quora-js-progressive-image-loading.js

// draw the data-uri image on the canvas
function a(e) {
    if (e.getAttribute("data-src")) {
        var t = new Image;
        t.src = e.getAttribute("data-src");
        var i = e.getAttribute("width")
          , n = e.getAttribute("height")
          , o = e.getContext("2d");
        t.addEventListener("load", function() {
            o.drawImage(t, 0, 0, i, n)
        }, false)
    }
}
// go through all canvas on the page with a data-src
function r() {
    var e = document.querySelectorAll("canvas[data-src]");
    d.insertionQ("canvas[data-src]").every(function(e) {
        a(e)
    }),
    [].forEach.call(e, a)
}