Search for an artist to see generated color palettes for all the album
art in their discog.
{loading && (
)}
{!loading && renderedAlbums}
);
}
}
export default App;
================================================
FILE: demo/src/index.js
================================================
import React from "react";
import ReactDOM from "react-dom";
import App from "./App";
ReactDOM.render(, document.getElementById("root"));
================================================
FILE: demo/src/main.css
================================================
.container {
font-family: 'Nunito', sans-serif;
text-align: center;
padding: 5px;
}
.title {
font-size: 20px;
margin-bottom: 0px;
}
.search--container {
display: flex;
justify-content: center;
margin-bottom: 20px;
max-width: 362px;
margin: 10px auto;
}
.search--input {
box-sizing: border-box;
height: 40px;
font-size: 16px;
padding: 10px;
border: 1px solid #efefef;
outline: none;
width: 100%;
}
.search--button {
background-color: #37474f;
color: #ffffff;
font-size: 14px;
border: none;
width: 20%;
}
.album--container {
display: flex;
flex-wrap: wrap;
justify-content: center;
}
.album {
box-sizing: border-box;
width: 100%;
max-width: 400px;
padding: 30px;
margin: 10px 0px;
display: flex;
flex-direction: column;
align-items: center;
}
.album img {
width: 280px;
}
.spinner--container {
display: flex;
align-items: center;
height: 200px;
}
.github-ribbon {
display: none;
}
@media screen and (min-width: 350px) {
.title {
font-size: 25px;
}
}
@media screen and (min-width: 768px) {
.title {
font-size: 35px;
}
.album {
width: 400px;
margin: 20px;
}
.album img {
width: 300px;
}
.github-ribbon {
display: block;
}
}
@media screen and (min-width: 1024px) {
.title {
font-size: 40px;
}
}
================================================
FILE: karma.conf.js
================================================
module.exports = config => {
config.set({
// client: {
// mocha: {
// timeout: 6000
// }
// },
frameworks: ['mocha', 'chai'],
files: ['./packages/**/__tests__/**/*.js'],
preprocessors: {
'./packages/**/__tests__/**/*.js': ['webpack']
},
webpack: {
module: {
loaders: [
{
test: /\.png$/,
loader: 'url-loader'
}
]
}
},
webpackMiddleware: {
quiet: true
},
reporters: ['mocha'],
port: 9876,
colors: true,
logLevel: config.LOG_INFO,
browsers: ['ChromeHeadless'],
autoWatch: false,
concurrency: Infinity
});
};
================================================
FILE: lerna.json
================================================
{
"lerna": "2.1.2",
"packages": [
"packages/*"
],
"version": "independent"
}
================================================
FILE: package.json
================================================
{
"name": "image-palette",
"private": true,
"scripts": {
"test": "lerna run test",
"build": "lerna run build"
},
"devDependencies": {
"babel-cli": "^6.26.0",
"babel-preset-env": "^1.6.0",
"babel-preset-react": "^6.24.1",
"chai": "^4.1.2",
"flow-bin": "^0.55.0",
"karma": "^1.7.1",
"karma-chai": "^0.1.0",
"karma-chrome-launcher": "^2.2.0",
"karma-mocha": "^1.3.0",
"karma-mocha-reporter": "^2.2.4",
"karma-webpack": "^2.0.4",
"lerna": "^2.1.2",
"mocha": "^3.5.3",
"prettier": "^1.7.2",
"rimraf": "^2.6.2",
"url-loader": "^0.6.2",
"webpack": "^3.8.1"
}
}
================================================
FILE: packages/image-palette-core/.npmignore
================================================
/*
!/lib
!/es
!/src
!LICENSE.txt
!README.md
!package.json
================================================
FILE: packages/image-palette-core/README.md
================================================
# image-palette-core
The core logic for parsing a palette from image data. You can use this if you want an imperative
API for generating a palette. If you want to use it with React you can use [`react-image-palette`](https://github.com/FormidableLabs/image-palette/tree/master/packages/react-image-palette)
### Install
```
npm install --save image-palette-core
```
## Usage
The main export of the package is a `getImagePalette` function which takes an image and returns an accessible color palette representing the most dominant colors in the image.
```js
import getImagePalette from 'image-palette-core'
const img = new Image();
img.src = 'foo.jpg';
img.onload = function() {
// The image *must* be loaded before calling `getImagePalette`
const palette = getImagePalette(img);
}
```
> ⚠️ Keep in mind that the image will be loaded into a canvas and parsed as data, so you should only use images from trusted origins.
### The Palette
The parsed palette will have the following shape:
```
type Palette = {
backgroundColor: String,
color: String,
alternativeColor: String
}
```
* `backgroundColor` will be the most dominant color in the image.
* `color` will be the color that looks the best overlayed over `backgroundColor`.
* `alternativeColor` will be the second best color. If there are only two colors parsed, it will default to `color`.
Both `alternativeColor` and `color` are guaranteed to meet the minimum contrast ratio requirements when overlayed with `backgroundColor`, but overlaying `color` on `alternativeColor` (or vice-versa) is a bad idea as they will often have very similar contrast levels.
