/** * Color Thief Node v3.0.0 * by Lokesh Dhakar - http://www.lokeshdhakar.com * * Thanks * ------ * Nick Rabinowitz - For creating quantize.js. * John Schulz - For clean up and optimization. @JFSIII * Nathan Spady - For adding drag and drop support to the demo page. * * License * ------- * Copyright Lokesh Dhakar * Released under the MIT license * https://raw.githubusercontent.com/lokesh/color-thief/master/LICENSE * * @license MIT */ // Thanks to this PR for the work of migrating to ndarray-pixels pr https://github.com/lokesh/color-thief/pull/254 import { getPixels } from 'ndarray-pixels'; import quantize from '@lokesh.dhakar/quantize'; import sharp from 'sharp'; /** * Create an array of arrays of pixels from an array of pixels * @param {number[]} pixels An array of pixels * @param {number} pixelCount The total number of pixels * @param {number} quality * @returns {number[][]} Returns an array of arrays of pixel values ([ r, g, b ]) */ const createPixelArray = (pixels, pixelCount, quality) => { const pixelArray = []; for (let i = 0; i < pixelCount; i = i + quality) { const offset = i * 4; const r = pixels[offset + 0]; const g = pixels[offset + 1]; const b = pixels[offset + 2]; const a = pixels[offset + 3]; // If pixel is mostly opaque and not white if (typeof a === 'undefined' || a >= 125) { if (!(r > 250 && g > 250 && b > 250)) { pixelArray.push([r, g, b]); } } } return pixelArray; }; /** * Validate Color-Thief options * @param {{ colorCount: number; quality: number; }} options The options object * @returns {{ colorCount: number, quality: number }} The same object, but validated */ const validateOptions = (options) => { let colorCount = options.colorCount; let quality = options.quality; if (typeof colorCount === 'undefined' || !Number.isInteger(colorCount)) { colorCount = 10; } else if (colorCount === 1) { throw new Error('colorCount should be between 2 and 20. To get one color, call getColor() instead of getPalette()'); } else { colorCount = Math.max(colorCount, 2); colorCount = Math.min(colorCount, 20); } if (typeof quality === 'undefined' || !Number.isInteger(quality) || quality < 1) { quality = 10; } return { colorCount, quality, }; }; /** * Load an image from the disk an pre-process * @param {string} img Path to the image on the disk * @returns {Promise>} Returns the pre-processed image */ const loadImg = (img) => { return new Promise((resolve, reject) => { sharp(img) .toBuffer() .then((buffer) => sharp(buffer).metadata() .then((metadata) => ({ buffer, 'format': metadata.format }))) .then(({ buffer, format }) => getPixels(buffer, format)) .then(resolve) .catch(reject); }); }; /** * Get the dominant color of an image * @param {string} img Path to the image on the disk * @param {number?} quality (Optional) 1 = highest quality, 10 = default. The bigger the number, the * faster a color will be returned but the greater the likelihood that it will not be the visually * most dominant color. * @returns {Promise} Returns the dominant color */ const getColor = (img, quality = 10) => { return new Promise((resolve, reject) => { getPalette(img, 5, quality) .then((palette) => { resolve(palette[0]); }) .catch((err) => { reject(err); }); }); }; /** * Get the color palette of an image * @param {string} img Path to the image on the disk * @param {number?} colorCount (Optional) the target amount of colors to try and extract * @param {number?} quality (Optional) 1 = highest quality, 10 = default. The bigger the number, the * faster a color will be returned but the greater the likelihood that it will not be the visually * most dominant color. * @returns {Promise} Returns an array of colors */ const getPalette = (img, colorCount = 10, quality = 10) => { const options = validateOptions({ colorCount, quality, }); return new Promise((resolve, reject) => { loadImg(img) .then((imgData) => { const pixelCount = imgData.shape[0] * imgData.shape[1]; const pixelArray = createPixelArray(Array.from(imgData.data), pixelCount, options.quality); const cmap = quantize(pixelArray, options.colorCount); const palette = cmap ? cmap.palette() : null; resolve(palette); }) .catch((err) => { reject(err); }); }); }; module.exports = { getColor, getPalette, };