Anonymous user
Percentage difference between images: Difference between revisions
no edit summary
(→{{header|zkl}}: verbiage) |
No edit summary |
||
Line 723:
}
}</lang>
=={{header|JavaScript}}==
<lang javascript>function getImageData(url, callback) {
var img = document.createElement('img');
var canvas = document.createElement('canvas');
img.onload = function () {
canvas.width = img.width;
canvas.height = img.height;
var ctx = canvas.getContext('2d');
ctx.drawImage(img, 0, 0);
callback(ctx.getImageData(0, 0, img.width, img.height));
};
img.src = url;
}
function compare(firstImage, secondImage, callback) {
getImageData(firstImage, function (img1) {
getImageData(secondImage, function (img2) {
if (img1.width !== img2.width || img1.height != img2.height) {
callback(NaN);
return;
}
var diff = 0;
for (var i = 0; i < img1.data.length / 4; i++) {
diff += Math.abs(img1.data[4 * i + 0] - img2.data[4 * i + 0]) / 255;
diff += Math.abs(img1.data[4 * i + 1] - img2.data[4 * i + 1]) / 255;
diff += Math.abs(img1.data[4 * i + 2] - img2.data[4 * i + 2]) / 255;
}
callback(100 * diff / (img1.width * img1.height * 3));
});
});
}
compare('Lenna50.jpg', 'Lenna100.jpg', function (result) {
console.log(result);
});</lang>
=={{header|Liberty BASIC}}==
| |||