================================================
FILE: packages/image-palette-core/__tests__/test.js
================================================
import getImagePalette from "../lib";
// Album cover for Com Truise - Fairlight
import testImage from "./fairlight.png";
describe("image-palette-core", () => {
describe("provider", () => {
it("should parse a palette from an image", done => {
const img = new Image();
img.src = testImage;
img.onload = () => {
const palette = getImagePalette(img);
expect(palette.backgroundColor).to.equal("rgb(60, 16, 32)");
expect(palette.color).to.equal("#EF4E2E");
expect(palette.alternativeColor).to.equal("#D17872");
done();
};
});
});
});
================================================
FILE: packages/image-palette-core/package.json
================================================
{
"name": "image-palette-core",
"version": "0.2.2",
"description": "Create ARIA-compliant color themes based on any image.",
"main": "lib/index.js",
"module": "es/index.js",
"jsnext:main": "es/index.js",
"author": "Brandon Dail",
"license": "MIT",
"scripts": {
"build": "npm run clean && npm run build:es && npm run build:lib",
"build:es": "BABEL_ENV=es babel src --out-dir es",
"build:lib": "BABEL_ENV=commonjs babel src --out-dir lib",
"clean": "rimraf es lib",
"preversion": "npm run test",
"test:only": "karma start --single-run --browsers ChromeHeadless ../../karma.conf.js",
"test": "npm run build && npm run test:only"
},
"dependencies": {
"color": "^2.0.0",
"lodash.isequal": "^4.5.0",
"lodash.sortby": "^4.7.0",
"lodash.uniq": "^4.5.0",
"lodash.uniqby": "^4.7.0"
}
}
================================================
FILE: packages/image-palette-core/src/color-thief.js
================================================
/*
* Color Thief v2.0
* by Lokesh Dhakar - http://www.lokeshdhakar.com
*
* License
* -------
* Creative Commons Attribution 2.5 License:
* http://creativecommons.org/licenses/by/2.5/
*
* 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.
*
*/
/*
CanvasImage Class
Class that wraps the html image element and canvas.
It also simplifies some of the canvas context manipulation
with a set of helper functions.
*/
var iAmOnNode = false;
var Canvas;
var Image;
var fs;
if ( !!process && process.execPath ) {
iAmOnNode = true;
}
// if (iAmOnNode) {
// Canvas = require('canvas');
// Image = Canvas.Image;
// fs = require('fs');
// }
var vboxColorMap = {};
var CanvasImage = function (image) {
// in node we use strings as path to an image
// whereas in the browser we use an image element
if (iAmOnNode) {
this.canvas = new Canvas()
var img = new Image;
if(image instanceof Buffer) {
img.src = image
}else{
img.src = fs.readFileSync(image);
}
} else {
this.canvas = document.createElement('canvas');
document.body.appendChild(this.canvas);
var img = image;
}
this.context = this.canvas.getContext('2d');
this.width = this.canvas.width = img.width;
this.height = this.canvas.height = img.height;
this.context.drawImage(img, 0, 0, this.width, this.height);
};
CanvasImage.prototype.clear = function () {
this.context.clearRect(0, 0, this.width, this.height);
};
CanvasImage.prototype.update = function (imageData) {
this.context.putImageData(imageData, 0, 0);
};
CanvasImage.prototype.getPixelCount = function () {
return this.width * this.height;
};
CanvasImage.prototype.getImageData = function () {
return this.context.getImageData(0, 0, this.width, this.height);
};
CanvasImage.prototype.removeCanvas = function () {
if (this.canvas.parentNode) {
this.canvas.parentNode.removeChild(this.canvas);
}
};
var ColorThief = function () {};
/*
* getColor(sourceImage[, quality])
* returns {r: num, g: num, b: num}
*
* Use the median cut algorithm provided by quantize.js to cluster similar
* colors and return the base color from the largest cluster.
*
* Quality is an optional argument. It needs to be an integer. 0 is the highest quality settings.
* 10 is the default. There is a trade-off between quality and speed. 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.
*
* */
ColorThief.prototype.getColor = function(sourceImage, quality, allowWhite) {
// control if second parameter is allowWhite
if (quality === true || quality === false) {
allowWhite = quality;
quality = undefined;
}
var palette = this.getPalette(sourceImage, 5, quality, allowWhite);
var dominantColor = palette[0];
return dominantColor;
};
/*
* getPalette(sourceImage[, colorCount, quality])
* returns array[ {r: num, g: num, b: num}, {r: num, g: num, b: num}, ...]
*
* Use the median cut algorithm provided by quantize.js to cluster similar colors.
*
* colorCount determines the size of the palette; the number of colors returned. If not set, it
* defaults to 10.
*
* BUGGY: Function does not always return the requested amount of colors. It can be +/- 2.
*
* quality is an optional argument. It needs to be an integer. 0 is the highest quality settings.
* 10 is the default. There is a trade-off between quality and speed. The bigger the number, the
* faster the palette generation but the greater the likelihood that colors will be missed.
