var canvas = document.createElement('canvas');

var height = 200;

var width  = 200;

canvas.width  = width;

canvas.height = height;

var ctx = canvas.getContext('2d');

var img = document.getElementById("img001");

ctx.drawImage(img, 0, 0);

​

canvas.toBlob(function (blob) {

  var reader = new FileReader();

​

  reader.onloadend = function () {

    console.log(reader.result);

  };

​

  reader.readAsBinaryString(blob);

});