
-        FilterStrategy::AVERAGE,
-        GRAYSCALE_ALPHA,
-        BitDepth::Sixteen,
-        GRAYSCALE_ALPHA,
-        BitDepth::Sixteen,
-    );
-}
-
-#[test]
-fn alpha_filter_4_for_grayscale_alpha_16() {
-    test_it_converts(
-        "tests/files/filter_4_for_grayscale_alpha_16.png",
-        FilterStrategy::PAETH,
-        GRAYSCALE_ALPHA,
-        BitDepth::Sixteen,
-        GRAYSCALE_ALPHA,
-        BitDepth::Sixteen,
-    );
-}
-
-#[test]
-fn alpha_filter_5_for_grayscale_alpha_16() {
-    test_it_converts(
-        "tests/files/filter_5_for_grayscale_alpha_16.png",
-        FilterStrategy::MinSum,
-        GRAYSCALE_ALPHA,
-        BitDepth::Sixteen,
-        GRAYSCALE_ALPHA,
-        BitDepth::Sixteen,
-    );
-}
-
-#[test]
-fn alpha_filter_0_for_grayscale_alpha_8() {
-    test_it_converts(
-        "tests/files/filter_0_for_grayscale_alpha_8.png",
-        FilterStrategy::NONE,
-        GRAYSCALE_ALPHA,
-        BitDepth::Eight,
-        GRAYSCALE_ALPHA,
-        BitDepth::Eight,
-    );
-}
-
-#[test]
-fn alpha_filter_1_for_grayscale_alpha_8() {
-    test_it_converts(
-        "tests/files/filter_1_for_grayscale_alpha_8.png",
-        FilterStrategy::SUB,
-        GRAYSCALE_ALPHA,
-        BitDepth::Eight,
-        GRAYSCALE_ALPHA,
-        BitDepth::Eight,
-    );
-}
-
-#[test]
-fn alpha_filter_2_for_grayscale_alpha_8() {
-    test_it_converts(
-        "tests/files/filter_2_for_grayscale_alpha_8.png",
-        FilterStrategy::UP,
-        GRAYSCALE_ALPHA,
-        BitDepth::Eight,
-        GRAYSCALE_ALPHA,
-        BitDepth::Eight,
-    );
-}
-
-#[test]
-fn alpha_filter_3_for_grayscale_alpha_8() {
-    test_it_converts(
-        "tests/files/filter_3_for_grayscale_alpha_8.png",
-        FilterStrategy::AVERAGE,
-        GRAYSCALE_ALPHA,
-        BitDepth::Eight,
-        GRAYSCALE_ALPHA,
-        BitDepth::Eight,
-    );
-}
-
-#[test]
-fn alpha_filter_4_for_grayscale_alpha_8() {
-    test_it_converts(
-        "tests/files/filter_4_for_grayscale_alpha_8.png",
-        FilterStrategy::PAETH,
-        GRAYSCALE_ALPHA,
-        BitDepth::Eight,
-        GRAYSCALE_ALPHA,
-        BitDepth::Eight,
-    );
-}
-
-#[test]
-fn alpha_filter_5_for_grayscale_alpha_8() {
-    test_it_converts(
-        "tests/files/filter_5_for_grayscale_alpha_8.png",
-        FilterStrategy::MinSum,
-        GRAYSCALE_ALPHA,
-        BitDepth::Eight,
-        GRAYSCALE_ALPHA,
-        BitDepth::Eight,
-    );
-}

tests/filters.rs

@@ -12,16 +12,20 @@ const GRAYSCALE_ALPHA: u8 = 4;
 const RGBA: u8 = 6;
 
 fn get_opts(input: &Path) -> (OutFile, oxipng::Options) {
-    let options = oxipng::Options {
+    let mut options = oxipng::Options {
         force: true,
         ..Default::default()
     };
+    let mut filter = IndexSet::new();
+    filter.insert(RowFilter::None);
+    options.filter = filter;
+
     (OutFile::from_path(input.with_extension("out.png")), options)
 }
 
 fn test_it_converts(
     input: &str,
-    filter: FilterStrategy,
+    filter: RowFilter,
     color_type_in: u8,
     bit_depth_in: BitDepth,
     color_type_out: u8,
@@ -31,14 +35,15 @@ fn test_it_converts(
 
     let (output, mut opts) = get_opts(&input);
     let png = PngData::new(&input, &opts).unwrap();
-    opts.filters = indexset! {filter};
+    opts.filter = IndexSet::new();
+    opts.filter.insert(filter);
     assert_eq!(png.raw.ihdr.color_type.png_header_code(), color_type_in);
     assert_eq!(png.raw.ihdr.bit_depth, bit_depth_in);
 
     match oxipng::optimize(&InFile::Path(input), &output, &opts) {
         Ok(_) => (),
         Err(x) => panic!("{}", x),
-    }
+    };
     let output = output.path().unwrap();
     assert!(output.exists());
 