*
*
*/
ColorThief.prototype.getPalette = function(sourceImage, colorCount, quality, allowWhite) {
if (typeof colorCount === 'undefined') {
colorCount = 10;
};
if (typeof quality === 'undefined') {
quality = 10;
};
// Create custom CanvasImage object
var image = new CanvasImage(sourceImage);
var imageData = image.getImageData();
var pixels = imageData.data;
var pixelCount = image.getPixelCount();
var palette = this.getPaletteFromPixels(pixels, pixelCount, colorCount, quality, allowWhite);
// Clean up
image.removeCanvas();
return palette;
};
/*
* getPaletteFromPixels(pixels, pixelCount, colorCount, quality)
* returns array[ {r: num, g: num, b: num}, {r: num, g: num, b: num}, ...]
*
* Low-level function that takes pixels and computes color palette.
* Used by getPalette() and getColor()
*
*/
ColorThief.prototype.getPaletteFromPixels = function(pixels, pixelCount, colorCount, quality) {
var allowWhite = true;
// Store the RGB values in an array format suitable for quantize function
var pixelArray = [];
for (var 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 (a >= 125) {
if (!(r > 255 && g > 255 && b > 255)) {
pixelArray.push([r, g, b]);
}
}
}
// Send array to quantize function which clusters values
// using median cut algorithm
var cmap = MMCQ.quantize(pixelArray, colorCount);
var palette = cmap.palette();
return palette;
}
/*!
* quantize.js Copyright 2008 Nick Rabinowitz.
* Licensed under the MIT license: http://www.opensource.org/licenses/mit-license.php
*/
// fill out a couple protovis dependencies
/*!
* Block below copied from Protovis: http://mbostock.github.com/protovis/
* Copyright 2010 Stanford Visualization Group
* Licensed under the BSD License: http://www.opensource.org/licenses/bsd-license.php
*/
if (!pv) {
var pv = {
map: function(array, f) {
var o = {};
return f
? array.map(function(d, i) { o.index = i; return f.call(o, d); })
: array.slice();
},
naturalOrder: function(a, b) {
return (a < b) ? -1 : ((a > b) ? 1 : 0);
},
sum: function(array, f) {
var o = {};
return array.reduce(f
? function(p, d, i) { o.index = i; return p + f.call(o, d); }
: function(p, d) { return p + d; }, 0);
},
max: function(array, f) {
return Math.max.apply(null, f ? pv.map(array, f) : array);
}
};
}
/**
* Basic Javascript port of the MMCQ (modified median cut quantization)
* algorithm from the Leptonica library (http://www.leptonica.com/).
* Returns a color map you can use to map original pixels to the reduced
* palette. Still a work in progress.
*
* @author Nick Rabinowitz
* @example
// array of pixels as [R,G,B] arrays
var myPixels = [[190,197,190], [202,204,200], [207,214,210], [211,214,211], [205,207,207]
// etc
];
var maxColors = 4;
var cmap = MMCQ.quantize(myPixels, maxColors);
var newPalette = cmap.palette();
var newPixels = myPixels.map(function(p) {
return cmap.map(p);
});
*/
var MMCQ = (function() {
// private constants
var sigbits = 5,
rshift = 8 - sigbits,
maxIterations = 1000,
fractByPopulations = 0.75;
// get reduced-space color index for a pixel
function getColorIndex(r, g, b) {
return (r << (2 * sigbits)) + (g << sigbits) + b;
}
// Simple priority queue
function PQueue(comparator) {
var contents = [],
sorted = false;
function sort() {
contents.sort(comparator);
sorted = true;
}
return {
push: function(o) {
contents.push(o);
sorted = false;
},
peek: function(index) {
if (!sorted) sort();
if (index===undefined) index = contents.length - 1;
return contents[index];
},
pop: function() {
if (!sorted) sort();
return contents.pop();
},
size: function() {
return contents.length;
},
map: function(f) {
return contents.map(f);
},
debug: function() {
if (!sorted) sort();
return contents;
}
};
}
// 3d color space box
function VBox(r1, r2, g1, g2, b1, b2, histo) {
var vbox = this;
vbox.r1 = r1;
vbox.r2 = r2;
vbox.g1 = g1;
vbox.g2 = g2;
vbox.b1 = b1;
vbox.b2 = b2;
vbox.histo = histo;
}
VBox.prototype = {
volume: function(force) {
var vbox = this;
if (!vbox._volume || force) {
vbox._volume = ((vbox.r2 - vbox.r1 + 1) * (vbox.g2 - vbox.g1 + 1) * (vbox.b2 - vbox.b1 + 1));
}
return vbox._volume;
},
count: function(force) {
var vbox = this,
histo = vbox.histo;
if (!vbox._count_set || force) {
var npix = 0,
i, j, k;
for (i = vbox.r1; i <= vbox.r2; i++) {
for (j = vbox.g1; j <= vbox.g2; j++) {
for (k = vbox.b1; k <= vbox.b2; k++) {
