canvas-toBlob.js implements the standard HTML5 canvas.toBlob() and
canvas.toBlobHD() methods in browsers that do not natively support it. canvas-toBlob.js
requires Blob support to function, which is not present in all browsers. Blob.js
is a cross-browser Blob implementation that solves this.
canvas-toBlob.js has the same browser support as FileSaver.js.
