Use a supplied RGB ICC profile

Enable the optional parser when your application already has profile bytes. The parser supplies validated colorants and curves to the f64 color core. It does not decode image files, select a monitor profile or run a general ICC transform engine.

[dependencies]
xgpui-color = { path = "../../extensions/crates/xgpui-color", features = ["icc"] }

Parse once, then attach the definition to pixels

use std::sync::Arc;
use xgpui_color::icc::IccRgbProfile;
use xgpui_media::pipeline::{AlphaMode, PixelColor};

fn interpretation(profile_bytes: &[u8]) -> anyhow::Result<PixelColor> {
    let profile = IccRgbProfile::parse(profile_bytes)?;
    Ok(PixelColor::Custom {
        rgb: Arc::new(profile.into_rgb_definition()),
        alpha: AlphaMode::Straight,
    })
}

Pass that interpretation to MediaLoader::load_pixel_buffer with the decoded RGBA samples, an explicit storage space and mapping policy. Reuse the immutable definition across pixels; parse outside rendering and keep admission of profile bytes/work on the application's bounded workers. Source alpha remains with the caller. Pixels and metadata covers the full flow.

Supported subset

Limits include 512 KiB/profile, 32 tags, 65,536 samples/curve and 4 KiB per admitted informational tag. Exact shared tag ranges are allowed; partial overlap is rejected. Large parametric coefficients outside the parser's exact admitted range are rejected. The adapter rejects CICP combinations and unsupported transform tags instead of guessing precedence.

LUT profiles, CMYK, gray, HDR/iccMAX, arbitrary rendering-intent transforms, black-point compensation and display calibration are outside this subset. Informational luminance, measurement, black-point, technology and viewing-text tags do not add those operations to the relative matrix/TRC decode.

Why sRGB2014 is not replaced with named sRGB

A profile's name is not a conversion rule. The pinned sRGB2014 fixture contains a 1024-entry curve and a small encoded neutral-axis offset. Both are retained. RgbDefinition::from_relative_xyz_matrix separates the declared XYZ reference white from the actual transform's matrix sum. The neutral-space constructors remain available for definitions that must map neutral RGB onto their declared white. No column normalization or wider conversion tolerance is used to admit the profile.

Tested profiles and boundaries

The pinned published corpus accepts Compact v4 sRGB, Display P3, Adobe-compatible RGB, and the ICC-authored sRGB2014 mirror. Compact v2 fixtures with overlapping packed tag ranges are intentionally rejected; this describes our admission policy, not a claim that the upstream files are corrupt. Grayscale and CMYK fixtures are also explicit rejections.

There are 4,108 independent 120-digit exact-tag vectors for the accepted published profiles, plus synthetic curve and adaptation tests. They cover near-black, mixed colors, endpoints, threshold neighbors and sampled knots. The f64 source-energy precision budgets are separate from FP16 storage budgets. A secondary Little CMS endpoint check confirms the retained relative PCS matrix; its interpolation behavior does not define the core's sampled-curve contract.

Try identical pixels with different metadata in Wasm, or inspect them in the native lab. Provenance, licenses, hashes and detailed results live with the profile fixtures. Historical engine evaluations are retained in validation notes.