oxipng/src/sanity_checks.rs
andrews05 5a66e77581
Update dependencies and bump MSRV (#606)
Updates all dependencies to latest versions and bumps MSRV to 1.74 (to
match clap).
Some changes required for `env_logger` and `image`.
2024-04-13 14:58:19 +02:00

61 lines
2.1 KiB
Rust

use image::{codecs::png::PngDecoder, *};
use log::{error, warn};
use std::io::Cursor;
/// Validate that the output png data still matches the original image
pub fn validate_output(output: &[u8], original_data: &[u8]) -> bool {
let (old_frames, new_frames) = rayon::join(
|| load_png_image_from_memory(original_data),
|| load_png_image_from_memory(output),
);
match (new_frames, old_frames) {
(Err(new_err), _) => {
error!("Failed to read output image for validation: {}", new_err);
false
}
(_, Err(old_err)) => {
// The original image might be invalid if, for example, there is a CRC error,
// and we set fix_errors to true. In that case, all we can do is check that the
// new image is decodable.
warn!("Failed to read input image for validation: {}", old_err);
true
}
(Ok(new_frames), Ok(old_frames)) if new_frames.len() != old_frames.len() => false,
(Ok(new_frames), Ok(old_frames)) => {
for (a, b) in old_frames.iter().zip(new_frames) {
if !images_equal(a, &b) {
return false;
}
}
true
}
}
}
/// Loads a PNG image from memory to frames of [RgbaImage]
fn load_png_image_from_memory(png_data: &[u8]) -> Result<Vec<RgbaImage>, image::ImageError> {
let decoder = PngDecoder::new(Cursor::new(png_data))?;
if decoder.is_apng()? {
decoder
.apng()?
.into_frames()
.map(|f| f.map(|f| f.into_buffer()))
.collect()
} else {
DynamicImage::from_decoder(decoder).map(|i| vec![i.into_rgba8()])
}
}
/// Compares images pixel by pixel for equivalent content
fn images_equal(old_png: &RgbaImage, new_png: &RgbaImage) -> bool {
let a = old_png.pixels().filter(|x| {
let p = x.channels();
!(p.len() == 4 && p[3] == 0)
});
let b = new_png.pixels().filter(|x| {
let p = x.channels();
!(p.len() == 4 && p[3] == 0)
});
a.eq(b)
}