@@ -63,7 +68,7 @@ fn test_it_converts(
 fn filter_0_for_rgba_16() {
     test_it_converts(
         "tests/files/filter_0_for_rgba_16.png",
-        FilterStrategy::NONE,
+        RowFilter::None,
         RGBA,
         BitDepth::Sixteen,
         RGBA,
@@ -75,7 +80,7 @@ fn filter_0_for_rgba_16() {
 fn filter_1_for_rgba_16() {
     test_it_converts(
         "tests/files/filter_1_for_rgba_16.png",
-        FilterStrategy::SUB,
+        RowFilter::Sub,
         RGBA,
         BitDepth::Sixteen,
         RGBA,
@@ -87,7 +92,7 @@ fn filter_1_for_rgba_16() {
 fn filter_2_for_rgba_16() {
     test_it_converts(
         "tests/files/filter_2_for_rgba_16.png",
-        FilterStrategy::UP,
+        RowFilter::Up,
         RGBA,
         BitDepth::Sixteen,
         RGBA,
@@ -99,7 +104,7 @@ fn filter_2_for_rgba_16() {
 fn filter_3_for_rgba_16() {
     test_it_converts(
         "tests/files/filter_3_for_rgba_16.png",
-        FilterStrategy::AVERAGE,
+        RowFilter::Average,
         RGBA,
         BitDepth::Sixteen,
         RGBA,
@@ -111,7 +116,7 @@ fn filter_3_for_rgba_16() {
 fn filter_4_for_rgba_16() {
     test_it_converts(
         "tests/files/filter_4_for_rgba_16.png",
-        FilterStrategy::PAETH,
+        RowFilter::Paeth,
         RGBA,
         BitDepth::Sixteen,
         RGBA,
@@ -123,7 +128,7 @@ fn filter_4_for_rgba_16() {
 fn filter_5_for_rgba_16() {
     test_it_converts(
         "tests/files/filter_5_for_rgba_16.png",
-        FilterStrategy::MinSum,
+        RowFilter::MinSum,
         RGBA,
         BitDepth::Sixteen,
         RGBA,
@@ -135,7 +140,7 @@ fn filter_5_for_rgba_16() {
 fn filter_0_for_rgba_8() {
     test_it_converts(
         "tests/files/filter_0_for_rgba_8.png",
-        FilterStrategy::NONE,
+        RowFilter::None,
         RGBA,
         BitDepth::Eight,
         RGBA,
@@ -147,7 +152,7 @@ fn filter_0_for_rgba_8() {
 fn filter_1_for_rgba_8() {
     test_it_converts(
         "tests/files/filter_1_for_rgba_8.png",
-        FilterStrategy::SUB,
+        RowFilter::Sub,
         RGBA,
         BitDepth::Eight,
         RGBA,
@@ -159,7 +164,7 @@ fn filter_1_for_rgba_8() {
 fn filter_2_for_rgba_8() {
     test_it_converts(
         "tests/files/filter_2_for_rgba_8.png",
-        FilterStrategy::UP,
+        RowFilter::Up,
         RGBA,
         BitDepth::Eight,
         RGBA,
@@ -171,7 +176,7 @@ fn filter_2_for_rgba_8() {
 fn filter_3_for_rgba_8() {
     test_it_converts(
         "tests/files/filter_3_for_rgba_8.png",
-        FilterStrategy::AVERAGE,
+        RowFilter::Average,
         RGBA,
         BitDepth::Eight,
         RGBA,
@@ -183,7 +188,7 @@ fn filter_3_for_rgba_8() {
 fn filter_4_for_rgba_8() {
     test_it_converts(
         "tests/files/filter_4_for_rgba_8.png",
-        FilterStrategy::PAETH,
+        RowFilter::Paeth,
         RGBA,
         BitDepth::Eight,
         RGBA,
@@ -195,7 +200,7 @@ fn filter_4_for_rgba_8() {
 fn filter_5_for_rgba_8() {
     test_it_converts(
         "tests/files/filter_5_for_rgba_8.png",
-        FilterStrategy::MinSum,
+        RowFilter::MinSum,
         RGBA,
         BitDepth::Eight,
         RGBA,
@@ -207,7 +212,7 @@ fn filter_5_for_rgba_8() {
 fn filter_0_for_rgb_16() {
     test_it_converts(
         "tests/files/filter_0_for_rgb_16.png",
-        FilterStrategy::NONE,
+        RowFilter::None,
         RGB,
         BitDepth::Sixteen,
         RGB,
@@ -219,7 +224,7 @@ fn filter_0_for_rgb_16() {
 fn filter_1_for_rgb_16() {
     test_it_converts(
         "tests/files/filter_1_for_rgb_16.png",
-        FilterStrategy::SUB,
+        RowFilter::Sub,
         RGB,
         BitDepth::Sixteen,
         RGB,
@@ -231,7 +236,7 @@ fn filter_1_for_rgb_16() {
 fn filter_2_for_rgb_16() {
     test_it_converts(
         "tests/files/filter_2_for_rgb_16.png",
-        FilterStrategy::UP,
+        RowFilter::Up,
         RGB,
         BitDepth::Sixteen,
         RGB,
@@ -243,7 +248,7 @@ fn filter_2_for_rgb_16() {
 fn filter_3_for_rgb_16() {
     test_it_converts(
         "tests/files/filter_3_for_rgb_16.png",
-        FilterStrategy::AVERAGE,
+        RowFilter::Average,
         RGB,
         BitDepth::Sixteen,
         RGB,
@@ -255,7 +260,7 @@ fn filter_3_for_rgb_16() {
 fn filter_4_for_rgb_16() {
     test_it_converts(
         "tests/files/filter_4_for_rgb_16.png",
-        FilterStrategy::PAETH,
+        RowFilter::Paeth,
         RGB,
         BitDepth::Sixteen,
         RGB,
@@ -267,7 +272,7 @@ fn filter_4_for_rgb_16() {
 fn filter_5_for_rgb_16() {
     test_it_converts(
         "tests/files/filter_5_for_rgb_16.png",
-        FilterStrategy::MinSum,
+        RowFilter::MinSum,
         RGB,
         BitDepth::Sixteen,
         RGB,
@@ -279,7 +284,7 @@ fn filter_5_for_rgb_16() {
 fn filter_0_for_rgb_8() {
     test_it_converts(
         "tests/files/filter_0_for_rgb_8.png",
-        FilterStrategy::NONE,
+        RowFilter::None,
         RGB,
         BitDepth::Eight,
         RGB,
@@ -291,7 +296,7 @@ fn filter_0_for_rgb_8() {
 fn filter_1_for_rgb_8() {
     test_it_converts(
         "tests/files/filter_1_for_rgb_8.png",
-        FilterStrategy::SUB,
+        RowFilter::Sub,
         RGB,
         BitDepth::Eight,
         RGB,
@@ -303,7 +308,7 @@ fn filter_1_for_rgb_8() {
 fn filter_2_for_rgb_8() {
     test_it_converts(
         "tests/files/filter_2_for_rgb_8.png",
-        FilterStrategy::UP,
+        RowFilter::Up,
         RGB,
         BitDepth::Eight,
         RGB,
@@ -315,7 +320,7 @@ fn filter_2_for_rgb_8() {
 fn filter_3_for_rgb_8() {
     test_it_converts(
         "tests/files/filter_3_for_rgb_8.png",
-        FilterStrategy::AVERAGE,
+        RowFilter::Average,
         RGB,
         BitDepth::Eight,
         RGB,
@@ -327,7 +332,7 @@ fn filter_3_for_rgb_8() {
 fn filter_4_for_rgb_8() {
     test_it_converts(
         "tests/files/filter_4_for_rgb_8.png",
-        FilterStrategy::PAETH,
+        RowFilter::Paeth,
         RGB,
         BitDepth::Eight,
         RGB,
@@ -339,7 +344,7 @@ fn filter_4_for_rgb_8() {
 fn filter_5_for_rgb_8() {
     test_it_converts(
         "tests/files/filter_5_for_rgb_8.png",
-        FilterStrategy::MinSum,