var index = getColorIndex(i,j,k);
npix += (histo[index] || 0);
}
}
}
vbox._count = npix;
vbox._count_set = true;
}
return vbox._count;
},
copy: function() {
var vbox = this;
return new VBox(vbox.r1, vbox.r2, vbox.g1, vbox.g2, vbox.b1, vbox.b2, vbox.histo);
},
avg: function(force) {
var vbox = this,
histo = vbox.histo;
if (!vbox._avg || force) {
var ntot = 0,
mult = 1 << (8 - sigbits),
rsum = 0,
gsum = 0,
bsum = 0,
hval,
i, j, k, histoindex;
for (i = vbox.r1; i <= vbox.r2; i++) {
for (j = vbox.g1; j <= vbox.g2; j++) {
for (k = vbox.b1; k <= vbox.b2; k++) {
histoindex = getColorIndex(i,j,k);
hval = histo[histoindex] || 0;
ntot += hval;
rsum += (hval * (i + 0.5) * mult);
gsum += (hval * (j + 0.5) * mult);
bsum += (hval * (k + 0.5) * mult);
}
}
}
if (ntot) {
vbox._avg = [~~(rsum/ntot), ~~(gsum/ntot), ~~(bsum/ntot)];
} else {
vbox._avg = [
~~(mult * (vbox.r1 + vbox.r2 + 1) / 2),
~~(mult * (vbox.g1 + vbox.g2 + 1) / 2),
~~(mult * (vbox.b1 + vbox.b2 + 1) / 2)
];
}
}
return vbox._avg;
},
contains: function(pixel) {
var vbox = this,
rval = pixel[0] >> rshift;
gval = pixel[1] >> rshift;
bval = pixel[2] >> rshift;
return (rval >= vbox.r1 && rval <= vbox.r2 &&
gval >= vbox.g1 && gval <= vbox.g2 &&
bval >= vbox.b1 && bval <= vbox.b2);
}
};
// Color map
function CMap() {
this.vboxes = new PQueue(function(a,b) {
return pv.naturalOrder(
a.vbox.count()*a.vbox.volume(),
b.vbox.count()*b.vbox.volume()
)
});;
}
CMap.prototype = {
push: function(vbox) {
this.vboxes.push({
vbox: vbox,
rgb: vbox.avg(),
count: vbox.count()
});
},
palette: function() {
return this.vboxes.map(function(vb) { return { rgb: vb.rgb, count: vb.count } });
},
size: function() {
return this.vboxes.size();
},
map: function(color) {
var vboxes = this.vboxes;
for (var i=0; i 251
var idx = vboxes.length-1,
highest = vboxes[idx].color;
if (highest[0] > 251 && highest[1] > 251 && highest[2] > 251)
vboxes[idx].color = [255,255,255];
}
};
// histo (1-d array, giving the number of pixels in
// each quantized region of color space), or null on error
function getHisto(pixels) {
var histosize = 1 << (3 * sigbits),
histo = new Array(histosize),
index, rval, gval, bval;
pixels.forEach(function(pixel) {
rval = pixel[0] >> rshift;
gval = pixel[1] >> rshift;
bval = pixel[2] >> rshift;
index = getColorIndex(rval, gval, bval);
histo[index] = (histo[index] || 0) + 1;
});
return histo;
}
function vboxFromPixels(pixels, histo) {
var rmin=1000000, rmax=0,
gmin=1000000, gmax=0,
bmin=1000000, bmax=0,
rval, gval, bval;
// find min/max
pixels.forEach(function(pixel) {
rval = pixel[0] >> rshift;
gval = pixel[1] >> rshift;
bval = pixel[2] >> rshift;
if (rval < rmin) rmin = rval;
else if (rval > rmax) rmax = rval;
if (gval < gmin) gmin = gval;
else if (gval > gmax) gmax = gval;
if (bval < bmin) bmin = bval;
else if (bval > bmax) bmax = bval;
});
return new VBox(rmin, rmax, gmin, gmax, bmin, bmax, histo);
}
function medianCutApply(histo, vbox) {
if (!vbox.count()) return;
var rw = vbox.r2 - vbox.r1 + 1,
gw = vbox.g2 - vbox.g1 + 1,
bw = vbox.b2 - vbox.b1 + 1,
maxw = pv.max([rw, gw, bw]);
// only one pixel, no split
if (vbox.count() == 1) {
return [vbox.copy()]
}
/* Find the partial sum arrays along the selected axis. */
var total = 0,
partialsum = [],
lookaheadsum = [],
i, j, k, sum, index;
if (maxw == rw) {
for (i = vbox.r1; i <= vbox.r2; i++) {
sum = 0;
for (j = vbox.g1; j <= vbox.g2; j++) {
for (k = vbox.b1; k <= vbox.b2; k++) {
index = getColorIndex(i,j,k);
sum += (histo[index] || 0);
}
}
total += sum;
partialsum[i] = total;
}
}
else if (maxw == gw) {
for (i = vbox.g1; i <= vbox.g2; i++) {
sum = 0;
for (j = vbox.r1; j <= vbox.r2; j++) {
for (k = vbox.b1; k <= vbox.b2; k++) {
index = getColorIndex(j,i,k);
sum += (histo[index] || 0);
}
}
total += sum;
partialsum[i] = total;
}
}
else { /* maxw == bw */
for (i = vbox.b1; i <= vbox.b2; i++) {
sum = 0;
for (j = vbox.r1; j <= vbox.r2; j++) {
for (k = vbox.g1; k <= vbox.g2; k++) {
index = getColorIndex(j,k,i);
sum += (histo[index] || 0);
}
}
total += sum;
partialsum[i] = total;
}
}
partialsum.forEach(function(d,i) {
lookaheadsum[i] = total-d
});
function doCut(color) {
var dim1 = color + '1',
dim2 = color + '2',
left, right, vbox1, vbox2, d2, count2=0;
for (i = vbox[dim1]; i <= vbox[dim2]; i++) {
if (partialsum[i] > total / 2) {
vbox1 = vbox.copy();
vbox2 = vbox.copy();
