text: /* canvas-toBlob.js
   * A canvas.toBlob() implementation.
   * 2013-12-27
   * 
   * By Eli Grey, http://eligrey.com and Devin Samarin, https://github.com/eboyjr
   * License: X11/MIT
   *   See https://github.com/eligrey/canvas-toBlob.js/blob/master/LICENSE.md
   */
  
  /*global self */
  /*jslint bitwise: true, regexp: true, confusion: true, es5: true, vars: true, white: true,
    plusplus: true */
  
  /*! @source http://purl.eligrey.com/github/canvas-toBlob.js/blob/master/canvas-toBlob.js */
  
  (function(view) {
  "use strict";
  var
      Uint8Array = view.Uint8Array
    , HTMLCanvasElement = view.HTMLCanvasElement
    , canvas_proto = HTMLCanvasElement && HTMLCanvasElement.prototype
    , is_base64_regex = /\s*;\s*base64\s*(?:;|$)/i
    , to_data_url = "toDataURL"
    , base64_ranks
    , decode_base64 = function(base64) {
      var
          len = base64.length
        , buffer = new Uint8Array(len / 4 * 3 | 0)
        , i = 0
        , outptr = 0
        , last = [0, 0]
        , state = 0
        , save = 0
        , rank
        , code
        , undef
      ;
      while (len--) {
        code = base64.charCodeAt(i++);
        rank = base64_ranks[code-43];
        if (rank !== 255 && rank !== undef) {
          last[1] = last[0];
          last[0] = code;
          save = (save << 6) | rank;
          state++;
          if (state === 4) {
            buffer[outptr++] = save >>> 16;
            if (last[1] !== 61 /* padding character */) {
              buffer[outptr++] = save >>> 8;
            }
            if (last[0] !== 61 /* padding character */) {
              buffer[outptr++] = save;
            }
            state = 0;
          }
        }
      }
      // 2/3 chance there's going to be some null bytes at the end, but that
      // doesn't really matter with most image formats.
      // If it somehow matters for you, truncate the buffer up outptr.
      return buffer;
    }
  ;
  if (Uint8Array) {
    base64_ranks = new Uint8Array([
        62, -1, -1, -1, 63, 52, 53, 54, 55, 56, 57, 58, 59, 60, 61, -1
      , -1, -1,  0, -1, -1, -1,  0,  1,  2,  3,  4,  5,  6,  7,  8,  9
      , 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25
      , -1, -1, -1, -1, -1, -1, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35
      , 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51
    ]);
  }
  if (HTMLCanvasElement && !canvas_proto.toBlob) {
    canvas_proto.toBlob = function(callback, type /*, ...args*/) {
        if (!type) {
        type = "image/png";
      } if (this.mozGetAsFile) {
        callback(this.mozGetAsFile("canvas", type));
        return;
      } if (this.msToBlob && /^\s*image\/png\s*(?:$|;)/i.test(type)) {
        callback(this.msToBlob());
        return;
      }
  
      var
          args = Array.prototype.slice.call(arguments, 1)
        , dataURI = this[to_data_url].apply(this, args)
        , header_end = dataURI.indexOf(",")
        , data = dataURI.substring(header_end + 1)
        , is_base64 = is_base64_regex.test(dataURI.substring(0, header_end))
        , blob
      ;
      if (Blob.fake) {
        // no reason to decode a data: URI that's just going to become a data URI again
        blob = new Blob
        if (is_base64) {
          blob.encoding = "base64";
        } else {
          blob.encoding = "URI";
        }
        blob.data = data;
        blob.size = data.length;
      } else if (Uint8Array) {
        if (is_base64) {
          blob = new Blob([decode_base64(data)], {type: type});
        } else {
          blob = new Blob([decodeURIComponent(data)], {type: type});
        }
      }
      callback(blob);
    };
  
    if (canvas_proto.toDataURLHD) {
      canvas_proto.toBlobHD = function() {
        to_data_url = "toDataURLHD";
        var blob = this.toBlob();
        to_data_url = "toDataURL";
        return blob;
      }
    } else {
      canvas_proto.toBlobHD = canvas_proto.toBlob;
    }
  }
  }(typeof self !== "undefined" && self || typeof window !== "undefined" && window || this.content || this));
  