code: function (idx) {
  
  		var r = this.getRed(idx),
  			g = this.getGreen(idx),
  			b = this.getBlue(idx),
  			y,
  			i,
  			q;
  
  		y = this.getLumaAtIndex(idx);
  		i = Math.floor((0.595716 * r) - (0.274453 * g) - (0.321263 * b));
  		q = Math.floor((0.211456 * r) - (0.522591 * g) + (0.311135 * b));
  
  		y = y < 0 ? 0 : (y > 255 ? 255 : y);
  		i = i < 0 ? 0 : (i > 255 ? 255 : i);
  		q = q < 0 ? 0 : (q > 255 ? 255 : q);
  
  		return {y: y, i: i, q: q};
  	}
docs: Gets the YIQ-value of a pixel at a specific index
  The values for RGB correspond afterwards to YIQ respectively.
  
  @method getYIQAtIndex
  @param {int} idx Index of pixel
  @return {object} YIQ-value