chore(deps): bump the rust-dependencies group with 2 updates (#818)

Signed-off-by: dependabot[bot] <support@github.com>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

.dockerignore

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

.github/workflows/deploy.yml

@@ -3,7 +3,12 @@ name: deploy
 on:
   push:
     tags:
-      - "v*.*.*"
+      - 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
 
 permissions:
   actions: read
@@ -54,15 +59,15 @@ jobs:
 
       - name: Get the Oxipng version
         id: oxipngMeta
-        run:
+        run: >
-          echo "version=$(cargo metadata --format-version 1 --no-deps | jq -r '.packages[] | select(.name == "oxipng").version')"
+          echo "version=$(cargo metadata --format-version 1 --no-deps |
-          >> "$GITHUB_OUTPUT"
+          jq -r '.packages[] | select(.name == "oxipng").version')" >> "$GITHUB_OUTPUT"
 
       - name: Retrieve ${{ matrix.target }} binary
-        uses: dawidd6/action-download-artifact@v12
+        uses: dawidd6/action-download-artifact@v21
         with:
           workflow: oxipng.yml
-          commit: ${{ env.GITHUB_SHA }}
+          commit: ${{ github.sha }}
           name: Oxipng binary (${{ matrix.target }})
           path: target
 
@@ -123,7 +128,7 @@ jobs:
         run: tail -n +3 CHANGELOG.md | sed -e '/^$/,$d' > RELEASE_NOTES.txt
 
       - name: Create release
-        uses: softprops/action-gh-release@v2
+        uses: softprops/action-gh-release@v3
         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
@@ -17,76 +17,44 @@ on:
         type: boolean
         default: true
 
-env:
+concurrency:
-  REGISTRY: ghcr.io
+  # If we ever end up with two concurrent Docker build jobs for the same commit
-  # ghcr.io/OWNER/REPO
+  # and same versioning context, the former should be cancelled
-  IMAGE_NAME: ${{ github.repository }}
+  group: docker-${{ github.sha }}-${{ github.ref_type }}-${{ github.head_ref }}
+  cancel-in-progress: true
 
 jobs:
   build:
-    runs-on: ubuntu-latest
+    uses: docker/github-builder/.github/workflows/build.yml@v1
     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
 
-    steps:
+    secrets:
-      - name: Checkout repository
+      registry-auths: |
-        uses: actions/checkout@v6
+        - registry: ghcr.io
-
-      - 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@v3
-        with:
-          subject-name: ${{ env.REGISTRY }}/${{ env.IMAGE_NAME }}
-          subject-digest: ${{ steps.build-and-push.outputs.digest }}
-          push-to-registry: false

.github/workflows/oxipng.yml

@@ -8,6 +8,11 @@ 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
@@ -55,7 +60,6 @@ jobs:
 
     env:
       CARGO_BUILD_TARGET: ${{ matrix.target }}
-      RUSTFLAGS: '-Zlocation-detail=none'
 
     steps:
       - name: Checkout source
@@ -74,7 +78,7 @@ jobs:
         with:
           toolchain: nightly
           target: ${{ env.CARGO_BUILD_TARGET }}
-          components: clippy, rustfmt
+          components: clippy, rustfmt, rust-src
           cache-bin: false
           cache-shared-key: cache
 
@@ -125,10 +129,12 @@ jobs:
         run: cargo doc --release --no-deps
 
       - name: Build CLI binary
-        run: cargo build --release
+        run: cargo build --release -Zbuild-std
+        env:
+          RUSTFLAGS: "-Zlocation-detail=none -Zunstable-options -Cpanic=immediate-abort"
 
       - name: Upload CLI binary as artifact
-        uses: actions/upload-artifact@v6
+        uses: actions/upload-artifact@v7
         with:
           name: Oxipng binary (${{ matrix.target }})
           path: |

.gitignore

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

CHANGELOG.md

@@ -1,3 +1,11 @@
+## 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.
@@ -7,7 +15,7 @@
 ## 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 `--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>`.