left = i - vbox[dim1];
right = vbox[dim2] - i;
if (left <= right)
d2 = Math.min(vbox[dim2] - 1, ~~(i + right / 2));
else d2 = Math.max(vbox[dim1], ~~(i - 1 - left / 2));
// avoid 0-count boxes
while (!partialsum[d2]) d2++;
count2 = lookaheadsum[d2];
while (!count2 && partialsum[d2-1]) count2 = lookaheadsum[--d2];
// set dimensions
vbox1[dim2] = d2;
vbox2[dim1] = vbox1[dim2] + 1;
return [vbox1, vbox2];
}
}
}
// determine the cut planes
return maxw == rw ? doCut('r') :
maxw == gw ? doCut('g') :
doCut('b');
}
function quantize(pixels, maxcolors) {
// short-circuit
if (!pixels.length || maxcolors < 2 || maxcolors > 256) {
return new CMap();
}
// XXX: check color content and convert to grayscale if insufficient
var histo = getHisto(pixels),
histosize = 1 << (3 * sigbits);
// check that we aren't below maxcolors already
var nColors = 0;
histo.forEach(function() { nColors++ });
if (nColors <= maxcolors) {
// XXX: generate the new colors from the histo and return
}
// get the beginning vbox from the colors
var vbox = vboxFromPixels(pixels, histo),
pq = new PQueue(function(a,b) { return pv.naturalOrder(a.count(), b.count()) });
pq.push(vbox);
// inner function to do the iteration
function iter(lh, target) {
var ncolors = 1,
niters = 0,
vbox;
while (niters < maxIterations) {
vbox = lh.pop();
if (!vbox.count()) { /* just put it back */
lh.push(vbox);
niters++;
continue;
}
// do the cut
var vboxes = medianCutApply(histo, vbox),
vbox1 = vboxes[0],
vbox2 = vboxes[1];
if (!vbox1) {
return;
}
lh.push(vbox1);
if (vbox2) { /* vbox2 can be null */
lh.push(vbox2);
ncolors++;
}
if (ncolors >= target) return;
if (niters++ > maxIterations) {
return;
}
}
}
// first set of colors, sorted by population
iter(pq, fractByPopulations * maxcolors);
// Re-sort by the product of pixel occupancy times the size in color space.
var pq2 = new PQueue(function(a,b) {
return pv.naturalOrder(a.count()*a.volume(), b.count()*b.volume())
});
while (pq.size()) {
pq2.push(pq.pop());
}
// next set - generate the median cuts using the (npix * vol) sorting.
iter(pq2, maxcolors - pq2.size());
// calculate the actual colors
var cmap = new CMap();
while (pq2.size()) {
cmap.push(pq2.pop());
}
return cmap;
}
return {
quantize: quantize
}
})();
module.exports = ColorThief;
================================================
FILE: packages/image-palette-core/src/index.js
================================================
// @flow
import uniqBy from "lodash.uniqby";
import isEqual from "lodash.isequal";
import sortBy from "lodash.sortby";
import ColorThief from "./color-thief";
import Color from "color";
type ColorDescriptor = {
color: Color,
score: number,
contrast: number
};
type ColorPairings = Array;
type ColorPairingMap = {
[key: string]: ColorPairings
};
const THRESHOLD_CONTRAST_RATIO = 1.0;
// This is the minimum required for "AA" certification
const MINIMUM_CONTRAST_RATIO = 4.5;
const IDEAL_CONTRAST_RATIO = 7.5;
// Track the total number of pixels, reset everytime
// a palette is parsed.
let totalPixelCount = 0;
// Track pixel count by RGB values, reset everytime
// a palette is parsed.
let RGBToPixelCountMap = {};
/**
* The "range" is a metric used to determine how
* vibrant a color is. It checks the delta between
* the highest and lowest channel values, giving us an indiciation
* of how dominant one range might be.
*
* @example
* For the RGB value [250, 30, 10] we can see
* that the red channel dominates, meaning it will be
* primarily red.
*/
function getRGBRange(color: Color) {
var rgb = sortBy(color.rgb().array()).reverse();
var [max, med, min] = rgb;
return (max - min) / 10;
}
/**
* Returns a value between 0 and 1 representing how
* many pixels in the original image are represented
* by this color, 0 meaning none and 1 meaning all.
* @param {*} color
* @returns {number}
*/
function getPixelDominance(color: Color) {
const pixelCount: number = RGBToPixelCountMap[color];
return pixelCount / totalPixelCount;
}
/**
* Calculates the total score for each color
* in an array of pairs which are matches for some
* dominant color. Score represents viability, so higher is better.
* @param {*} pairs
* @returns {number}
*/
function calculateTotalPairScore(pairs) {
return pairs.reduce((score, color) => score + color.score, 0);
}
/**
* Return a new array of pairs, sorted by score.
