Canvas multiply (IE)

multiply.js

// Also see https://github.com/Phrogz/context-blender

function multiply(R, G, B) {
  var imgData = ctx.getImageData(0, 0, canvas.width, canvas.height);
  var data = imgData.data;

  for (var i = 0; i < data.length; i += 4) {
    data[i    ] = R * data[i    ] / 255;
    data[i + 1] = G * data[i + 1] / 255;
    data[i + 2] = B * data[i + 2] / 255;
  }

  ctx.putImageData(imgData, 0, 0);
}