Cargo.lock

@@ -10,9 +10,9 @@ checksum = "320119579fcad9c21884f5c4861d16174d0e06250625266f50fe6898340abefa"
 
 [[package]]
 name = "anstream"
-version = "0.6.20"
+version = "1.0.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "3ae563653d1938f79b1ab1b5e668c87c76a9930414574a6583a7b7e11a8e6192"
+checksum = "824a212faf96e9acacdbd09febd34438f8f711fb84e09a8916013cd7815ca28d"
 dependencies = [
  "anstyle",
  "anstyle-parse",
@@ -25,37 +25,37 @@ dependencies = [
 
 [[package]]
 name = "anstyle"
-version = "1.0.11"
+version = "1.0.14"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "862ed96ca487e809f1c8e5a8447f6ee2cf102f846893800b20cebdf541fc6bbd"
+checksum = "940b3a0ca603d1eade50a4846a2afffd5ef57a9feac2c0e2ec2e14f9ead76000"
 
 [[package]]
 name = "anstyle-parse"
-version = "0.2.7"
+version = "1.0.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "4e7644824f0aa2c7b9384579234ef10eb7efb6a0deb83f9630a49594dd9c15c2"
+checksum = "52ce7f38b242319f7cabaa6813055467063ecdc9d355bbb4ce0c68908cd8130e"
 dependencies = [
  "utf8parse",
 ]
 
 [[package]]
 name = "anstyle-query"
-version = "1.1.4"
+version = "1.1.5"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "9e231f6134f61b71076a3eab506c379d4f36122f2af15a9ff04415ea4c3339e2"
+checksum = "40c48f72fd53cd289104fc64099abca73db4166ad86ea0b4341abe65af83dadc"
 dependencies = [
- "windows-sys 0.60.2",
+ "windows-sys",
 ]
 
 [[package]]
 name = "anstyle-wincon"
-version = "3.0.10"
+version = "3.0.11"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "3e0633414522a32ffaac8ac6cc8f748e090c5717661fddeea04219e2344f5f2a"
+checksum = "291e6a250ff86cd4a820112fb8898808a366d8f9f58ce16d1f538353ad55747d"
 dependencies = [
  "anstyle",
  "once_cell_polyfill",
- "windows-sys 0.60.2",
+ "windows-sys",
 ]
 
 [[package]]
@@ -66,9 +66,9 @@ checksum = "c08606f8c3cbf4ce6ec8e28fb0014a2c086708fe954eaa885384a6165172e7e8"
 
 [[package]]
 name = "bitflags"
-version = "2.9.4"
+version = "2.11.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "2261d10cca569e4643e526d8dc2e62e433cc8aba21ab764233731f8d369bf394"
+checksum = "c4512299f36f043ab09a583e57bceb5a5aab7a73db1805848e8fef3c9e8c78b3"
 
 [[package]]
 name = "bitvec"
@@ -84,15 +84,15 @@ dependencies = [
 
 [[package]]
 name = "bumpalo"
-version = "3.19.0"
+version = "3.20.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "46c5e41b57b8bba42a04676d81cb89e9ee8e859a1a66f80a5a72e1cb76b34d43"
+checksum = "5d20789868f4b01b2f2caec9f5c4e0213b41e3e5702a50157d699ae31ced2fcb"
 
 [[package]]
 name = "bytemuck"
-version = "1.23.2"
+version = "1.25.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "3995eaeebcdf32f91f980d360f78732ddc061097ab4e39991ae7a6ace9194677"
+checksum = "c8efb64bd706a16a1bdde310ae86b351e4d21550d98d056f22f8a7f7a2183fec"
 
 [[package]]
 name = "byteorder-lite"
@@ -102,9 +102,9 @@ checksum = "8f1fe948ff07f4bd06c30984e69f5b4899c516a3ef74f34df92a2df2ab535495"
 
 [[package]]
 name = "cc"
-version = "1.2.38"
+version = "1.2.60"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "80f41ae168f955c12fb8960b057d70d0ca153fb83182b57d86380443527be7e9"
+checksum = "43c5703da9466b66a946814e1adf53ea2c90f10063b86290cc9eb67ce3478a20"
 dependencies = [
  "find-msvc-tools",
  "shlex",
@@ -112,24 +112,24 @@ dependencies = [
 
 [[package]]
 name = "cfg-if"
-version = "1.0.3"
+version = "1.0.4"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "2fd1289c04a9ea8cb22300a459a72a385d7c73d3259e2ed7dcb2af674838cfa9"
+checksum = "9330f8b2ff13f34540b44e946ef35111825727b38d33286ef986142615121801"
 
 [[package]]
 name = "clap"
-version = "4.5.54"
+version = "4.6.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "c6e6ff9dcd79cff5cd969a17a545d79e84ab086e444102a591e288a8aa3ce394"
+checksum = "1ddb117e43bbf7dacf0a4190fef4d345b9bad68dfc649cb349e7d17d28428e51"
 dependencies = [
  "clap_builder",
 ]
 
