colorjs.io/src/spaces/rec2020.js

Color space agnostic color manipulation library

import Color, {util} from "./srgb.js";

Color.defineSpace({
	inherits: "srgb",
	id: "rec2020",
	name: "REC.2020",
	α: 1.09929682680944,
	β: 0.018053968510807,
	toLinear(RGB) {
		const {α, β} = this;

		return RGB.map(function (val) {
			if (val < β * 4.5 ) {
				return val / 4.5;
			}

			return Math.pow((val + α -1 ) / α, 2.4);
		});
	},
	toGamma(RGB) {
		const {α, β} = this;

		return RGB.map(function (val) {
			if (val > β ) {
				return α * Math.pow(val, 1/2.4) - (α - 1);
			}

			return 4.5 * val;
		});
	},
	// convert an array of linear-light rec2020 values to CIE XYZ
	// using  D65 (no chromatic adaptation)
	// http://www.brucelindbloom.com/index.html?Eqn_RGB_XYZ_Matrix.html
	// 0 is actually calculated as  4.994106574466076e-17
	toXYZ_M: [
		[ 0.6369580483012914, 0.14461690358620832,  0.1688809751641721  ],
		[ 0.2627002120112671, 0.6779980715188708,   0.05930171646986196 ],
		[ 0.000000000000000,  0.028072693049087428, 1.060985057710791   ]
	],
	// from ITU-R BT.2124-0 Annex 2 p.3
	fromXYZ_M: [
		[  1.716651187971268,  -0.355670783776392, -0.253366281373660  ],
		[ -0.666684351832489,   1.616481236634939,  0.0157685458139111 ],
		[  0.017639857445311,  -0.042770613257809,  0.942103121235474  ]
	]
});

export default Color;
export {util};