Greasy Fork is available in English.
Maps the drawing's colors to the current color palette.
// ==UserScript==
// @name Style Transfer
// @namespace https://greasyfork.org/users/281093
// @match https://sketchful.io/
// @grant none
// @version 2.1
// @author Bell
// @license MIT
// @copyright 2020, Bell
// @description Maps the drawing's colors to the current color palette.
// ==/UserScript==
/* jshint esversion: 6 */
const workerCode = `
let colorCache = [];
let palette = [];
let paletteLab = [];
let delta00;
const canvas = {
width: 800,
height: 600
}
self.onmessage = process;
function process(e) {
colorCache = [];
paletteLab = [];
let imgData = e.data.imgData;
let fast = e.data.options.fast;
let toDither = e.data.options.dither;
let useWhite = e.data.options.white;
palette = e.data.palette;
delta00 = e.data.options.deltaE00;
let data = imgData.data;
palette.forEach(rgb => {
paletteLab.push(rgb2lab(rgb));
});
let closestColor;
for (let y = 0; y < canvas.height; y++) {
for (let x = 0; x < canvas.width; x++) {
let i = getIndex(x, y);
let rgb = data.slice(i, i + 3);
if (useWhite) {
if (rgb[0] === 255 && rgb[1] === 255 && rgb[2] === 255) continue;
}
closestColor = isCached(rgb) || findClosest(fast, rgb);
setPixel(data, closestColor, i);
if (toDither)
dither(data, rgb, closestColor, x, y);
}
}
postMessage(imgData);
}
function dither(data, rgb, closestColor, x, y) {
let quantError = getQuantError(rgb, closestColor);
i = getIndex(x + 1, y);
rgb = data.slice(i, i + 3);
setPixel(data, getQuantColor(rgb, quantError, 7/16), i);
i = getIndex(x - 1, y + 1);
rgb = data.slice(i, i + 3);
setPixel(data, getQuantColor(rgb, quantError, 3/16), i);
i = getIndex(x, y + 1);
rgb = data.slice(i, i + 3);
setPixel(data, getQuantColor(rgb, quantError, 5/16), i);
i = getIndex(x + 1, y + 1);
rgb = data.slice(i, i + 3);
setPixel(data, getQuantColor(rgb, quantError, 1/16), i);
}
function getQuantError(oldColor, newColor) {
return [
oldColor[0] - newColor[0],
oldColor[1] - newColor[1],
oldColor[2] - newColor[2]
];
}
function getQuantColor(color, error, scale) {
return [
color[0] + error[0] * scale,
color[1] + error[1] * scale,
color[2] + error[2] * scale
];
}
function setPixel(data, newPixel, index) {
data[index] = newPixel[0];
data[index + 1] = newPixel[1];
data[index + 2] = newPixel[2];
}
function rgbValue(data, x, y, c) {
return data[((y * (4 * canvas.width)) + (4 * x)) + c];
}
function getIndex(x, y) {
return ((y * (4 * canvas.width)) + (4 * x));
}
function findClosest(fast, rgb) {
let closestIndex = fast ? findClosestFast(rgb) : findClosestSlow(rgb);
cacheColor(rgb, closestIndex);
return palette[closestIndex];
}
function findClosestFast(rgb) {
let closest = {};
palette.forEach((color, index) => {
let distance = ((color[0] - rgb[0]) * 0.30) ** 2 +
((color[1] - rgb[1]) * 0.59) ** 2+
((color[2] - rgb[2]) * 0.11) ** 2;
if (index === 0 || distance < closest.dist) {
closest = {
dist: distance,
idx: index
};
}
});
return closest.idx;
}
function findClosestSlow(rgb) {
let closest = {};
let labColor = rgb2lab(rgb);
paletteLab.forEach((color, index) => {
let distance = delta00 ? deltaE00(labColor, color) :
deltaE(labColor, color);
if (index === 0 || distance < closest.dist) {
closest = {
dist: distance,
idx: index
};
}
});
return closest.idx;
}
function cacheColor(rgb, index) {
if (colorCache.length > 127) return;
colorCache.push({
idx: index,
color: rgb
});
}
function isCached(rgb) {
for (let cached of colorCache) {
if (cached.color[0] === rgb[0] && cached.color[1] === rgb[1] &&
cached.color[2] === rgb[2]) {
return palette[cached.idx];
}
}
return false;
}
function deltaE(labA, labB) {
let deltaL = labA[0] - labB[0];
let deltaA = labA[1] - labB[1];
let deltaB = labA[2] - labB[2];