+        RowFilter::MinSum,
         RGB,
         BitDepth::Eight,
         RGB,
@@ -351,7 +356,7 @@ fn filter_5_for_rgb_8() {
 fn filter_0_for_grayscale_alpha_16() {
     test_it_converts(
         "tests/files/filter_0_for_grayscale_alpha_16.png",
-        FilterStrategy::NONE,
+        RowFilter::None,
         GRAYSCALE_ALPHA,
         BitDepth::Sixteen,
         GRAYSCALE_ALPHA,
@@ -363,7 +368,7 @@ fn filter_0_for_grayscale_alpha_16() {
 fn filter_1_for_grayscale_alpha_16() {
     test_it_converts(
         "tests/files/filter_1_for_grayscale_alpha_16.png",
-        FilterStrategy::SUB,
+        RowFilter::Sub,
         GRAYSCALE_ALPHA,
         BitDepth::Sixteen,
         GRAYSCALE_ALPHA,
@@ -375,7 +380,7 @@ fn filter_1_for_grayscale_alpha_16() {
 fn filter_2_for_grayscale_alpha_16() {
     test_it_converts(
         "tests/files/filter_2_for_grayscale_alpha_16.png",
-        FilterStrategy::UP,
+        RowFilter::Up,
         GRAYSCALE_ALPHA,
         BitDepth::Sixteen,
         GRAYSCALE_ALPHA,
@@ -387,7 +392,7 @@ fn filter_2_for_grayscale_alpha_16() {
 fn filter_3_for_grayscale_alpha_16() {
     test_it_converts(
         "tests/files/filter_3_for_grayscale_alpha_16.png",
-        FilterStrategy::AVERAGE,
+        RowFilter::Average,
         GRAYSCALE_ALPHA,
         BitDepth::Sixteen,
         GRAYSCALE_ALPHA,
@@ -399,7 +404,7 @@ fn filter_3_for_grayscale_alpha_16() {
 fn filter_4_for_grayscale_alpha_16() {
     test_it_converts(
         "tests/files/filter_4_for_grayscale_alpha_16.png",
-        FilterStrategy::PAETH,
+        RowFilter::Paeth,
         GRAYSCALE_ALPHA,
         BitDepth::Sixteen,
         GRAYSCALE_ALPHA,
@@ -411,7 +416,7 @@ fn filter_4_for_grayscale_alpha_16() {
 fn filter_5_for_grayscale_alpha_16() {
     test_it_converts(
         "tests/files/filter_5_for_grayscale_alpha_16.png",
-        FilterStrategy::MinSum,
+        RowFilter::MinSum,
         GRAYSCALE_ALPHA,
         BitDepth::Sixteen,
         GRAYSCALE_ALPHA,
@@ -423,7 +428,7 @@ fn filter_5_for_grayscale_alpha_16() {
 fn filter_0_for_grayscale_alpha_8() {
     test_it_converts(
         "tests/files/filter_0_for_grayscale_alpha_8.png",
-        FilterStrategy::NONE,
+        RowFilter::None,
         GRAYSCALE_ALPHA,
         BitDepth::Eight,
         GRAYSCALE_ALPHA,
@@ -435,7 +440,7 @@ fn filter_0_for_grayscale_alpha_8() {
 fn filter_1_for_grayscale_alpha_8() {
     test_it_converts(
         "tests/files/filter_1_for_grayscale_alpha_8.png",
-        FilterStrategy::SUB,
+        RowFilter::Sub,
         GRAYSCALE_ALPHA,
         BitDepth::Eight,
         GRAYSCALE_ALPHA,
@@ -447,7 +452,7 @@ fn filter_1_for_grayscale_alpha_8() {
 fn filter_2_for_grayscale_alpha_8() {
     test_it_converts(
         "tests/files/filter_2_for_grayscale_alpha_8.png",
-        FilterStrategy::UP,
+        RowFilter::Up,
         GRAYSCALE_ALPHA,
         BitDepth::Eight,
         GRAYSCALE_ALPHA,
@@ -459,7 +464,7 @@ fn filter_2_for_grayscale_alpha_8() {
 fn filter_3_for_grayscale_alpha_8() {
     test_it_converts(
         "tests/files/filter_3_for_grayscale_alpha_8.png",
-        FilterStrategy::AVERAGE,
+        RowFilter::Average,
         GRAYSCALE_ALPHA,
         BitDepth::Eight,
         GRAYSCALE_ALPHA,
@@ -471,7 +476,7 @@ fn filter_3_for_grayscale_alpha_8() {
 fn filter_4_for_grayscale_alpha_8() {
     test_it_converts(
         "tests/files/filter_4_for_grayscale_alpha_8.png",
-        FilterStrategy::PAETH,
+        RowFilter::Paeth,
         GRAYSCALE_ALPHA,
         BitDepth::Eight,
         GRAYSCALE_ALPHA,
@@ -483,7 +488,7 @@ fn filter_4_for_grayscale_alpha_8() {
 fn filter_5_for_grayscale_alpha_8() {
     test_it_converts(
         "tests/files/filter_5_for_grayscale_alpha_8.png",
-        FilterStrategy::MinSum,
+        RowFilter::MinSum,
         GRAYSCALE_ALPHA,
         BitDepth::Eight,
         GRAYSCALE_ALPHA,
@@ -495,7 +500,7 @@ fn filter_5_for_grayscale_alpha_8() {
 fn filter_0_for_grayscale_16() {
     test_it_converts(
         "tests/files/filter_0_for_grayscale_16.png",
-        FilterStrategy::NONE,
+        RowFilter::None,
         GRAYSCALE,
         BitDepth::Sixteen,
         GRAYSCALE,
@@ -507,7 +512,7 @@ fn filter_0_for_grayscale_16() {
 fn filter_1_for_grayscale_16() {
     test_it_converts(
         "tests/files/filter_1_for_grayscale_16.png",
-        FilterStrategy::SUB,
+        RowFilter::Sub,
         GRAYSCALE,
         BitDepth::Sixteen,
         GRAYSCALE,
@@ -519,7 +524,7 @@ fn filter_1_for_grayscale_16() {
 fn filter_2_for_grayscale_16() {
     test_it_converts(
         "tests/files/filter_2_for_grayscale_16.png",
-        FilterStrategy::UP,
+        RowFilter::Up,
         GRAYSCALE,
         BitDepth::Sixteen,
         GRAYSCALE,
@@ -531,7 +536,7 @@ fn filter_2_for_grayscale_16() {
 fn filter_3_for_grayscale_16() {
     test_it_converts(
         "tests/files/filter_3_for_grayscale_16.png",
-        FilterStrategy::AVERAGE,
+        RowFilter::Average,
         GRAYSCALE,
         BitDepth::Sixteen,
         GRAYSCALE,
@@ -543,7 +548,7 @@ fn filter_3_for_grayscale_16() {
 fn filter_4_for_grayscale_16() {
     test_it_converts(
         "tests/files/filter_4_for_grayscale_16.png",
-        FilterStrategy::PAETH,
+        RowFilter::Paeth,
         GRAYSCALE,
         BitDepth::Sixteen,
         GRAYSCALE,
@@ -555,7 +560,7 @@ fn filter_4_for_grayscale_16() {
 fn filter_5_for_grayscale_16() {
     test_it_converts(
         "tests/files/filter_5_for_grayscale_16.png",
-        FilterStrategy::MinSum,
+        RowFilter::MinSum,
         GRAYSCALE,
         BitDepth::Sixteen,
         GRAYSCALE,
@@ -567,7 +572,7 @@ fn filter_5_for_grayscale_16() {
 fn filter_0_for_grayscale_8() {
     test_it_converts(
         "tests/files/filter_0_for_grayscale_8.png",
-        FilterStrategy::NONE,
+        RowFilter::None,
         GRAYSCALE,
         BitDepth::Eight,
         GRAYSCALE,
@@ -579,7 +584,7 @@ fn filter_0_for_grayscale_8() {
 fn filter_1_for_grayscale_8() {
     test_it_converts(
         "tests/files/filter_1_for_grayscale_8.png",
-        FilterStrategy::SUB,
+        RowFilter::Sub,