 [[package]]
 name = "clap_builder"
-version = "4.5.54"
+version = "4.6.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "fa42cf4d2b7a41bc8f663a7cab4031ebafa1bf3875705bfaf8466dc60ab52c00"
+checksum = "714a53001bf66416adb0e2ef5ac857140e7dc3a0c48fb28b2f10762fc4b5069f"
 dependencies = [
  "anstream",
  "anstyle",
@@ -140,15 +140,15 @@ dependencies = [
 
 [[package]]
 name = "clap_lex"
-version = "0.7.5"
+version = "1.1.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "b94f61472cee1439c0b966b47e3aca9ae07e45d070759512cd390ea2bebc6675"
+checksum = "c8d4a3bb8b1e0c1050499d1815f5ab16d04f0959b233085fb31653fbfc9d98f9"
 
 [[package]]
 name = "colorchoice"
-version = "1.0.4"
+version = "1.0.5"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "b05b61dc5112cbb17e4b6cd61790d9845d13888356391624cbe7e41efeac1e75"
+checksum = "1d07550c9036bf2ae0c684c4297d503f838287c83c53686d05370d0e139ae570"
 
 [[package]]
 name = "crc32fast"
@@ -159,15 +159,6 @@ 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"
@@ -201,18 +192,18 @@ checksum = "48c757948c5ede0e46177b7add2e67155f70e33c07fea8284df6576da70b3719"
 
 [[package]]
 name = "env_filter"
-version = "0.1.3"
+version = "1.0.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "186e05a59d4c50738528153b83b0b0194d3a29507dfec16eccd4b342903397d0"
+checksum = "32e90c2accc4b07a8456ea0debdc2e7587bdd890680d71173a15d4ae604f6eef"
 dependencies = [
  "log",
 ]
 
 [[package]]
 name = "env_logger"
-version = "0.11.8"
+version = "0.11.10"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "13c863f0904021b108aa8b2f55046443e6b1ebde8fd4a15c399893aae4fa069f"
+checksum = "0621c04f2196ac3f488dd583365b9c09be011a4ab8b9f37248ffcc8f6198b56a"
 dependencies = [
  "anstream",
  "anstyle",
@@ -233,7 +224,7 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "39cab71617ae0d63f51a36d69f866391735b51691dbda63cf6f96d042b63efeb"
 dependencies = [
  "libc",
- "windows-sys 0.61.0",
+ "windows-sys",
 ]
 
 [[package]]
@@ -247,15 +238,15 @@ dependencies = [
 
 [[package]]
 name = "find-msvc-tools"
-version = "0.1.2"
+version = "0.1.9"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "1ced73b1dacfc750a6db6c0a0c3a3853c8b41997e2e2c563dc90804ae6867959"
+checksum = "5baebc0774151f905a1a2cc41989300b1e6fbb29aff0ceffa1064fdd3088d582"
 
 [[package]]
 name = "flate2"
-version = "1.1.2"
+version = "1.1.9"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "4a3d7db9596fecd151c5f638c0ee5d5bd487b6e0ea232e5dc96d5250f6f94b1d"
+checksum = "843fba2746e448b37e26a819579957415c8cef339bf08564fe8b7ddbd959573c"
 dependencies = [
  "crc32fast",
  "miniz_oxide",
@@ -275,9 +266,9 @@ checksum = "0cc23270f6e1808e30a928bdc84dea0b9b4136a8bc82338574f23baf47bbd280"
 
 [[package]]
 name = "hashbrown"
-version = "0.16.1"
+version = "0.17.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "841d1cc9bed7f9236f321df977030373f4a4163ae1a7dbfe1a51a2c1a51d9100"
+checksum = "4f467dd6dccf739c208452f8014c75c18bb8301b050ad1cfb27153803edb0f51"
 
 [[package]]
 name = "image"
@@ -294,9 +285,9 @@ dependencies = [
 
 [[package]]
 name = "indexmap"
-version = "2.13.0"
+version = "2.14.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "7714e70437a7dc3ac8eb7e6f8df75fd8eb422675fc7678aff7364301092b1017"
+checksum = "d466e9454f08e4a911e14806c24e16fba1b4c121d1ea474396f396069cf949d9"
 dependencies = [
  "equivalent",
  "hashbrown",
@@ -305,27 +296,27 @@ dependencies = [
 
 [[package]]
 name = "is_terminal_polyfill"
-version = "1.70.1"
+version = "1.70.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "7943c866cc5cd64cbc25b2e01621d07fa8eb2a1a23160ee81ce38704e97b8ecf"
+checksum = "a6cb138bb79a146c1bd460005623e142ef0181e3d0219cb493e02f7d08a35695"
 
