color-thief/dist/color-thief.js

/**
 * 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<ndarray.NdArray<Uint8Array>>} 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<ColorThiefResult>} 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<ColorThiefResult[]>} 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,
};