Unusable with picajs

[yann86]

Hi,

Thanks for your code it's very usefull, however I can't use it with picajs.

In my app I use pica js for resizing pictures, when I use your polyfill I have an error:

[Pica: cannot use getImageData on canvas, make sure fingerprinting protection isn't enabled]

Internally pica use this code to check if browser block fingerprinting with getImageData

function can_use_canvas(createCanvas) {
  var usable = false;

  try {
    var canvas = createCanvas(2, 1);
    var ctx = canvas.getContext('2d');
    var d = ctx.createImageData(2, 1);
    d.data[0] = 12;
    d.data[1] = 23;
    d.data[2] = 34;
    d.data[3] = 255;
    d.data[4] = 45;
    d.data[5] = 56;
    d.data[6] = 67;
    d.data[7] = 255;
    ctx.putImageData(d, 0, 0);
    d = null;
    d = ctx.getImageData(0, 0, 2, 1);

    if (d.data[0] === 12 && d.data[1] === 23 && d.data[2] === 34 && d.data[3] === 255 && d.data[4] === 45 && d.data[5] === 56 && d.data[6] === 67 && d.data[7] === 255) {
      usable = true;
    }
  } catch (err) {}

  return usable;
};

function createCanvas(width, height) {
  var tmpCanvas = document.createElement('canvas');
  tmpCanvas.width = width;
  tmpCanvas.height = height;
  return tmpCanvas;
}
can_use_canvas(createCanvas)

Can you help me with this issue I really would like to use your polyfill with picajs