<img> tag to data uri

gistfile1.js

// var originalImage = document.querySelector('img');// ...
var canvas = document.createElement('canvas'),
    context, dataURI;

canvas.width  = originalImage.width;
canvas.height = originalImage.height;

context = canvas.getContext('2d');
context.drawImage(originalImage, 0, 0);
dataURI = canvas.toDataURL('image/png');

delete canvas;