         GRAYSCALE,
         BitDepth::Eight,
         GRAYSCALE,
@@ -591,7 +596,7 @@ fn filter_1_for_grayscale_8() {
 fn filter_2_for_grayscale_8() {
     test_it_converts(
         "tests/files/filter_2_for_grayscale_8.png",
-        FilterStrategy::UP,
+        RowFilter::Up,
         GRAYSCALE,
         BitDepth::Eight,
         GRAYSCALE,
@@ -603,7 +608,7 @@ fn filter_2_for_grayscale_8() {
 fn filter_3_for_grayscale_8() {
     test_it_converts(
         "tests/files/filter_3_for_grayscale_8.png",
-        FilterStrategy::AVERAGE,
+        RowFilter::Average,
         GRAYSCALE,
         BitDepth::Eight,
         GRAYSCALE,
@@ -615,7 +620,7 @@ fn filter_3_for_grayscale_8() {
 fn filter_4_for_grayscale_8() {
     test_it_converts(
         "tests/files/filter_4_for_grayscale_8.png",
-        FilterStrategy::PAETH,
+        RowFilter::Paeth,
         GRAYSCALE,
         BitDepth::Eight,
         GRAYSCALE,
@@ -627,7 +632,7 @@ fn filter_4_for_grayscale_8() {
 fn filter_5_for_grayscale_8() {
     test_it_converts(
         "tests/files/filter_5_for_grayscale_8.png",
-        FilterStrategy::MinSum,
+        RowFilter::MinSum,
         GRAYSCALE,
         BitDepth::Eight,
         GRAYSCALE,
@@ -639,7 +644,7 @@ fn filter_5_for_grayscale_8() {
 fn filter_0_for_palette_4() {
     test_it_converts(
         "tests/files/filter_0_for_palette_4.png",
-        FilterStrategy::NONE,
+        RowFilter::None,
         INDEXED,
         BitDepth::Four,
         INDEXED,
@@ -651,7 +656,7 @@ fn filter_0_for_palette_4() {
 fn filter_1_for_palette_4() {
     test_it_converts(
         "tests/files/filter_1_for_palette_4.png",
-        FilterStrategy::SUB,
+        RowFilter::Sub,
         INDEXED,
         BitDepth::Four,
         INDEXED,
@@ -663,7 +668,7 @@ fn filter_1_for_palette_4() {
 fn filter_2_for_palette_4() {
     test_it_converts(
         "tests/files/filter_2_for_palette_4.png",
-        FilterStrategy::UP,
+        RowFilter::Up,
         INDEXED,
         BitDepth::Four,
         INDEXED,
@@ -675,7 +680,7 @@ fn filter_2_for_palette_4() {
 fn filter_3_for_palette_4() {
     test_it_converts(
         "tests/files/filter_3_for_palette_4.png",
-        FilterStrategy::AVERAGE,
+        RowFilter::Average,
         INDEXED,
         BitDepth::Four,
         INDEXED,
@@ -687,7 +692,7 @@ fn filter_3_for_palette_4() {
 fn filter_4_for_palette_4() {
     test_it_converts(
         "tests/files/filter_4_for_palette_4.png",
-        FilterStrategy::PAETH,
+        RowFilter::Paeth,
         INDEXED,
         BitDepth::Four,
         INDEXED,
@@ -699,7 +704,7 @@ fn filter_4_for_palette_4() {
 fn filter_5_for_palette_4() {
     test_it_converts(
         "tests/files/filter_5_for_palette_4.png",
-        FilterStrategy::MinSum,
+        RowFilter::MinSum,
         INDEXED,
         BitDepth::Four,
         INDEXED,
@@ -711,7 +716,7 @@ fn filter_5_for_palette_4() {
 fn filter_0_for_palette_2() {
     test_it_converts(
         "tests/files/filter_0_for_palette_2.png",
-        FilterStrategy::NONE,
+        RowFilter::None,
         INDEXED,
         BitDepth::Two,
         INDEXED,
@@ -723,7 +728,7 @@ fn filter_0_for_palette_2() {
 fn filter_1_for_palette_2() {
     test_it_converts(
         "tests/files/filter_1_for_palette_2.png",
-        FilterStrategy::SUB,
+        RowFilter::Sub,
         INDEXED,
         BitDepth::Two,
         INDEXED,
@@ -735,7 +740,7 @@ fn filter_1_for_palette_2() {
 fn filter_2_for_palette_2() {
     test_it_converts(
         "tests/files/filter_2_for_palette_2.png",
-        FilterStrategy::UP,
+        RowFilter::Up,
         INDEXED,
         BitDepth::Two,
         INDEXED,
@@ -747,7 +752,7 @@ fn filter_2_for_palette_2() {
 fn filter_3_for_palette_2() {
     test_it_converts(
         "tests/files/filter_3_for_palette_2.png",
-        FilterStrategy::AVERAGE,
+        RowFilter::Average,
         INDEXED,
         BitDepth::Two,
         INDEXED,
@@ -759,7 +764,7 @@ fn filter_3_for_palette_2() {
 fn filter_4_for_palette_2() {
     test_it_converts(
         "tests/files/filter_4_for_palette_2.png",
-        FilterStrategy::PAETH,
+        RowFilter::Paeth,
         INDEXED,
         BitDepth::Two,
         INDEXED,
@@ -771,7 +776,7 @@ fn filter_4_for_palette_2() {
 fn filter_5_for_palette_2() {
     test_it_converts(
         "tests/files/filter_5_for_palette_2.png",
-        FilterStrategy::MinSum,
+        RowFilter::MinSum,
         INDEXED,
         BitDepth::Two,
         INDEXED,
@@ -783,7 +788,7 @@ fn filter_5_for_palette_2() {
 fn filter_0_for_palette_1() {
     test_it_converts(
         "tests/files/filter_0_for_palette_1.png",
-        FilterStrategy::NONE,
+        RowFilter::None,
         INDEXED,
         BitDepth::One,
         INDEXED,
@@ -795,7 +800,7 @@ fn filter_0_for_palette_1() {
 fn filter_1_for_palette_1() {
     test_it_converts(
         "tests/files/filter_1_for_palette_1.png",
-        FilterStrategy::SUB,
+        RowFilter::Sub,
         INDEXED,
         BitDepth::One,
         INDEXED,
@@ -807,7 +812,7 @@ fn filter_1_for_palette_1() {
 fn filter_2_for_palette_1() {
     test_it_converts(
         "tests/files/filter_2_for_palette_1.png",
-        FilterStrategy::UP,
+        RowFilter::Up,
         INDEXED,
         BitDepth::One,
         INDEXED,
@@ -819,7 +824,7 @@ fn filter_2_for_palette_1() {
 fn filter_3_for_palette_1() {
     test_it_converts(
         "tests/files/filter_3_for_palette_1.png",
-        FilterStrategy::AVERAGE,
+        RowFilter::Average,
         INDEXED,
         BitDepth::One,
         INDEXED,
@@ -831,7 +836,7 @@ fn filter_3_for_palette_1() {
 fn filter_4_for_palette_1() {
     test_it_converts(
         "tests/files/filter_4_for_palette_1.png",
-        FilterStrategy::PAETH,
+        RowFilter::Paeth,
         INDEXED,
         BitDepth::One,
         INDEXED,
@@ -843,7 +848,7 @@ fn filter_4_for_palette_1() {
 fn filter_5_for_palette_1() {
     test_it_converts(
         "tests/files/filter_5_for_palette_1.png",
-        FilterStrategy::MinSum,
+        RowFilter::MinSum,
         INDEXED,
         BitDepth::One,
         INDEXED,

