<!DOCTYPE html> <html class="reftest-wait"> <body> <img id="test"> </body> <script> var image = new Image; image.onload = function() { // Create a canvas. var canvas = document.createElement('canvas'); canvas.width = 100; canvas.height = 100; // Draw the image into the canvas. var ctx = canvas.getContext('2d'); ctx.drawImage(image, 0, 0); // Convert the image into a blob URI and use it as #test's src. canvas.toBlob(function(blob) { var uri = window.URL.createObjectURL(blob); var testImage = document.getElementById('test'); testImage.onload = testImage.onerror = function() { // Take the snapshot. document.documentElement.removeAttribute('class'); }; testImage.src = uri; }, 'image/jpeg', 0.99); } // Start loading the image. image.src = 'image.png'; </script> </html>