https://www.npmjs.com/package/pixelmatch
此腳本不應該直接安裝，它是一個供其他腳本使用的函式庫。欲使用本函式庫，請在腳本 metadata 寫上： // @require https://update.greasyfork.org/scripts/498926/1400611/pixelmatch%40530.js
window.pixelmatch = (() => {
var __getOwnPropNames = Object.getOwnPropertyNames;
var __commonJS = (cb, mod) => function __require() {
return mod || (0, cb[__getOwnPropNames(cb)[0]])((mod = { exports: {} }).exports, mod), mod.exports;
};
// entry.js
var require_entry = __commonJS({
"entry.js"(exports, module) {
module.exports = pixelmatch;
var defaultOptions = {
threshold: 0.1,
// matching threshold (0 to 1); smaller is more sensitive
includeAA: false,
// whether to skip anti-aliasing detection
alpha: 0.1,
// opacity of original image in diff output
aaColor: [255, 255, 0],
// color of anti-aliased pixels in diff output
diffColor: [255, 0, 0],
// color of different pixels in diff output
diffColorAlt: null,
// whether to detect dark on light differences between img1 and img2 and set an alternative color to differentiate between the two
diffMask: false
// draw the diff over a transparent background (a mask)
};
function pixelmatch(img1, img2, output, width, height, options) {
if (!isPixelData(img1) || !isPixelData(img2) || output && !isPixelData(output))
throw new Error("Image data: Uint8Array, Uint8ClampedArray or Buffer expected.");
if (img1.length !== img2.length || output && output.length !== img1.length)
throw new Error("Image sizes do not match.");
if (img1.length !== width * height * 4) throw new Error("Image data size does not match width/height.");
options = Object.assign({}, defaultOptions, options);
const len = width * height;
const a32 = new Uint32Array(img1.buffer, img1.byteOffset, len);
const b32 = new Uint32Array(img2.buffer, img2.byteOffset, len);
let identical = true;
for (let i = 0; i < len; i++) {
if (a32[i] !== b32[i]) {
identical = false;
break;
}
}
if (identical) {
if (output && !options.diffMask) {
for (let i = 0; i < len; i++) drawGrayPixel(img1, 4 * i, options.alpha, output);
}
return 0;
}
const maxDelta = 35215 * options.threshold * options.threshold;
let diff = 0;
for (let y = 0; y < height; y++) {
for (let x = 0; x < width; x++) {
const pos = (y * width + x) * 4;
const delta = colorDelta(img1, img2, pos, pos);
if (Math.abs(delta) > maxDelta) {
if (!options.includeAA && (antialiased(img1, x, y, width, height, img2) || antialiased(img2, x, y, width, height, img1))) {
if (output && !options.diffMask) drawPixel(output, pos, ...options.aaColor);
} else {
if (output) {
drawPixel(output, pos, ...delta < 0 && options.diffColorAlt || options.diffColor);
}
diff++;
}
} else if (output) {
if (!options.diffMask) drawGrayPixel(img1, pos, options.alpha, output);
}
}
}
return diff;
}
function isPixelData(arr) {
return ArrayBuffer.isView(arr) && arr.constructor.BYTES_PER_ELEMENT === 1;
}
function antialiased(img, x1, y1, width, height, img2) {
const x0 = Math.max(x1 - 1, 0);
const y0 = Math.max(y1 - 1, 0);
const x2 = Math.min(x1 + 1, width - 1);
const y2 = Math.min(y1 + 1, height - 1);
const pos = (y1 * width + x1) * 4;
let zeroes = x1 === x0 || x1 === x2 || y1 === y0 || y1 === y2 ? 1 : 0;
let min = 0;
let max = 0;
let minX, minY, maxX, maxY;
for (let x = x0; x <= x2; x++) {
for (let y = y0; y <= y2; y++) {
if (x === x1 && y === y1) continue;
const delta = colorDelta(img, img, pos, (y * width + x) * 4, true);
if (delta === 0) {
zeroes++;
if (zeroes > 2) return false;
} else if (delta < min) {
min = delta;
minX = x;
minY = y;
} else if (delta > max) {
max = delta;
maxX = x;
maxY = y;
}
}
}
if (min === 0 || max === 0) return false;
return hasManySiblings(img, minX, minY, width, height) && hasManySiblings(img2, minX, minY, width, height) || hasManySiblings(img, maxX, maxY, width, height) && hasManySiblings(img2, maxX, maxY, width, height);
}
function hasManySiblings(img, x1, y1, width, height) {
const x0 = Math.max(x1 - 1, 0);
const y0 = Math.max(y1 - 1, 0);
const x2 = Math.min(x1 + 1, width - 1);
const y2 = Math.min(y1 + 1, height - 1);
const pos = (y1 * width + x1) * 4;
let zeroes = x1 === x0 || x1 === x2 || y1 === y0 || y1 === y2 ? 1 : 0;
for (let x = x0; x <= x2; x++) {
for (let y = y0; y <= y2; y++) {
if (x === x1 && y === y1) continue;
const pos2 = (y * width + x) * 4;
if (img[pos] === img[pos2] && img[pos + 1] === img[pos2 + 1] && img[pos + 2] === img[pos2 + 2] && img[pos + 3] === img[pos2 + 3]) zeroes++;
if (zeroes > 2) return true;
}
}
return false;
}
function colorDelta(img1, img2, k, m, yOnly) {
let r1 = img1[k + 0];
let g1 = img1[k + 1];
let b1 = img1[k + 2];
let a1 = img1[k + 3];
let r2 = img2[m + 0];
let g2 = img2[m + 1];
let b2 = img2[m + 2];
let a2 = img2[m + 3];
if (a1 === a2 && r1 === r2 && g1 === g2 && b1 === b2) return 0;
if (a1 < 255) {
a1 /= 255;
r1 = blend(r1, a1);
g1 = blend(g1, a1);
b1 = blend(b1, a1);
}
if (a2 < 255) {
a2 /= 255;
r2 = blend(r2, a2);
g2 = blend(g2, a2);
b2 = blend(b2, a2);
}
const y1 = rgb2y(r1, g1, b1);
const y2 = rgb2y(r2, g2, b2);
const y = y1 - y2;
if (yOnly) return y;
const i = rgb2i(r1, g1, b1) - rgb2i(r2, g2, b2);
const q = rgb2q(r1, g1, b1) - rgb2q(r2, g2, b2);
const delta = 0.5053 * y * y + 0.299 * i * i + 0.1957 * q * q;
return y1 > y2 ? -delta : delta;
}
function rgb2y(r, g, b) {
return r * 0.29889531 + g * 0.58662247 + b * 0.11448223;
}
function rgb2i(r, g, b) {
return r * 0.59597799 - g * 0.2741761 - b * 0.32180189;
}
function rgb2q(r, g, b) {
return r * 0.21147017 - g * 0.52261711 + b * 0.31114694;
}
function blend(c, a) {
return 255 + (c - 255) * a;
}
function drawPixel(output, pos, r, g, b) {
output[pos + 0] = r;
output[pos + 1] = g;
output[pos + 2] = b;
output[pos + 3] = 255;
}
function drawGrayPixel(img, i, alpha, output) {
const r = img[i + 0];
const g = img[i + 1];
const b = img[i + 2];
const val = blend(rgb2y(r, g, b), alpha * img[i + 3] / 255);
drawPixel(output, i, val, val, val);
}
}
});
return require_entry();
})();