tests/flags.rs

@@ -1,12 +1,13 @@
-use indexmap::indexset;
-use oxipng::{internal_tests::*, *};
-use serde_json::Value;
+#[cfg(feature = "zopfli")]
+use std::num::NonZeroU8;
 use std::{
     fs::remove_file,
     path::{Path, PathBuf},
-    process::Command,
 };
 
+use indexmap::indexset;
+use oxipng::{internal_tests::*, *};
+
 const GRAY: u8 = 0;
 const RGB: u8 = 2;
 const INDEXED: u8 = 3;
@@ -15,7 +16,7 @@ fn get_opts(input: &Path) -> (OutFile, Options) {
     let options = Options {
         force: true,
         fast_evaluation: false,
-        filters: indexset! {FilterStrategy::NONE},
+        filter: indexset! {RowFilter::None},
         ..Default::default()
     };
     (OutFile::from_path(input.with_extension("out.png")), options)
@@ -51,7 +52,7 @@ fn test_it_converts_callbacks<CBPRE, CBPOST>(
     match oxipng::optimize(&InFile::Path(input), output, opts) {
         Ok(_) => (),
         Err(x) => panic!("{}", x),
-    }
+    };
     let output = output.path().unwrap();
     assert!(output.exists());
 
@@ -96,9 +97,13 @@ fn test_it_converts(
 
 #[test]
 fn verbose_mode() {
-    use log::{Level, LevelFilter, Log, Metadata, Record, set_logger, set_max_level};
     use std::cell::RefCell;
-    use std::sync::mpsc::{Sender, channel};
+    #[cfg(not(feature = "parallel"))]
+    use std::sync::mpsc::{channel as unbounded, Sender};
+
+    #[cfg(feature = "parallel")]
+    use crossbeam_channel::{unbounded, Sender};
+    use log::{set_logger, set_max_level, Level, LevelFilter, Log, Metadata, Record};
 
     // Rust runs tests in parallel by default.
     // We want to make sure that we verify only logs from our test.
@@ -138,7 +143,7 @@ fn verbose_mode() {
     let input = PathBuf::from("tests/files/verbose_mode.png");
     let (output, opts) = get_opts(&input);
 
-    let (sender, receiver) = channel();
+    let (sender, receiver) = unbounded();
 
     let thread_init = move || {
         // Initialise logs storage for all threads within our test.
@@ -311,7 +316,7 @@ fn strip_chunks_none() {
 fn interlacing_0_to_1() {
     let input = PathBuf::from("tests/files/interlacing_0_to_1.png");
     let (output, mut opts) = get_opts(&input);
-    opts.interlace = Some(true);
+    opts.interlace = Some(Interlacing::Adam7);
 
     test_it_converts_callbacks(
         input,
@@ -322,10 +327,10 @@ fn interlacing_0_to_1() {
         RGB,
         BitDepth::Eight,
         |png| {
-            assert!(!png.raw.ihdr.interlaced);
+            assert_eq!(png.raw.ihdr.interlaced, Interlacing::None);
         },
         |png| {
-            assert!(png.raw.ihdr.interlaced);
+            assert_eq!(png.raw.ihdr.interlaced, Interlacing::Adam7);
         },
     );
 }
@@ -334,7 +339,7 @@ fn interlacing_0_to_1() {
 fn interlacing_1_to_0() {
     let input = PathBuf::from("tests/files/interlacing_1_to_0.png");
     let (output, mut opts) = get_opts(&input);
-    opts.interlace = Some(false);
+    opts.interlace = Some(Interlacing::None);
 
     test_it_converts_callbacks(
         input,
@@ -345,10 +350,10 @@ fn interlacing_1_to_0() {
         RGB,
         BitDepth::Eight,
         |png| {
-            assert!(png.raw.ihdr.interlaced);
+            assert_eq!(png.raw.ihdr.interlaced, Interlacing::Adam7);
         },
         |png| {
-            assert!(!png.raw.ihdr.interlaced);
+            assert_eq!(png.raw.ihdr.interlaced, Interlacing::None);
         },
     );
 }
@@ -357,7 +362,7 @@ fn interlacing_1_to_0() {
 fn interlacing_0_to_1_small_files() {
     let input = PathBuf::from("tests/files/interlacing_0_to_1_small_files.png");
     let (output, mut opts) = get_opts(&input);
-    opts.interlace = Some(true);
+    opts.interlace = Some(Interlacing::Adam7);
 
     test_it_converts_callbacks(
         input,
@@ -368,10 +373,10 @@ fn interlacing_0_to_1_small_files() {
         RGB,
         BitDepth::Eight,
         |png| {
-            assert!(!png.raw.ihdr.interlaced);
+            assert_eq!(png.raw.ihdr.interlaced, Interlacing::None);
         },
         |png| {
-            assert!(png.raw.ihdr.interlaced);
+            assert_eq!(png.raw.ihdr.interlaced, Interlacing::Adam7);
         },
     );
 }
@@ -380,7 +385,7 @@ fn interlacing_0_to_1_small_files() {
 fn interlacing_1_to_0_small_files() {
     let input = PathBuf::from("tests/files/interlacing_1_to_0_small_files.png");
     let (output, mut opts) = get_opts(&input);
-    opts.interlace = Some(false);
+    opts.interlace = Some(Interlacing::None);
 
     test_it_converts_callbacks(
         input,
@@ -391,10 +396,10 @@ fn interlacing_1_to_0_small_files() {
         RGB,
         BitDepth::Eight,
         |png| {
-            assert!(png.raw.ihdr.interlaced);
+            assert_eq!(png.raw.ihdr.interlaced, Interlacing::Adam7);
         },
         |png| {
-            assert!(!png.raw.ihdr.interlaced);
+            assert_eq!(png.raw.ihdr.interlaced, Interlacing::None);
         },
     );
 }
@@ -403,8 +408,8 @@ fn interlacing_1_to_0_small_files() {
 fn interlaced_0_to_1_other_filter_mode() {
     let input = PathBuf::from("tests/files/interlaced_0_to_1_other_filter_mode.png");
     let (output, mut opts) = get_opts(&input);
-    opts.interlace = Some(true);
-    opts.filters = indexset! {FilterStrategy::PAETH};
+    opts.interlace = Some(Interlacing::Adam7);
+    opts.filter = indexset! {RowFilter::Paeth};
 
     test_it_converts_callbacks(
         input,
@@ -415,10 +420,10 @@ fn interlaced_0_to_1_other_filter_mode() {
         GRAY,
         BitDepth::Sixteen,
         |png| {
-            assert!(!png.raw.ihdr.interlaced);
+            assert_eq!(png.raw.ihdr.interlaced, Interlacing::None);
         },
         |png| {
-            assert!(png.raw.ihdr.interlaced);
+            assert_eq!(png.raw.ihdr.interlaced, Interlacing::Adam7);
         },
     );
 }
@@ -427,9 +432,14 @@ fn interlaced_0_to_1_other_filter_mode() {
 fn preserve_attrs() {
     let input = PathBuf::from("tests/files/preserve_attrs.png");
 
