Shadow - Fabric.js

HTML

<canvas id="c" width="350" height="150">
</canvas>

CSS

#c {
  border: 2px red solid;
  transform: matrix3d(0.737119, 0, 0, -0.000503604, 0, 1.14946, 0, 0.000868964, 0, 0, 1, 0, 0, 0, 0, 1);
}

JavaScript

var canvas = new fabric.Canvas('c');

fabric.Image.fromURL('http://placehold.it/350x150', function(img) {

  canvas.add(img);
 
  // -- encode64 as a PNG --
  var png = canvas.toDataURL({
    format: 'png',
  });
  console.log(png);

}, {
  crossOrigin: 'anonymous'
});