bmd = document.getElementById("canvas").bitmapData;

for (var i = 0; i<100; i++) {
	for (var j = 0; j<300; j++) {
		var d = Math.pow(i-50, 2) + Math.pow(j-150, 2);
		var r = Math.sin(Math.sqrt(d) * 10 * Math.PI/180);
		var color = 100 + 100 * r << 16;
		bmd.setPixel( i, j, color );
	}
}

bmd.copyChannel(bmd, 
	bmd.rect, 
	new Point(100, 0), 
	BitmapDataChannel.RED, 
	BitmapDataChannel.GREEN);
	
bmd.copyChannel(bmd, 
	bmd.rect, 
	new Point(200, 0), 
	BitmapDataChannel.RED, 
	BitmapDataChannel.BLUE);
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