+    #[cfg(feature = "filetime")]
     let meta_input = input
         .metadata()
-        .expect("unable to get metadata for input file");
+        .expect("unable to get file metadata for output file");
+    #[cfg(feature = "filetime")]
+    let atime_canon = filetime::FileTime::from_last_access_time(&meta_input);
+    #[cfg(feature = "filetime")]
+    let mtime_canon = filetime::FileTime::from_last_modification_time(&meta_input);
 
     let (mut output, opts) = get_opts(&input);
     if let OutFile::Path { preserve_attrs, .. } = &mut output {
@@ -439,10 +449,27 @@ fn preserve_attrs() {
     match oxipng::optimize(&InFile::Path(input), &output, &opts) {
         Ok(_) => (),
         Err(x) => panic!("{}", x),
-    }
+    };
     let output = output.path().unwrap();
     assert!(output.exists());
 
+    #[cfg(feature = "filetime")]
+    let meta_output = output
+        .metadata()
+        .expect("unable to get file metadata for output file");
+    #[cfg(feature = "filetime")]
+    assert_eq!(
+        &atime_canon,
+        &filetime::FileTime::from_last_access_time(&meta_output),
+        "expected access time to be identical to that of input",
+    );
+    #[cfg(feature = "filetime")]
+    assert_eq!(
+        &mtime_canon,
+        &filetime::FileTime::from_last_modification_time(&meta_output),
+        "expected modification time to be identical to that of input",
+    );
+
     match PngData::new(output, &opts) {
         Ok(x) => x,
         Err(x) => {
@@ -451,21 +478,9 @@ fn preserve_attrs() {
         }
     };
 
-    let meta_output = output
-        .metadata()
-        .expect("unable to get metadata for output file");
-    assert_eq!(
-        meta_input.modified().ok(),
-        meta_output.modified().ok(),
-        "expected modification time to be identical to that of input",
-    );
-    assert_eq!(
-        meta_input.permissions(),
-        meta_output.permissions(),
-        "expected permissions to be identical to that of input",
-    );
-
     remove_file(output).ok();
+
+    // TODO: Actually check permissions
 }
 
 #[test]
@@ -629,25 +644,14 @@ fn scale_16() {
     );
 }
 
-#[test]
-fn max_size() {
-    let result = oxipng::optimize(
-        &"tests/files/max_size.png".into(),
-        &OutFile::None,
-        &Options {
-            max_decompressed_size: Some(150_000),
-            ..Options::default()
-        },
-    );
-    assert!(matches!(result, Err(PngError::InflatedDataTooLong(_))));
-}
-
 #[test]
 #[cfg(feature = "zopfli")]
 fn zopfli_mode() {
     let input = PathBuf::from("tests/files/zopfli_mode.png");
     let (output, mut opts) = get_opts(&input);
-    opts.deflater = Deflater::Zopfli(ZopfliOptions::default());
+    opts.deflate = Deflaters::Zopfli {
+        iterations: NonZeroU8::new(15).unwrap(),
+    };
 
     test_it_converts(
         input,
@@ -659,39 +663,3 @@ fn zopfli_mode() {
         BitDepth::Eight,
     );
 }
-#[test]
-fn json_success() {
-    let path = "tests/files/json.png";
-    let output = Command::new(env!("CARGO_BIN_EXE_oxipng"))
-        .args(["--json", "--nx", "--nz", path])
-        .output()
-        .expect("Failed to run executable");
-    assert!(output.status.success());
-    let stdout = String::from_utf8_lossy(&output.stdout);
-    let data: Value = serde_json::from_str(&stdout).expect("Failed to parse JSON");
-    let result = &data["results"][0];
-    assert_eq!(result["input"], path);
-    assert_eq!(result["status"], "success");
-    assert_eq!(result["output"], path);
-    assert_eq!(result["insize"], result["outsize"]);
-}
-
-#[test]
-fn json_dry_run() {
-    let path = "tests/files/json.png";
-    let path2 = "tests/files/escape chars \\ \" \n \t \r \x08 \x0c.png";
-    let output = Command::new(env!("CARGO_BIN_EXE_oxipng"))
-        .args(["--json", "--dry-run", path, path2])
-        .output()
-        .expect("Failed to run executable");
-    assert!(output.status.success());
-    let stdout = String::from_utf8_lossy(&output.stdout);
-    let data: Value = serde_json::from_str(&stdout).expect("Failed to parse JSON");
-    let result = &data["results"][0];
-    assert_eq!(result["input"], path);
-    assert_eq!(result["status"], "success");
-    assert_eq!(result["output"], Value::Null);
-    let result2 = &data["results"][1];
-    assert_eq!(result2["input"], path2);
-    assert_eq!(result2["status"], "error");
-}

tests/interlaced.rs

@@ -12,13 +12,16 @@ const GRAYSCALE_ALPHA: u8 = 4;
 const RGBA: u8 = 6;
 
 fn get_opts(input: &Path) -> (OutFile, oxipng::Options) {
-    let options = oxipng::Options {
+    let mut options = oxipng::Options {
         force: true,
         fast_evaluation: false,
-        filters: indexset! {FilterStrategy::NONE},
         interlace: None,
         ..Default::default()
     };
+    let mut filter = IndexSet::new();
+    filter.insert(RowFilter::None);
+    options.filter = filter;
+
     (OutFile::from_path(input.with_extension("out.png")), options)
 }
 
