Disable image smoothing. Comes in handy when creating pixel-art game. The pixels will stay sharp.

css

/* You can aslo add */
canvas {
    image-rendering: optimizeSpeed;
    image-rendering: -moz-crisp-edges;
    image-rendering: -webkit-optimize-contrast;
    image-rendering: optimize-contrast;
    -ms-interpolation-mode: nearest-neighbor;
}

no-image-smooth

var context = canvas.getContext('2d');
context.webkitImageSmoothingEnabled = false;
context.mozImageSmoothingEnabled = false;
context.imageSmoothingEnabled = false;