Soft proof — jsColorEngine vs lcms-wasm
Same image, same ICC profile, same sRGB → CMYK conversion and same sRGB → CMYK → sRGB soft-proof pipeline, two engines side-by-side. The centre panel shows the pixel-by-pixel difference with an amplification slider (up to 128×). Three conclusions in ~15 seconds: accuracy (visually identical), speed (inline timing), and simplicity (JS-only vs +340 KB WASM).
jsCE uses ICCImage.toProof() ·
lcms-wasm uses cmsCreateTransform +
cmsDoTransform ·
Max diffs are typically at the gamut boundary where each CMS
clips/compresses slightly differently — use the gain slider
and hover picker to compare.
jsColorEngine
Pixel diff
use slider to amplify invisible differences
lcms-wasm
Accuracy stats
Max CMYK diff—
Mean CMYK diff—
Max RGB diff—
Mean RGB diff—
Exact match—
≤ 1 LSB—
≤ 2 LSB—
jsCE time—
lcms time—
Speed ratio—