 [[package]]
 name = "itoa"
-version = "1.0.16"
+version = "1.0.18"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "7ee5b5339afb4c41626dde77b7a611bd4f2c202b897852b4bcf5d03eddc61010"
+checksum = "8f42a60cbdf9a97f5d2305f08a87dc4e09308d1276d28c869c684d7777685682"
 
 [[package]]
 name = "libc"
-version = "0.2.175"
+version = "0.2.185"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "6a82ae493e598baaea5209805c49bbf2ea7de956d50d7da0da1164f9c6d28543"
+checksum = "52ff2c0fe9bc6cb6b14a0592c2ff4fa9ceb83eea9db979b0487cd054946a2b8f"
 
 [[package]]
 name = "libdeflate-sys"
-version = "1.25.0"
+version = "1.25.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "23bd6304ebf75390d8a99b88bdf2a266f62647838140cb64af8e6702f6e3fddc"
+checksum = "72753e0008ea87963d2f0770042d0df7abe51fafbb8dcaf618ac440f2f1fec0a"
 dependencies = [
  "cc",
  "pkg-config",
@@ -333,30 +324,30 @@ dependencies = [
 
 [[package]]
 name = "libdeflater"
-version = "1.25.0"
+version = "1.25.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "d5d4880e6d634d3d029d65fa016038e788cc728a17b782684726fb34ee140caf"
+checksum = "d1ee41cf6fb1bb6030dfb59ffb7bc01ab26aade44142084c87f0fc7a1658fe71"
 dependencies = [
  "libdeflate-sys",
 ]
 
 [[package]]
 name = "linux-raw-sys"
-version = "0.11.0"
+version = "0.12.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "df1d3c3b53da64cf5760482273a98e575c651a67eec7f77df96b5b642de8f039"
+checksum = "32a66949e030da00e8c7d4434b251670a91556f4144941d37452769c25d58a53"
 
 [[package]]
 name = "log"
-version = "0.4.29"
+version = "0.4.30"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "5e5032e24019045c762d3c0f28f5b6b8bbf38563a65908389bf7978758920897"
+checksum = "616ec5685824bcc94416c6d4a7a446eea774a31efd7062c8480ba6fd06d7a6e5"
 
 [[package]]
 name = "memchr"
-version = "2.7.6"
+version = "2.8.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "f52b00d39961fc5b2736ea853c9cc86238e165017a493d1d5c8eac6bdc4cc273"
+checksum = "f8ca58f447f06ed17d5fc4043ce1b10dd205e060fb3ce5b979b8ed8e59ff3f79"
 
 [[package]]
 name = "miniz_oxide"
@@ -370,9 +361,9 @@ dependencies = [
 
 [[package]]
 name = "moxcms"
-version = "0.7.5"
+version = "0.7.11"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "ddd32fa8935aeadb8a8a6b6b351e40225570a37c43de67690383d87ef170cd08"
+checksum = "ac9557c559cd6fc9867e122e20d2cbefc9ca29d80d027a8e39310920ed2f0a97"
 dependencies = [
  "num-traits",
  "pxfm",
@@ -389,17 +380,16 @@ dependencies = [
 
 [[package]]
 name = "once_cell_polyfill"
-version = "1.70.1"
+version = "1.70.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "a4895175b425cb1f87721b59f0f286c2092bd4af812243672510e1ac53e2e0ad"
+checksum = "384b8ab6d37215f3c5301a95a4accb5d64aa607f1fcb26a11b5303878451b4fe"
 
 [[package]]
 name = "oxipng"
-version = "10.1.0"
+version = "10.1.1"
 dependencies = [
  "bitvec",
  "clap",
- "crossbeam-channel",
  "env_logger",
  "glob",
  "image",
@@ -422,15 +412,15 @@ checksum = "487f2ccd1e17ce8c1bfab3a65c89525af41cfad4c8659021a1e9a2aacd73b89b"
 
 [[package]]
 name = "pkg-config"
-version = "0.3.32"
+version = "0.3.33"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "7edddbd0b52d732b21ad9a5fab5c704c14cd949e5e9a1ec5929a24fded1b904c"
+checksum = "19f132c84eca552bf34cab8ec81f1c1dcc229b811638f9d283dceabe58c5569e"
 
