Opera用

offset:

// コード
filter: function(flt, offset){
	if(!offset) offset = 0;

	var ip = new ImageProcessing(this.canvas.cloneNode(false));
	var gContext = ip.canvas.getContext("opera-2dgame");

	var n = parseInt(flt.length / 2);
	var width  = this.canvas.width - n;
	var height = this.canvas.height - n;
	var length = flt.length;

	var c = new ImageProcessing.Color(offset, offset, offset);
	var p = null;

	gContext.lockCanvasUpdates(true);

	for(var x = n; x < width; x++){
		for(var y = n; y < height; y++){

			for(var fx = 0; fx < length; fx++){
				for(var fy = 0; fy < length; fy++){
					p = this.getPixel(x + fx - n, y + fy - n);
					c.r += p.r * flt[fy][fx];
					c.g += p.g * flt[fy][fx];
					c.b += p.b * flt[fy][fx];
				}
			}

			gContext.setPixel(x, y, c);

			c = new ImageProcessing.Color(offset, offset, offset)
		}
	}

	gContext.lockCanvasUpdates(false);
	gContext.updateCanvas();

	return ip;
}