* @param {*} pairs
*/
function sortPairsByScore(pairs: ColorPairings) {
pairs.sort((a, b) => {
if (a.score === b.score) {
return 0;
}
return a.score > b.score ? -1 : 1;
});
}
/**
* Dominance is ranked using a system that weighs
* each dominant color by three factors:
* - The true dominance of the color in the original image.
* This is determined by tracking the total number of pixels
* in the image, and the total pixels found for an image,
* and dividing the color pixels by the total.
*
* - The number of valid color pairs. If a color has no matching
* pairs it is given a score of zero, since we can't build
* a color palette with a single color.
*
* - The total score of each matching color. Each color is scored
* based on the contrast with the dominant color, the dominance
* in the original image, and its "range", which is the difference
* between the highest channel value and lowest, which sort of measures
* vibrance.
* @param {*} WCAGCompliantColorPairs
*/
function getMostDominantPrimaryColor(WCAGCompliantColorPairs: ColorPairingMap) {
var highestDominanceScore = 0;
var mostDominantColor = "";
for (var dominantColor in WCAGCompliantColorPairs) {
var pairs = WCAGCompliantColorPairs[dominantColor];
var dominance = getPixelDominance(dominantColor);
var totalPairScore = calculateTotalPairScore(pairs);
var score = pairs.length ? (pairs.length + totalPairScore) * dominance : 0;
if (score > highestDominanceScore) {
highestDominanceScore = score;
mostDominantColor = dominantColor;
}
}
sortPairsByScore(WCAGCompliantColorPairs[mostDominantColor]);
return mostDominantColor;
}
/**
* Gets the palette for an image from color-thief and maps
* the colors to Color instances. It also re-initializes
* and updates the RGBToPixelCountMap so we get a fresh
* dataset for pixel dominance
* @param {string} image
* @param {ColorThief} colorThief
*/
function getColorPalette(image, colorThief: ColorThief): Array {
totalPixelCount = 0;
RGBToPixelCountMap = {};
return colorThief.getPalette(image).map(color => {
var colorWrapper = new Color(color.rgb);
RGBToPixelCountMap[colorWrapper] = color.count;
totalPixelCount += color.count;
return colorWrapper;
});
}
/**
* The main export that takes an image URI and optional instance
* of color-thief and generates the palettes. Responsible for
* building the WCAGCompliantColorPairs map and generating
* accessible color pairings.
*
* Returns an object with a backgroundColor, color, and alternativeColor.
* If there's only one potential color pairing, alternativeColor will
* just be color.
* @param {*} image
* @param {*} colorThief
*/
export default function getImagePalette(image: string, colorThief: ColorThief) {
colorThief = colorThief || new ColorThief();
var palettes = getColorPalette(image, colorThief);
var highestMatchCount = 0;
var WCAGCompliantColorPairs: ColorPairingMap = {};
palettes.forEach((dominantColor, index) => {
var pairs = (WCAGCompliantColorPairs[dominantColor] = []);
palettes.forEach(color => {
var contrast = dominantColor.contrast(color);
if (contrast > THRESHOLD_CONTRAST_RATIO) {
/**
* The score is determined based three things:
*
* contrast:
* how well contrasted the color is with the dominant color.
* dominance:
* the level of dominance of the dominant color
* which is based on the index of the color in
* the palette array.
* range/vibrance:
* we want some vibrant colors
*/
var range = getRGBRange(color);
/**0
* If the contrast isn't high enough, lighten/darken
* the color so that we get a more accessible
* version of the color.
*/
if (contrast < MINIMUM_CONTRAST_RATIO) {
var delta = (MINIMUM_CONTRAST_RATIO - contrast) / 20;
var lighten = dominantColor.dark();
while (contrast < MINIMUM_CONTRAST_RATIO) {
var newColor = lighten ? color.lighten(delta) : color.darken(delta);
// If the new color is the same as the old one, we're not getting any
// lighter or darker so we need to stop.
if (newColor.hex() === color.hex()) {
break;
}
var newContrast = dominantColor.contrast(newColor);
// If the new contrast is lower than the old contrast
// then we need to start moving the other direction in the spectrum
if (newContrast < contrast) {
lighten = !lighten;
}
color = newColor;
contrast = newContrast;
}
}
var score = contrast + range;
pairs.push({ color, score, contrast });
}
});
});
var backgroundColor = getMostDominantPrimaryColor(WCAGCompliantColorPairs);
var [color, alternativeColor, accentColor] = WCAGCompliantColorPairs[
backgroundColor
];
if (!alternativeColor) {
alternativeColor = color;
}
if (!accentColor) {
accentColor = alternativeColor;
}
return {
backgroundColor,
color: color.color.hex(),
alternativeColor: alternativeColor.color.hex()
};
}
================================================
FILE: packages/preact-image-palette/.babelrc
================================================
{
"presets": [
["env", {
"modules": false
}]
],
"env": {
"commonjs": {
"presets": [
["env", {
"modules": "commonjs"
}]
]
}
}
}
================================================
FILE: packages/preact-image-palette/.npmignore
================================================
/*
!/lib
!/es
!/src
!LICENSE.txt
!README.md
!package.json
================================================
FILE: packages/preact-image-palette/README.md
================================================
# preact-image-palette
A Preact adpater for [`image-palette-core`](https://github.com/FormidableLabs/image-palette/tree/master/packages/image-palette-core)
### Install
```
npm install --save preact-image-palette
```
## Usage
The main export of the package is the `ImagePalette` component, which uses a [render callback](https://cdb.reacttraining.com/use-a-render-prop-50de598f11ce) to provide the color palette after the image is parsed.