@@ -35,12 +38,12 @@ fn test_it_converts(
 
     assert_eq!(png.raw.ihdr.color_type.png_header_code(), color_type_in);
     assert_eq!(png.raw.ihdr.bit_depth, bit_depth_in);
-    assert!(png.raw.ihdr.interlaced);
+    assert_eq!(png.raw.ihdr.interlaced, Interlacing::Adam7);
 
     match oxipng::optimize(&InFile::Path(input), &output, &opts) {
         Ok(_) => (),
         Err(x) => panic!("{}", x),
-    }
+    };
     let output = output.path().unwrap();
     assert!(output.exists());
 

tests/interlacing.rs

@@ -9,17 +9,20 @@ const RGB: u8 = 2;
 const INDEXED: u8 = 3;
 
 fn get_opts(input: &Path) -> (OutFile, oxipng::Options) {
-    let options = oxipng::Options {
+    let mut options = oxipng::Options {
         force: true,
-        filters: indexset! {FilterStrategy::NONE},
         ..Default::default()
     };
+    let mut filter = IndexSet::new();
+    filter.insert(RowFilter::None);
+    options.filter = filter;
+
     (OutFile::from_path(input.with_extension("out.png")), options)
 }
 
 fn test_it_converts(
     input: &str,
-    interlace: bool,
+    interlace: Interlacing,
     color_type_in: u8,
     bit_depth_in: BitDepth,
     color_type_out: u8,
@@ -31,12 +34,19 @@ fn test_it_converts(
     opts.interlace = Some(interlace);
     assert_eq!(png.raw.ihdr.color_type.png_header_code(), color_type_in);
     assert_eq!(png.raw.ihdr.bit_depth, bit_depth_in);
-    assert_eq!(png.raw.ihdr.interlaced, !interlace);
+    assert_eq!(
+        png.raw.ihdr.interlaced,
+        if interlace == Interlacing::Adam7 {
+            Interlacing::None
+        } else {
+            Interlacing::Adam7
+        }
+    );
 
     match oxipng::optimize(&InFile::Path(input), &output, &opts) {
         Ok(_) => (),
         Err(x) => panic!("{}", x),
-    }
+    };
     let output = output.path().unwrap();
     assert!(output.exists());
 
@@ -58,7 +68,7 @@ fn test_it_converts(
 fn deinterlace_rgb_16() {
     test_it_converts(
         "tests/files/interlaced_rgb_16_should_be_rgb_16.png",
-        false,
+        Interlacing::None,
         RGB,
         BitDepth::Sixteen,
         RGB,
@@ -70,7 +80,7 @@ fn deinterlace_rgb_16() {
 fn deinterlace_rgb_8() {
     test_it_converts(
         "tests/files/interlaced_rgb_8_should_be_rgb_8.png",
-        false,
+        Interlacing::None,
         RGB,
         BitDepth::Eight,
         RGB,
@@ -82,7 +92,7 @@ fn deinterlace_rgb_8() {
 fn deinterlace_palette_8() {
     test_it_converts(
         "tests/files/interlaced_palette_8_should_be_palette_8.png",
-        false,
+        Interlacing::None,
         INDEXED,
         BitDepth::Eight,
         INDEXED,
@@ -94,7 +104,7 @@ fn deinterlace_palette_8() {
 fn deinterlace_palette_4() {
     test_it_converts(
         "tests/files/interlaced_palette_4_should_be_palette_4.png",
-        false,
+        Interlacing::None,
         INDEXED,
         BitDepth::Four,
         INDEXED,
@@ -106,7 +116,7 @@ fn deinterlace_palette_4() {
 fn deinterlace_palette_2() {
     test_it_converts(
         "tests/files/interlaced_palette_2_should_be_palette_2.png",
-        false,
+        Interlacing::None,
         INDEXED,
         BitDepth::Two,
         INDEXED,
@@ -118,7 +128,7 @@ fn deinterlace_palette_2() {
 fn deinterlace_palette_1() {
     test_it_converts(
         "tests/files/interlaced_palette_1_should_be_palette_1.png",
-        false,
+        Interlacing::None,
         INDEXED,
         BitDepth::One,
         INDEXED,
@@ -130,7 +140,7 @@ fn deinterlace_palette_1() {
 fn interlace_rgb_16() {
     test_it_converts(
         "tests/files/rgb_16_should_be_rgb_16.png",
-        true,
+        Interlacing::Adam7,
         RGB,
         BitDepth::Sixteen,
         RGB,
@@ -142,7 +152,7 @@ fn interlace_rgb_16() {
 fn interlace_rgb_8() {
     test_it_converts(
         "tests/files/rgb_8_should_be_rgb_8.png",
-        true,
+        Interlacing::Adam7,
         RGB,
         BitDepth::Eight,
         RGB,
@@ -154,7 +164,7 @@ fn interlace_rgb_8() {
 fn interlace_palette_8() {
     test_it_converts(
         "tests/files/palette_8_should_be_palette_8.png",
-        true,
+        Interlacing::Adam7,
         INDEXED,
         BitDepth::Eight,
         INDEXED,
@@ -166,7 +176,7 @@ fn interlace_palette_8() {
 fn interlace_palette_4() {
     test_it_converts(
         "tests/files/palette_4_should_be_palette_4.png",
-        true,
+        Interlacing::Adam7,
         INDEXED,
         BitDepth::Four,
         INDEXED,
@@ -178,7 +188,7 @@ fn interlace_palette_4() {
 fn interlace_palette_2() {
     test_it_converts(
         "tests/files/palette_2_should_be_palette_2.png",
-        true,
+        Interlacing::Adam7,
         INDEXED,
         BitDepth::Two,
         INDEXED,
@@ -190,7 +200,7 @@ fn interlace_palette_2() {
 fn interlace_palette_1() {
     test_it_converts(
         "tests/files/palette_1_should_be_palette_1.png",
-        true,
+        Interlacing::Adam7,
         INDEXED,
         BitDepth::One,
         INDEXED,

tests/raw.rs

@@ -5,7 +5,7 @@ use oxipng::{internal_tests::*, *};
 fn get_opts() -> Options {
     Options {
         force: true,
-        filters: indexset! {FilterStrategy::NONE},
+        filter: indexset! { RowFilter::None },
         ..Default::default()
     }
 }

tests/reduction.rs

@@ -12,12 +12,15 @@ const GRAYSCALE_ALPHA: u8 = 4;
 const RGBA: u8 = 6;
 
 fn get_opts(input: &Path) -> (OutFile, oxipng::Options) {
-    let options = oxipng::Options {
+    let mut options = oxipng::Options {
         force: true,
         fast_evaluation: false,
-        filters: indexset! {FilterStrategy::NONE},
         ..Default::default()
     };
+    let mut filter = IndexSet::new();
+    filter.insert(RowFilter::None);
+    options.filter = filter;
+
     (OutFile::from_path(input.with_extension("out.png")), options)
 }
 
@@ -36,12 +39,12 @@ fn test_it_converts(
 
     assert_eq!(png.raw.ihdr.color_type.png_header_code(), color_type_in);
     assert_eq!(png.raw.ihdr.bit_depth, bit_depth_in, "test file is broken");
-    assert!(!png.raw.ihdr.interlaced);
+    assert_eq!(png.raw.ihdr.interlaced, Interlacing::None);
 
     match oxipng::optimize(&InFile::Path(input), &output, &opts) {
         Ok(_) => (),
         Err(x) => panic!("{}", x),
-    }
+    };
     let output = output.path().unwrap();
     assert!(output.exists());
 
@@ -999,7 +1002,7 @@ fn palette_should_be_reduced_with_dupes() {
     match oxipng::optimize(&InFile::Path(input), &output, &opts) {
         Ok(_) => (),
         Err(x) => panic!("{}", x),
-    }
+    };
     let output = output.path().unwrap();
     assert!(output.exists());
 