let c1 = Math.sqrt(labA[1] * labA[1] + labA[2] * labA[2]);
let c2 = Math.sqrt(labB[1] * labB[1] + labB[2] * labB[2]);
let deltaC = c1 - c2;
let deltaH = deltaA * deltaA + deltaB * deltaB - deltaC * deltaC;
deltaH = deltaH < 0 ? 0 : Math.sqrt(deltaH);
let sc = 1.0 + 0.045 * c1;
let sh = 1.0 + 0.015 * c1;
let deltaLKlsl = deltaL / (1.0);
let deltaCkcsc = deltaC / (sc);
let deltaHkhsh = deltaH / (sh);
let i = deltaLKlsl * deltaLKlsl + deltaCkcsc * deltaCkcsc + deltaHkhsh * deltaHkhsh;
return i < 0 ? 0 : Math.sqrt(i);
}
function rgb2lab(rgb) {
let r = rgb[0] / 255,
g = rgb[1] / 255,
b = rgb[2] / 255,
x, y, z;
r = (r > 0.04045) ? ((r + 0.055) / 1.055) ** 2.4 : r / 12.92;
g = (g > 0.04045) ? ((g + 0.055) / 1.055) ** 2.4 : g / 12.92;
b = (b > 0.04045) ? ((b + 0.055) / 1.055) ** 2.4 : b / 12.92;
x = (r * 0.4124 + g * 0.3576 + b * 0.1805) / 0.95047;
y = (r * 0.2126 + g * 0.7152 + b * 0.0722) / 1.00000;
z = (r * 0.0193 + g * 0.1192 + b * 0.9505) / 1.08883;
x = (x > 0.008856) ? x ** (1 / 3) : (7.787 * x) + 16 / 116;
y = (y > 0.008856) ? y ** (1 / 3) : (7.787 * y) + 16 / 116;
z = (z > 0.008856) ? z ** (1 / 3) : (7.787 * z) + 16 / 116;
return [(116 * y) - 16, 500 * (x - y), 200 * (y - z)];
}
function deltaE00(labA, labB) {
const [l1, a1, b1] = labA;
const [l2, a2, b2] = labB;
Math.rad2deg = function(rad) {
return 360 * rad / (2 * Math.PI);
};
Math.deg2rad = function(deg) {
return (2 * Math.PI * deg) / 360;
};
const avgL = (l1 + l2) / 2;
const C1 = Math.sqrt(Math.pow(a1, 2) + Math.pow(b1, 2));
const C2 = Math.sqrt(Math.pow(a2, 2) + Math.pow(b2, 2));
const avgC = (C1 + C2) / 2;
const G = (1 - Math.sqrt(Math.pow(avgC, 7) / (Math.pow(avgC, 7) + Math.pow(25, 7)))) / 2;
const A1p = a1 * (1 + G);
const A2p = a2 * (1 + G);
const C1p = Math.sqrt(Math.pow(A1p, 2) + Math.pow(b1, 2));
const C2p = Math.sqrt(Math.pow(A2p, 2) + Math.pow(b2, 2));
const avgCp = (C1p + C2p) / 2;
let h1p = Math.rad2deg(Math.atan2(b1, A1p));
if (h1p < 0) {
h1p = h1p + 360;
}
let h2p = Math.rad2deg(Math.atan2(b2, A2p));
if (h2p < 0) {
h2p = h2p + 360;
}
const avghp = Math.abs(h1p - h2p) > 180 ? (h1p + h2p + 360) / 2 : (h1p + h1p) / 2;
const T = 1 - 0.17 * Math.cos(Math.deg2rad(avghp - 30)) + 0.24 * Math.cos(Math.deg2rad(2 * avghp)) + 0.32 * Math.cos(Math.deg2rad(3 * avghp + 6)) - 0.2 * Math.cos(Math.deg2rad(4 * avghp - 63));
let deltahp = h2p - h1p;
if (Math.abs(deltahp) > 180) {
if (h2p <= h1p) {
deltahp += 360;
} else {
deltahp -= 360;
}
}
const delta_lp = l2 - l1;
const delta_cp = C2p - C1p;
deltahp = 2 * Math.sqrt(C1p * C2p) * Math.sin(Math.deg2rad(deltahp) / 2);
const Sl = 1 + ((0.015 * Math.pow(avgL - 50, 2)) / Math.sqrt(20 + Math.pow(avgL - 50, 2)));
const Sc = 1 + 0.045 * avgCp;
const Sh = 1 + 0.015 * avgCp * T;
const deltaro = 30 * Math.exp(-(Math.pow((avghp - 275) / 25, 2)));
const Rc = 2 * Math.sqrt(Math.pow(avgCp, 7) / (Math.pow(avgCp, 7) + Math.pow(25, 7)));
const Rt = -Rc * Math.sin(2 * Math.deg2rad(deltaro));
const kl = 1;
const kc = 1;
const kh = 1;
const deltaE = Math.sqrt(Math.pow(delta_lp / (kl * Sl), 2) + Math.pow(delta_cp / (kc * Sc), 2) + Math.pow(deltahp / (kh * Sh), 2) + Rt * (delta_cp / (kc * Sc)) * (deltahp / (kh * Sh)));
return deltaE;
}
`;
const canvas = document.querySelector('#canvas');
const ctx = canvas.getContext('2d');
const colorButtons = document.querySelectorAll('.gameToolsColor');
const interfaceBar = document.querySelector('#gameInterface');
const container = document.createElement('div');
const fastButton = document.createElement('button');
const slowButton = document.createElement('button');
const ditherText = document.createElement('label');
const ditherCheckbox = document.createElement('input');
const whiteText = document.createElement('label');