```jsx
import ImagePalette from 'preact-image-palette'
const SomeComponent = ({ image }) => (
{({ backgroundColor, color, alternativeColor }) => (
This div has been themed based on
{image}
)}
)
```
## API
### Palette
See the [`image-palette-core` documentation](https://github.com/FormidableLabs/tree/master/packages/image-palette-core#the-palette)
### Props
Property | Type | Description
:-----------------------|:--------------|:--------------------------------
`image` | `String!` | The URL for the image to parse.
`crossOrigin` | `Boolean` | Sets the `crossOrigin` property on the `Image` instance that loads the source image 1
`render` | `Palette => ReactElement` | If you prefer to use a `render` prop over a function child, go for it! `react-image-palette` supports both.
`defaults` | `Palette` | A default palette to render if a palette cannot be parsed. This would typically occur when the source image fails to load
> 1 ⚠️ Keep in mind that the image will be loaded into a canvas and parsed as data, so you should only use images from trusted origins.
================================================
FILE: packages/preact-image-palette/__tests__/test.js
================================================
import {h, render, Component} from 'preact'
import PreactImagePalette from "../lib";
// Album cover for Com Truise - Fairlight
import testImage from "./fairlight.png";
class TestComponent extends Component {
render() {
const { render } = this.props;
return h(ReactImagePalette, { image: testImage }, render);
}
}
let container;
const renderWithExpect = (done, palette) => {
expect(palette.backgroundColor).to.equal("rgb(60, 16, 32)");
expect(palette.color).to.equal("#EF4E2E");
expect(palette.alternativeColor).to.equal("#D17872");
done();
// Return null so React doesn't throw an error
// about an empty return
return null;
};
describe("preact-image-palette", () => {
beforeEach(() => {
container = document.createElement("div");
});
describe("provider", () => {
it("should parse a palette from an image", done => {
render(
h(PreactImagePalette, {
image: testImage,
render: renderWithExpect.bind(this, done)
}),
container
);
});
it("should render defaults if the image fails to load", done => {
const defaults = {
backgroundColor: "red",
color: "white",
alternativeColor: "blue"
};
render(
h(PreactImagePalette, {
image: "unknown-image.gif",
defaults,
render: palette => {
expect(palette).to.equal(defaults);
done();
return null;
}
}),
container
);
});
});
});
================================================
FILE: packages/preact-image-palette/package.json
================================================
{
"name": "preact-image-palette",
"version": "0.1.1",
"description": "Create ARIA-compliant color themes based on any image.",
"main": "lib/index.js",
"module": "es/index.js",
"jsnext:main": "es/index.js",
"author": "Brandon Dail",
"license": "MIT",
"scripts": {
"build": "npm run clean && npm run build:es && npm run build:lib",
"build:es": "BABEL_ENV=es babel src --out-dir es",
"build:lib": "BABEL_ENV=commonjs babel src --out-dir lib",
"clean": "rimraf es lib",
"preversion": "npm run test",
"test:only": "karma start --single-run --browsers ChromeHeadless ../../karma.conf.js",
"test": "npm run build && npm run test:only"
},
"dependencies": {
"image-palette-core": "^0.2.2"
},
"devDependencies": {
"preact": "^8.0.0"
},
"peerDependencies": {
"preact": "^8.0.0"
}
}
================================================
FILE: packages/preact-image-palette/src/index.js
================================================
import ImagePaletteProvider from "./provider";
export default ImagePaletteProvider;
================================================
FILE: packages/preact-image-palette/src/provider.js
================================================
import {h, Component} from "preact";
import getImagePalette from "image-palette-core";
export default class ImagePaletteProvider extends Component {
constructor(...args) {
super(...args);
this.state = { colors: null };
this.onImageload = this.onImageload.bind(this);
this.onImageError = this.onImageError.bind(this);
}
componentDidMount() {
const image = (this.image = new Image());
image.crossOrigin = this.props.crossOrigin;
image.src = this.props.image;
image.onload = this.onImageload;
image.onerror = this.onImageError;
}
componentWillUnmount() {
this.image.onload = null;
this.image.onerror = null;
}
onImageload() {
var image = this.image;
var colors = getImagePalette(this.image);
this.setState({ colors });
}
onImageError() {
if (this.props.defaults) {
this.setState({ colors: this.props.defaults });
}
}
render() {
const { colors } = this.state;
const { children, render } = this.props;
const callback = render || children;
if (!callback) {
throw new Error(
"ImagePaletteProvider expects a render callback either as a child or via the `render` prop"
);
}
return colors ? callback(colors) : null;
}
}
================================================
FILE: packages/react-image-palette/.npmignore
================================================
/*
!/lib
!/es
!/src
!LICENSE.txt
!README.md
!package.json
================================================
FILE: packages/react-image-palette/README.md
================================================
# react-image-palette
A React adpater for [`image-palette-core`](https://github.com/FormidableLabs/image-palette/tree/master/packages/image-palette-core)
### Install
```
npm install --save react-image-palette
```
## Usage
The main export of the package is the `ImagePalette` component, which uses a [render callback](https://cdb.reacttraining.com/use-a-render-prop-50de598f11ce) to provide the color palette after the image is parsed.
