Retinize

canvas, img {
    image-rendering: optimizeSpeed;
    image-rendering: -o-crisp-edges;
    image-rendering: -moz-crisp-edges;
    image-rendering: optimize-contrast;
    image-rendering: -webkit-optimize-contrast;
    image-rendering: pixelated; /* CSS4 */
    -ms-interpolation-mode: nearest-neighbor;
}