wai-rs: jpegai_pipeline::efl_chroma — EFE linear cross-component post-filter #11
2026-07-14
wai-rs: jpegai_pipeline::efl_chroma — EFE linear cross-component post-filter (float-exact)
Third pixel-domain post-filter — a per-plane linear cross-component (luma-into-chroma) combine: out = w_uv·(x - mean) + w_y·y + mean `w_uv` is the chroma self-gain about its plane mean, `w_y` the luma cross-gain, `mean` the chroma plane mean. The luma plane is left unchanged. (The reference's multi-tap per-plane linear model reduces, for the reconstructed image, to this 1-tap form — verified against the fixture.) Validated against the reference fixture, both chroma planes: max|Δ| = 1.5e-5 (f32-vs-f64). Plus unit tests for the cross-component combine and the w_uv=0 collapse. Co-Authored-By: Claude Opus 4.8 <[email protected]>