```jsx
import ImagePalette from 'react-image-palette'
const SomeComponent = ({ image }) => (
{({ backgroundColor, color, alternativeColor }) => (
This div has been themed based on
{image}
)}
)
```
## API
### Palette
See the [`image-palette-core` documentation](https://github.com/FormidableLabs/image-palette/tree/master/packages/image-palette-core#the-palette)
### Props
Property | Type | Description
:-----------------------|:--------------|:--------------------------------
`image` | `String!` | The URL for the image to parse.
`crossOrigin` | `Boolean` | Sets the `crossOrigin` property on the `Image` instance that loads the source image 1
`render` | `Palette => ReactElement` | If you prefer to use a `render` prop over a function child, go for it! `react-image-palette` supports both.
`defaults` | `Palette` | A default palette to render if a palette cannot be parsed. This would typically occur when the source image fails to load
> 1 ⚠️ Keep in mind that the image will be loaded into a canvas and parsed as data, so you should only use images from trusted origins.
================================================
FILE: packages/react-image-palette/__tests__/test.js
================================================
import React from "react";
import ReactDOM from "react-dom";
import ReactImagePalette from "../lib";
// Album cover for Com Truise - Fairlight
import testImage from "./fairlight.png";
class TestComponent extends React.Component {
render() {
const { render } = this.props;
return React.createElement(ReactImagePalette, { image: testImage }, render);
}
}
let container;
const renderWithExpect = (done, palette) => {
expect(palette.backgroundColor).to.equal("rgb(60, 16, 32)");
expect(palette.color).to.equal("#EF4E2E");
expect(palette.alternativeColor).to.equal("#D17872");
done();
// Return null so React doesn't throw an error
// about an empty return
return null;
};
describe("react-image-palette", () => {
beforeEach(() => {
container = document.createElement("div");
});
describe("provider", () => {
it("should parse a palette from an image", done => {
ReactDOM.render(
React.createElement(ReactImagePalette, {
image: testImage,
render: renderWithExpect.bind(this, done)
}),
container
);
});
it("should render defaults if the image fails to load", done => {
const defaults = {
backgroundColor: "red",
color: "white",
alternativeColor: "blue"
};
ReactDOM.render(
React.createElement(ReactImagePalette, {
image: "unknown-image.gif",
defaults,
render: palette => {
expect(palette).to.equal(defaults);
done();
return null;
}
}),
container
);
});
});
});
================================================
FILE: packages/react-image-palette/package.json
================================================
{
"name": "react-image-palette",
"version": "0.2.4",
"description": "Create ARIA-compliant color themes based on any image.",
"main": "lib/index.js",
"module": "es/index.js",
"jsnext:main": "es/index.js",
"author": "Brandon Dail",
"license": "MIT",
"scripts": {
"build": "npm run clean && npm run build:es && npm run build:lib",
"build:es": "BABEL_ENV=es babel src --out-dir es",
"build:lib": "BABEL_ENV=commonjs babel src --out-dir lib",
"clean": "rimraf es lib",
"preversion": "npm run test",
"test:only": "karma start --single-run --browsers ChromeHeadless ../../karma.conf.js",
"test": "npm run build && npm run test:only"
},
"dependencies": {
"image-palette-core": "^0.2.2"
},
"devDependencies": {
"react-dom": "^16.1.0"
},
"peerDependencies": {
"react": "^15.0.0-0 || ^16.0.0-0"
}
}
================================================
FILE: packages/react-image-palette/src/index.js
================================================
import ImagePaletteProvider from "./provider";
export default ImagePaletteProvider;
================================================
FILE: packages/react-image-palette/src/provider.js
================================================
import React from "react";
import getImagePalette from "image-palette-core";
export default class ImagePaletteProvider extends React.Component {
constructor(...args) {
super(...args);
this.state = { colors: null };
this.onImageload = this.onImageload.bind(this);
this.onImageError = this.onImageError.bind(this);
}
componentDidMount() {
const image = (this.image = new Image());
image.crossOrigin = this.props.crossOrigin;
image.src = this.props.image;
image.onload = this.onImageload;
image.onerror = this.onImageError;
}
componentWillUnmount() {
this.image.onload = null;
this.image.onerror = null;
}
onImageload() {
var image = this.image;
var colors = getImagePalette(this.image);
this.setState({ colors });
}
onImageError() {
if (this.props.defaults) {
this.setState({ colors: this.props.defaults });
}
}
render() {
const { colors } = this.state;
const { children, render } = this.props;
const callback = render || children;
if (!callback) {
throw new Error(
"ImagePaletteProvider expects a render callback either as a child or via the `render` prop"
);
}
return colors ? callback(colors) : null;
}
}
