Editor › Features › ICC Colour Management in the Browser
Can a browser image editor do real ICC colour management?
PhotoAIA runs LittleCMS (lcms) in WebAssembly, so it performs genuine ICC transforms: profile-driven RGB to CMYK separation, all four rendering intents, black point compensation, and soft proofing with media simulation.
What is managed
- Separation profile — drives RGB to CMYK conversion and the plate values.
- Soft-proof profile — previews the document as the chosen output condition will render it, without changing pixels.
- Rendering intent — perceptual, relative colorimetric, saturation, absolute colorimetric.
- Black point compensation — toggled independently for conversion and proofing.
Where the profile ends up
When you export a TIFF, the profile bytes are embedded in the file. When you export a PSD, an RGB profile is written verbatim as PSD image resource 1039 — a CMYK profile is deliberately withheld, because PSD export writes RGB pixels and tagging them as CMYK would mislabel the file.
Limitations worth knowing
- Soft proofing is a preview. It never alters stored pixels.
- Built-in sRGB has no binary payload, so a document using it exports untagged rather than with a fabricated profile.
- PDF output embeds the profile as an OutputIntent but is not certified PDF/X — see the PDF page.