Anaglyph canvas

anaglyph.js

renderLeft();
var canvasData1 = context.getImageData(0, 0, WIDTH, HEIGHT);

renderRight();
var canvasData2 = context.getImageData(0, 0, WIDTH, HEIGHT);

var
  dataRed = canvasData1.data,
  dataCyan = canvasData2.data,
  R, G, B;

for (var i = 0, il = dataRed.length; i < il; i+= 4) {
  R = i;
  G = i+1;
  B = i+2;
  dataRed[R] = 0.7 * (dataRed[G] || 235)  + 0.3 * (dataRed[B] || 230);
  dataRed[G] = dataCyan[G];
  dataRed[B] = dataCyan[B];
}

context.clearRect(0, 0, WIDTH, HEIGHT);
this.context.putImageData(canvasData1, 0, 0);