@@ -1036,7 +1039,7 @@ fn palette_should_be_reduced_with_unused() {
     match oxipng::optimize(&InFile::Path(input), &output, &opts) {
         Ok(_) => (),
         Err(x) => panic!("{}", x),
-    }
+    };
     let output = output.path().unwrap();
     assert!(output.exists());
 
@@ -1074,7 +1077,7 @@ fn palette_should_be_reduced_with_bkgd() {
     match oxipng::optimize(&InFile::Path(input), &output, &opts) {
         Ok(_) => (),
         Err(x) => panic!("{}", x),
-    }
+    };
     let output = output.path().unwrap();
     assert!(output.exists());
 
@@ -1112,7 +1115,7 @@ fn palette_should_be_reduced_with_both() {
     match oxipng::optimize(&InFile::Path(input), &output, &opts) {
         Ok(_) => (),
         Err(x) => panic!("{}", x),
-    }
+    };
     let output = output.path().unwrap();
     assert!(output.exists());
 
@@ -1149,7 +1152,7 @@ fn palette_should_be_reduced_with_missing() {
     match oxipng::optimize(&InFile::Path(input), &output, &opts) {
         Ok(_) => (),
         Err(x) => panic!("{}", x),
-    }
+    };
     let output = output.path().unwrap();
     assert!(output.exists());
 

tests/regression.rs

@@ -12,11 +12,14 @@ const GRAYSCALE_ALPHA: u8 = 4;
 const RGBA: u8 = 6;
 
 fn get_opts(input: &Path) -> (OutFile, oxipng::Options) {
-    let options = oxipng::Options {
+    let mut options = oxipng::Options {
         force: true,
-        filters: indexset! {FilterStrategy::NONE},
         ..Default::default()
     };
+    let mut filter = IndexSet::new();
+    filter.insert(RowFilter::None);
+    options.filter = filter;
+
     (OutFile::from_path(input.with_extension("out.png")), options)
 }
 
@@ -42,7 +45,7 @@ fn test_it_converts(
     match oxipng::optimize(&InFile::Path(input), &output, &opts) {
         Ok(_) => (),
         Err(x) => panic!("{}", x),
-    }
+    };
     let output = output.path().unwrap();
     assert!(output.exists());
 
@@ -75,7 +78,7 @@ fn test_it_converts(
 fn issue_42() {
     let input = "tests/files/issue-42.png";
     let (output, mut opts) = get_opts(Path::new(input));
-    opts.interlace = Some(true);
+    opts.interlace = Some(Interlacing::Adam7);
     test_it_converts(
         input,
         Some((output, opts)),
@@ -186,7 +189,7 @@ fn issue_175() {
 fn issue_182() {
     let input = "tests/files/issue-182.png";
     let (output, mut opts) = get_opts(Path::new(input));
-    opts.interlace = Some(true);
+    opts.interlace = Some(Interlacing::Adam7);
 
     test_it_converts(
         input,

tests/strategies.rs

@@ -11,16 +11,20 @@ const INDEXED: u8 = 3;
 const RGBA: u8 = 6;
 
 fn get_opts(input: &Path) -> (OutFile, oxipng::Options) {
-    let options = oxipng::Options {
+    let mut options = oxipng::Options {
         force: true,
         ..Default::default()
     };
+    let mut filter = IndexSet::new();
+    filter.insert(RowFilter::None);
+    options.filter = filter;
+
     (OutFile::from_path(input.with_extension("out.png")), options)
 }
 
 fn test_it_converts(
     input: &str,
-    filter: FilterStrategy,
+    filter: RowFilter,
     color_type_in: u8,
     bit_depth_in: BitDepth,
     color_type_out: u8,
@@ -30,14 +34,15 @@ fn test_it_converts(
 
     let (output, mut opts) = get_opts(&input);
     let png = PngData::new(&input, &opts).unwrap();
-    opts.filters = indexset! {filter};
+    opts.filter = IndexSet::new();
+    opts.filter.insert(filter);
     assert_eq!(png.raw.ihdr.color_type.png_header_code(), color_type_in);
     assert_eq!(png.raw.ihdr.bit_depth, bit_depth_in);
 
     match oxipng::optimize(&InFile::Path(input), &output, &opts) {
         Ok(_) => (),
         Err(x) => panic!("{}", x),
-    }
+    };
     let output = output.path().unwrap();
     assert!(output.exists());
 
@@ -62,7 +67,7 @@ fn test_it_converts(
 fn filter_minsum() {
     test_it_converts(
         "tests/files/rgb_16_should_be_rgb_16.png",
-        FilterStrategy::MinSum,
+        RowFilter::MinSum,
         RGB,
         BitDepth::Sixteen,
         RGB,
@@ -74,7 +79,7 @@ fn filter_minsum() {
 fn filter_entropy() {
     test_it_converts(
         "tests/files/rgb_8_should_be_rgb_8.png",
-        FilterStrategy::Entropy,
+        RowFilter::Entropy,
         RGB,
         BitDepth::Eight,
         RGB,
@@ -86,7 +91,7 @@ fn filter_entropy() {
 fn filter_bigrams() {
     test_it_converts(
         "tests/files/rgba_8_should_be_rgba_8.png",
-        FilterStrategy::Bigrams,
+        RowFilter::Bigrams,
         RGBA,
         BitDepth::Eight,
         RGBA,
@@ -98,7 +103,7 @@ fn filter_bigrams() {
 fn filter_bigent() {
     test_it_converts(
         "tests/files/grayscale_8_should_be_grayscale_8.png",
-        FilterStrategy::BigEnt,
+        RowFilter::BigEnt,
         GRAYSCALE,
         BitDepth::Eight,
         GRAYSCALE,
@@ -110,10 +115,7 @@ fn filter_bigent() {
 fn filter_brute() {
     test_it_converts(
         "tests/files/palette_8_should_be_palette_8.png",
-        FilterStrategy::Brute {
-            num_lines: 4,
-            level: 1,
-        },
+        RowFilter::Brute,
         INDEXED,
         BitDepth::Eight,
         INDEXED,

xtask/Cargo.lock

@@ -1,6 +1,6 @@
 # This file is automatically @generated by Cargo.
 # It is not intended for manual editing.
-version = 4
+version = 3
 
 [[package]]
 name = "anstream"
@@ -100,12 +100,6 @@ version = "1.70.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "7943c866cc5cd64cbc25b2e01621d07fa8eb2a1a23160ee81ce38704e97b8ecf"
 
-[[package]]
-name = "parse-size"
-version = "1.1.0"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "487f2ccd1e17ce8c1bfab3a65c89525af41cfad4c8659021a1e9a2aacd73b89b"
-
 [[package]]
 name = "roff"
 version = "0.2.2"
@@ -203,5 +197,4 @@ version = "0.1.0"
 dependencies = [
  "clap",
  "clap_mangen",
- "parse-size",
 ]

xtask/Cargo.toml

@@ -8,4 +8,3 @@ publish = false
 [dependencies]
 clap = "4.5.21"
 clap_mangen = "0.2.24"
-parse-size = "1.1.0"