 [[package]]
 name = "png"
-version = "0.18.0"
+version = "0.18.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "97baced388464909d42d89643fe4361939af9b7ce7a31ee32a168f832a70f2a0"
+checksum = "60769b8b31b2a9f263dae2776c37b1b28ae246943cf719eb6946a1db05128a61"
 dependencies = [
  "bitflags",
  "crc32fast",
@@ -441,27 +431,24 @@ dependencies = [
 
 [[package]]
 name = "proc-macro2"
-version = "1.0.103"
+version = "1.0.106"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "5ee95bc4ef87b8d5ba32e8b7714ccc834865276eab0aed5c9958d00ec45f49e8"
+checksum = "8fd00f0bb2e90d81d1044c2b32617f68fcb9fa3bb7640c23e9c748e53fb30934"
 dependencies = [
  "unicode-ident",
 ]
 
 [[package]]
 name = "pxfm"
-version = "0.1.24"
+version = "0.1.29"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "83f9b339b02259ada5c0f4a389b7fb472f933aa17ce176fd2ad98f28bb401fde"
+checksum = "e0c5ccf5294c6ccd63a74f1565028353830a9c2f5eb0c682c355c471726a6e3f"
-dependencies = [
- "num-traits",
-]
 
 [[package]]
 name = "quote"
-version = "1.0.42"
+version = "1.0.45"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "a338cc41d27e6cc6dce6cefc13a0729dfbb81c262b1f519331575dd80ef3067f"
+checksum = "41f2619966050689382d2b44f664f4bc593e129785a36d6ee376ddf37259b924"
 dependencies = [
  "proc-macro2",
 ]
@@ -474,9 +461,9 @@ checksum = "dc33ff2d4973d518d823d61aa239014831e521c75da58e3df4840d3f47749d09"
 
 [[package]]
 name = "rayon"
-version = "1.11.0"
+version = "1.12.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "368f01d005bf8fd9b1206fb6fa653e6c4a81ceb1466406b81792d87c5677a58f"
+checksum = "fb39b166781f92d482534ef4b4b1b2568f42613b53e5b6c160e24cfbfa30926d"
 dependencies = [
  "either",
  "rayon-core",
@@ -494,30 +481,30 @@ dependencies = [
 
 [[package]]
 name = "rgb"
-version = "0.8.52"
+version = "0.8.53"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "0c6a884d2998352bb4daf0183589aec883f16a6da1f4dde84d8e2e9a5409a1ce"
+checksum = "47b34b781b31e5d73e9fbc8689c70551fd1ade9a19e3e28cfec8580a79290cc4"
 dependencies = [
  "bytemuck",
 ]
 
 [[package]]
 name = "rustc-hash"
-version = "2.1.1"
+version = "2.1.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "357703d41365b4b27c590e3ed91eabb1b663f07c4c084095e60cbed4362dff0d"
+checksum = "94300abf3f1ae2e2b8ffb7b58043de3d399c73fa6f4b73826402a5c457614dbe"
 
 [[package]]
 name = "rustix"
-version = "1.1.2"
+version = "1.1.4"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "cd15f8a2c5551a84d56efdc1cd049089e409ac19a3072d5037a17fd70719ff3e"
+checksum = "b6fe4565b9518b83ef4f91bb47ce29620ca828bd32cb7e408f0062e9930ba190"
 dependencies = [
  "bitflags",
  "errno",
  "libc",
  "linux-raw-sys",
- "windows-sys 0.61.0",
+ "windows-sys",
 ]
 
 [[package]]
@@ -551,9 +538,9 @@ dependencies = [
 
 [[package]]
 name = "serde_json"
-version = "1.0.147"
+version = "1.0.150"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "6af14725505314343e673e9ecb7cd7e8a36aa9791eb936235a3567cc31447ae4"
+checksum = "e8014e44b4736ed0538adeecded0fce2a272f22dc9578a7eb6b2d9993c74cfb9"
 dependencies = [
  "itoa",
  "memchr",
@@ -570,9 +557,9 @@ checksum = "0fda2ff0d084019ba4d7c6f371c95d8fd75ce3524c3cb8fb653a3023f6323e64"
 
 [[package]]
 name = "simd-adler32"
-version = "0.3.7"
+version = "0.3.9"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "d66dc143e6b11c1eddc06d5c423cfc97062865baf299914ab64caa38182078fe"
+checksum = "703d5c7ef118737c72f1af64ad2f6f8c5e1921f818cdcb97b8fe6fc69bf66214"
 
 [[package]]
 name = "strsim"
@@ -582,9 +569,9 @@ checksum = "7da8b5736845d9f2fcb837ea5d9e2628564b3b043a70948a3f0b778838c5fb4f"
 
