first

plugins/color-thief/2.3.0/color-thief.js

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+const getPixels = require('get-pixels');
+const quantize = require('quantize');
+
+function createPixelArray(imgData, pixelCount, quality) {
+    const pixels = imgData;
+    const pixelArray = [];
+
+    for (let i = 0, offset, r, g, b, a; i < pixelCount; i = i + quality) {
+        offset = i * 4;
+        r = pixels[offset + 0];
+        g = pixels[offset + 1];
+        b = pixels[offset + 2];
+        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;
+}
+
+function validateOptions(options) {
+    let { colorCount, quality } = options;
+
+    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 = 10;
+    } else if (quality < 1) {
+        quality = 10;
+    }
+
+    return {
+        colorCount,
+        quality
+    }
+}
+
+function loadImg(img) {
+    return new Promise((resolve, reject) => {
+        getPixels(img, function(err, data) {
+            if(err) {
+                reject(err)
+            } else {
+                resolve(data);
+            }
+        })
+    });
+}
+
+function getColor(img, quality) {
+    return new Promise((resolve, reject) => {
+        getPalette(img, 5, quality)
+            .then(palette => {
+                resolve(palette[0]);
+            })
+            .catch(err => {
+                reject(err);
+            })
+    });
+
+}
+
+function 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(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
+};
+