gistfile1.js

function(dataURI) {
	var byteString;

	//Convert base64 to raw binary data
	if (dataURI.split(',')[0].indexOf('base64') >= 0) {
		byteString = atob(dataURI.split(',')[1]);
	} else {
		byteString = unescape(dataURI.split(',')[1]);
	}
	
	//Get the mime type
	var mimeString = dataURI.split(',')[0].split(':')[1].split(';')[0];
	
	//Write the binary data to an ArrayBuffer
	var arrayBuffer = new ArrayBuffer(byteString.length);
	var ia = new Uint8Array(arrayBuffer);
	for (var i = 0; i < byteString.length; i++) {
		ia[i] = byteString.charCodeAt(i);
	}

	//Write the ArrayBuffer to a Blob
	var blob;
	try {
		blob = new Blob([ia], {type: mimeString});
	} catch (e) {
		//The BlobBuilder API has been deprecated in favor
		//of Blob. This is for backwards compatibility.
		var BlobBuilder = window.WebKitBlobBuilder || window.MozBlobBuilder;
		var bb = new BlobBuilder();
		bb.append(ia);
		blob = bb.getBlob(mimeString);
	}
		
	var image = document.createElement('img');
	image.src = 'data:'+mimeString+';base64,'+btoa(blob);
	document.body.appendChild(image);
}