[Hauts]

import flash.display.BitmapData;
import flash.display.Bitmap;
import flash.events.MouseEvent;
import flash.display.Sprite;
import flash.geom.Rectangle;
import flash.geom.Point;
 
var bd:BitmapData = new BitmapData(image.width,image.height,true,0x00000000);
bd.draw(image);
 
var bitmap:Bitmap = new Bitmap(bd);
var bitmapContainer:Sprite = new Sprite();
bitmapContainer.addChild(bitmap);
addChild(bitmapContainer);
var alphaBitmapData:BitmapData = new BitmapData(20,20,true,0xCC000000);
bitmapContainer.addEventListener(MouseEvent.MOUSE_MOVE, mouseMoveHandler);
 
function mouseMoveHandler(e:MouseEvent):void {
	var p:Point = new Point(bitmapContainer.mouseX - 5,bitmapContainer.mouseY - 5);
	var rect:Rectangle = new Rectangle(p.x,p.y,10,10);
	bd.copyPixels(bd, rect, p, alphaBitmapData);
}

Так?