 [[package]]
 name = "syn"
-version = "2.0.111"
+version = "2.0.117"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "390cc9a294ab71bdb1aa2e99d13be9c753cd2d7bd6560c77118597410c4d2e87"
+checksum = "e665b8803e7b1d2a727f4023456bbbbe74da67099c585258af0ad9c5013b9b99"
 dependencies = [
  "proc-macro2",
  "quote",
@@ -599,19 +586,19 @@ checksum = "55937e1799185b12863d447f42597ed69d9928686b8d88a1df17376a097d8369"
 
 [[package]]
 name = "terminal_size"
-version = "0.4.3"
+version = "0.4.4"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "60b8cb979cb11c32ce1603f8137b22262a9d131aaa5c37b5678025f22b8becd0"
+checksum = "230a1b821ccbd75b185820a1f1ff7b14d21da1e442e22c0863ea5f08771a8874"
 dependencies = [
  "rustix",
- "windows-sys 0.60.2",
+ "windows-sys",
 ]
 
 [[package]]
 name = "unicode-ident"
-version = "1.0.22"
+version = "1.0.24"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "9312f7c4f6ff9069b165498234ce8be658059c6728633667c526e27dc2cf1df5"
+checksum = "e6e4313cd5fcd3dad5cafa179702e2b244f760991f45397d14d4ebf38247da75"
 
 [[package]]
 name = "utf8parse"
@@ -621,99 +608,19 @@ checksum = "06abde3611657adf66d383f00b093d7faecc7fa57071cce2578660c9f1010821"
 
 [[package]]
 name = "windows-link"
-version = "0.1.3"
+version = "0.2.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "5e6ad25900d524eaabdbbb96d20b4311e1e7ae1699af4fb28c17ae66c80d798a"
+checksum = "f0805222e57f7521d6a62e36fa9163bc891acd422f971defe97d64e70d0a4fe5"
-
-[[package]]
-name = "windows-link"
-version = "0.2.0"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "45e46c0661abb7180e7b9c281db115305d49ca1709ab8242adf09666d2173c65"
 
 [[package]]
 name = "windows-sys"
-version = "0.60.2"
+version = "0.61.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "f2f500e4d28234f72040990ec9d39e3a6b950f9f22d3dba18416c35882612bcb"
+checksum = "ae137229bcbd6cdf0f7b80a31df61766145077ddf49416a728b02cb3921ff3fc"
 dependencies = [
- "windows-targets",
+ "windows-link",
 ]
 
-[[package]]
-name = "windows-sys"
-version = "0.61.0"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "e201184e40b2ede64bc2ea34968b28e33622acdbbf37104f0e4a33f7abe657aa"
-dependencies = [
- "windows-link 0.2.0",
-]
-
-[[package]]
-name = "windows-targets"
-version = "0.53.3"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "d5fe6031c4041849d7c496a8ded650796e7b6ecc19df1a431c1a363342e5dc91"
-dependencies = [
- "windows-link 0.1.3",
- "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 = "0.53.0"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "86b8d5f90ddd19cb4a147a5fa63ca848db3df085e25fee3cc10b39b6eebae764"
-
-[[package]]
-name = "windows_aarch64_msvc"
-version = "0.53.0"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "c7651a1f62a11b8cbd5e0d42526e55f2c99886c77e007179efff86c2b137e66c"
-
-[[package]]
-name = "windows_i686_gnu"
-version = "0.53.0"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "c1dc67659d35f387f5f6c479dc4e28f1d4bb90ddd1a5d3da2e5d97b42d6272c3"
-
-[[package]]
-name = "windows_i686_gnullvm"
-version = "0.53.0"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "9ce6ccbdedbf6d6354471319e781c0dfef054c81fbc7cf83f338a4296c0cae11"
-
-[[package]]
-name = "windows_i686_msvc"
-version = "0.53.0"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "581fee95406bb13382d2f65cd4a908ca7b1e4c2f1917f143ba16efe98a589b5d"
-
-[[package]]
-name = "windows_x86_64_gnu"
-version = "0.53.0"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "2e55b5ac9ea33f2fc1716d1742db15574fd6fc8dadc51caab1c16a3d3b4190ba"
-
-[[package]]
-name = "windows_x86_64_gnullvm"
-version = "0.53.0"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "0a6e035dd0599267ce1ee132e51c27dd29437f63325753051e71dd9e42406c57"
-
-[[package]]
-name = "windows_x86_64_msvc"
-version = "0.53.0"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "271414315aff87387382ec3d271b52d7ae78726f5d44ac98b4f4030c91880486"
-
 [[package]]
 name = "wyz"
 version = "0.5.1"
@@ -725,9 +632,9 @@ dependencies = [
 
