#canvas {
  display: block;
  width: 320px;
  height: 320px;
  margin: auto;
  image-rendering: optimizeSpeed;
  image-rendering: -moz-crisp-edges;
  image-rendering: -webkit-optimize-contrast;
  image-rendering: -o-crisp-edges;
  image-rendering: pixelated;
  -ms-interpolation-mode: nearest-neighbor;
}