draw_array_to_canvas.js

  width = 256;
  height = 256;
  let dst = new Uint8Array(Module.HEAPU8.buffer, dst_ptr, width * height);

  canvasResultsLenna.width = width;
  canvasResultsLenna.height = height;

  var imgData = ctxResultsLenna.createImageData(width, height);
  for (var i = 0; i < dst.length; i++) {
    imgData.data[i * 4] = dst[i];
    imgData.data[i * 4 + 1] = dst[i];
    imgData.data[i * 4 + 2] = dst[i];
    imgData.data[i * 4 + 3] = 255;
  }
  console.log(imgData);

  ctxResultsLenna.putImageData(imgData, 0, 0);