const whiteCheckbox = document.createElement('input');
const deltaE00Text = document.createElement('label');
const deltaE00Checkbox = document.createElement('input');
const spinner = document.createElement('img');
let palette = [];
const dataWorker = createWorker(workerCode);
(function init() {
canvas.save = () => {
canvas.dispatchEvent(new MouseEvent('pointerup', {
bubbles: true,
clientX: 0,
clientY: 0,
button: 0
}));
};
initInterface();
initListeners();
})();
function createWorker(content) {
const workerBlob = new Blob([content], {
'type': 'text/javascript'
});
const blobURL = window.URL.createObjectURL(workerBlob);
return new Worker(blobURL);
}
function initListeners() {
dataWorker.onmessage = (e) => {
spinner.remove();
canvas.style.filter = '';
ctx.putImageData(e.data, 0, 0);
canvas.save();
};
fastButton.onpointerdown = () => {
transformColor(true);
};
slowButton.onpointerdown = () => {
transformColor(false);
};
}
function transformColor(fast) {
getPalette();
const imgData = ctx.getImageData(0, 0, canvas.width, canvas.height);
const options = {
fast: fast,
dither: ditherCheckbox.checked,
white: whiteCheckbox.checked,
deltaE00: deltaE00Checkbox.checked
};
canvas.style.filter = 'brightness(0.5)';
canvas.parentElement.insertBefore(spinner, canvas);
dataWorker.postMessage({ imgData: imgData, palette: palette, options: options });
}
function getPalette() {
palette = whiteCheckbox.checked ? [[255, 255, 255]] : [];
paletteLab = [];
colorCache = [];
colorButtons.forEach(color => {
if (color.style.background === 'rgb(255, 255, 255)') return;
palette.push(color.style.background.substring(4, color.style.background.length - 1)
.replace(/ /g, '').split(',').map(x => parseInt(x)));
});
}
function canvasVisibility() {
if (isFreeDraw()) container.style.display = '';
else container.style.display = 'none';
}
const canvasObserver = new MutationObserver(canvasVisibility);
canvasObserver.observe(document.querySelector('body > div.game'), {
attributes: true
});
canvasObserver.observe(canvas, {
attributes: true
});
function isFreeDraw() {
return canvas.style.display !== 'none' &&
document.querySelector('#gameClock').style.display === 'none' &&
document.querySelector('#gameSettings').style.display === 'none';
}
function initInterface() {
container.style.margin = 'auto';
container.style.color = '#737373';
container.style.userSelect = 'none';
container.style.padding = '9px';
fastButton.setAttribute('class', 'btn btn-sm btn-primary');
fastButton.style.marginRight = '5px';
slowButton.setAttribute('class', 'btn btn-sm btn-primary');
slowButton.style.marginRight = '5px';
ditherCheckbox.type = 'checkbox';
ditherCheckbox.style.marginRight = '5px';
ditherCheckbox.id = 'dither';
ditherCheckbox.name = 'dither';
ditherText.textContent = 'spatter';
ditherText.style.marginRight = '5px';
ditherText.setAttribute('for', 'dither');
whiteCheckbox.type = 'checkbox';
whiteCheckbox.style.marginRight = '5px';
whiteCheckbox.id = 'white';
whiteCheckbox.name = 'white';
whiteText.textContent = 'white';
whiteText.style.marginRight = '5px';
whiteText.setAttribute('for', 'white');
deltaE00Checkbox.type = 'checkbox';
deltaE00Checkbox.style.marginRight = '5px';
deltaE00Checkbox.id = 'deltaE00';
deltaE00Checkbox.name = 'deltaE00';
deltaE00Text.textContent = 'deltaE00';
deltaE00Text.style.marginRight = '5px';
deltaE00Text.setAttribute('for', 'deltaE00');
fastButton.textContent = 'FAST';
slowButton.textContent = 'ACCURATE';
spinner.style.position = 'absolute';
spinner.style.width = '100px';
spinner.style.zIndex = '1';
spinner.src = '/res/svg/spinner.svg';
container.append(fastButton, slowButton, ditherCheckbox, ditherText,
whiteCheckbox, whiteText);
interfaceBar.appendChild(container);
}