 [[package]]
 name = "zmij"
-version = "0.1.10"
+version = "1.0.21"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "4af59da1029247450b54ba43e0b62c8e376582464bbe5504dd525fe521e7e8fd"
+checksum = "b8848ee67ecc8aedbaf3e4122217aff892639231befc6a1b58d29fff4c2cabaa"
 
 [[package]]
 name = "zopfli"

Cargo.toml

@@ -20,7 +20,7 @@ homepage = "https://github.com/oxipng/oxipng"
 license = "MIT"
 name = "oxipng"
 repository = "https://github.com/oxipng/oxipng"
-version = "10.1.0"
+version = "10.1.1"
 rust-version = "1.85.1"
 
 [badges]
@@ -39,29 +39,28 @@ required-features = ["zopfli"]
 
 [dependencies]
 bitvec = "1.0.1"
-clap = { version = "4.5.53", optional = true, features = ["wrap_help"] }
+clap = { version = "4.6.0", optional = true, features = ["wrap_help"] }
-crossbeam-channel = { version = "0.5.15", optional = true }
+env_logger = { version = "0.11.10", optional = true, default-features = false, features = ["auto-color"] }
-env_logger = { version = "0.11.8", optional = true, default-features = false, features = ["auto-color"] }
 image = { version = "0.25.9", optional = true, default-features = false, features = ["png"] }
-indexmap = "2.13.0"
+indexmap = "2.14.0"
-libdeflater = "1.25.0"
+libdeflater = "1.25.2"
-log = "0.4.29"
+log = "0.4.30"
 parse-size = { version = "1.1.0", optional = true }
 rayon = { version = "1.11.0", optional = true }
-rgb = "0.8.52"
+rgb = "0.8.53"
-rustc-hash = "2.1.1"
+rustc-hash = "2.1.2"
 zopfli = { version = "0.8.3", optional = true, default-features = false, features = ["std", "zlib"] }
 
 [target.'cfg(windows)'.dependencies]
 glob = { version = "0.3.3", optional = true }
 
 [dev-dependencies]
-serde_json = "1.0.147"
+serde_json = "1.0.150"
 
 [features]
 binary = ["dep:clap", "dep:glob", "dep:env_logger", "dep:parse-size"]
 default = ["binary", "parallel", "zopfli"]
-parallel = ["dep:rayon", "indexmap/rayon", "dep:crossbeam-channel"]
+parallel = ["dep:rayon", "indexmap/rayon"]
 freestanding = ["libdeflater/freestanding"]
 sanity-checks = ["dep:image"]
 zopfli = ["dep:zopfli"]

README.md

@@ -8,7 +8,7 @@
 ## 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.
+interface or as a library in other Rust programs. It is fast and highly effective.
 
 ## Installing
 
@@ -76,7 +76,14 @@ 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 without.
+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.
 
 ## Git integration via [pre-commit]
 
@@ -131,17 +138,13 @@ and specifying the desired ones, for example:
 
 ## History
 
-Oxipng began as a complete rewrite of the OptiPNG project,
+Oxipng began in 2015 as a rewrite of the OptiPNG project. The core goal was to implement
-which was assumed to be dead as no commit had been made to it since March 2014.
+multithreading, which would have been very difficult to do within the existing C codebase of OptiPNG.
-(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).
 
-Note that, while similar, Oxipng is not a drop-in replacement for OptiPNG.
+However, Oxipng has evolved considerably since then. While some of the options remain similar to
-If you are migrating from OptiPNG, please check the [help](MANUAL.txt) before using.
+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.
 
 ## Contributing
 
@@ -151,42 +154,11 @@ 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
-
-```

src/cli.rs

@@ -298,6 +298,8 @@ 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),
         )

src/evaluate.rs

@@ -8,12 +8,12 @@ use std::sync::{
     atomic::{AtomicUsize, Ordering::*},
 };
 
