n1k0

var page = new WebPage(),
    address, output, size;
    
//capture and captureSelector functions adapted from CasperJS - https://github.com/n1k0/casperjs
capture = function(targetFile, clipRect) {
    var previousClipRect;
    var clipRect = {top: 0, left:0, width: 40, height: 40};
    if (clipRect) {
        if (!isType(clipRect, "object")) {
            throw new Error("clipRect must be an Object instance.");

jonleighton

// Converts an ArrayBuffer directly to base64, without any intermediate 'convert to string then
// use window.btoa' step. According to my tests, this appears to be a faster approach:
// http://jsperf.com/encoding-xhr-image-data/5

/*
MIT LICENSE

Copyright 2011 Jon Leighton

Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions: