chroma-js/src/utils/distance.js

JavaScript library for color conversions

const Color = require('../Color');

// simple Euclidean distance
module.exports = function(a, b, mode='lab') {
    // Delta E (CIE 1976)
    // see http://www.brucelindbloom.com/index.html?Equations.html
    a = new Color(a);
    b = new Color(b);
    const l1 = a.get(mode);
    const l2 = b.get(mode);
    let sum_sq = 0;
    for (let i in l1) {
        const d = (l1[i] || 0) - (l2[i] || 0);
        sum_sq += d*d;
    }
    return Math.sqrt(sum_sq);
};