64 lines
1.7 KiB
Rust
64 lines
1.7 KiB
Rust
// Regression tests for dithering methods. This file ensures that changes made to how the
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// algorithms are implemented does not affect the actual algorithm. This is done with
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// 'known-good' sample images (see `samples/`). If changes to the algorithms are made,
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// these tests will fail, and that is to be expected. In that case the reference images
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// will need to be updated as well.
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use anyhow::Result;
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use image::{ImageReader, RgbImage};
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use pi_frame_server::dither::{DitherMethod, DitheredImage, Palette};
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fn compare_original(sample_file: &str, reference_file: &str, method: &DitherMethod) -> Result<()> {
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let image: RgbImage = ImageReader::open(format!("samples/{sample_file}"))?
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.decode()?
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.into_rgb8();
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// process
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let mut method = method.get_ditherer();
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let mut result = DitheredImage::new(
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image.width(),
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image.height(),
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Palette::Default.value().to_vec(),
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);
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method.dither(&image, &mut result);
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let expected = ImageReader::open(format!("tests/known_samples/{reference_file}"))?
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.decode()?
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.into_rgb8()
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.into_raw();
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let output = result.into_rgbimage().into_raw();
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assert_eq!(output, expected);
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Ok(())
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}
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#[test]
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fn sample_0_atkinson() -> Result<()> {
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compare_original(
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"sample_0.tiff",
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"sample_0_atkinson.tiff",
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&DitherMethod::Atkinson,
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)
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}
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#[test]
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fn sample_1_atkinson() -> Result<()> {
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compare_original(
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"sample_1.tiff",
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"sample_1_atkinson.tiff",
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&DitherMethod::Atkinson,
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)
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}
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#[test]
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fn sample_1_floydsteinberg() -> Result<()> {
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compare_original(
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"sample_1.tiff",
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"sample_1_floydsteinberg.tiff",
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&DitherMethod::FloydSteinberg,
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)
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}
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