-#[cfg(feature = "parallel")]
-use crossbeam_channel::{Receiver, Sender, unbounded};
 use deflate::Deflater;
 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;
@@ -73,7 +73,7 @@ impl Evaluator {
         final_round: bool,
     ) -> Self {
         #[cfg(feature = "parallel")]
-        let eval_channel = unbounded();
+        let eval_channel = channel();
         Self {
             deadline,
             filters,

src/headers.rs

@@ -263,11 +263,11 @@ 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)
     }
-    // The decompressed size is unknown so we have to guess the required buffer size
+    // Libdeflate works with a fixed size buffer. Since the decompressed size is unknown we have to
-    let mut out_size = compressed_data.len() * 2 + 1000;
+    // guess the required buffer size. We allow a fairly generous 10x factor with a minimum of 1000.
-    if let Some(max) = max_size {
+    let mut out_size = (compressed_data.len() * 10).max(1000);
-        out_size = out_size.min(max);
+    // 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) {
         Ok(icc) => Some(icc),
         Err(e) => {

src/main.rs

@@ -430,6 +430,16 @@ fn parse_opts_into_struct(
         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,

src/png/mod.rs

@@ -1,9 +1,7 @@
 use std::{fs, path::Path, sync::Arc};
 
-use bitvec::bitarr;
 use libdeflater::{CompressionLvl, Compressor};
 use log::warn;
-use rgb::ComponentSlice;
 use rustc_hash::FxHashMap;
 
 use crate::{
@@ -192,7 +190,7 @@ 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_slice());
+                    palette_data.extend_from_slice(px.rgb().as_ref());
                 }
                 write_png_block(b"PLTE", &palette_data, &mut output);
                 if let Some(last_trns) = palette.iter().rposition(|px| px.a != 255) {
@@ -374,6 +372,12 @@ impl PngImage {
         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() {
             if prev_pass != line.pass || line.data.len() != prev_line.len() {
                 prev_line = vec![0; line.data.len()];
@@ -465,18 +469,29 @@ impl PngImage {
                         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 set = bitarr![0; 0x10000];
+                            let mut count = 0;
                             for pair in f_buf.windows(2) {
                                 let bigram = ((pair[0] as usize) << 8) | pair[1] as usize;
-                                set.set(bigram, true);
+                                if !bigram_seen[bigram] {
+                                    count += 1;
+                                    if count >= best_size {
+                                        break;
+                                    }
+                                    bigram_seen[bigram] = true;
+                                    bigram_touched.push(bigram as u16);
+                                }
                             }
-                            let size = set.count_ones();
+                            if count < best_size {
-                            if size < best_size {
+                                best_size = count;
-                                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 => {

src/reduction/color.rs

@@ -1,7 +1,7 @@
 use std::hash::{BuildHasherDefault, Hash};
 
 use indexmap::IndexSet;
-use rgb::{ComponentMap, ComponentSlice, FromSlice, RGB, RGBA, alt::Gray};
+use rgb::{ComponentMap, FromSlice, RGB, RGBA, alt::Gray};
 use rustc_hash::FxHasher;
 
 use crate::{
@@ -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_slice()[ch_start..=ch_end]);
+        data.extend_from_slice(&color.as_ref()[ch_start..=ch_end]);
     }
 
     Some(PngImage {

src/reduction/mod.rs

@@ -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 && !deadline.passed() {
+    if opts.color_type_reduction && opts.palette_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));

tests/flags.rs

@@ -1,13 +1,12 @@
+use indexmap::indexset;
+use oxipng::{internal_tests::*, *};
+use serde_json::Value;
 use std::{
     fs::remove_file,
     path::{Path, PathBuf},
     process::Command,
 };
 
-use indexmap::indexset;
-use oxipng::{internal_tests::*, *};
-use serde_json::Value;
-
 const GRAY: u8 = 0;
 const RGB: u8 = 2;
 const INDEXED: u8 = 3;
@@ -97,13 +96,9 @@ fn test_it_converts(
 
 #[test]
 fn verbose_mode() {
-    use std::cell::RefCell;
-    #[cfg(not(feature = "parallel"))]
-    use std::sync::mpsc::{Sender, channel as unbounded};
-
-    #[cfg(feature = "parallel")]
-    use crossbeam_channel::{Sender, unbounded};
     use log::{Level, LevelFilter, Log, Metadata, Record, set_logger, set_max_level};
+    use std::cell::RefCell;
+    use std::sync::mpsc::{Sender, channel};
 
     // Rust runs tests in parallel by default.
     // We want to make sure that we verify only logs from our test.
@@ -143,7 +138,7 @@ fn verbose_mode() {
     let input = PathBuf::from("tests/files/verbose_mode.png");
     let (output, opts) = get_opts(&input);
 
-    let (sender, receiver) = unbounded();
+    let (sender, receiver) = channel();
 
     let thread_init = move || {
         // Initialise logs storage for all threads within our test.