FLASHAS实现马赛克效果 

import flash.display.BitmapData;
// 场景中摆个叫 img 的 mc 就 ok
var oldBmp:BitmapData = new BitmapData(img._width, img._height);
oldBmp.draw(img);
var newBmp:BitmapData = mosaic(oldBmp, 12);
var mc = createEmptyMovieClip("mc", 1);
mc.attachBitmap(newBmp, getNextHightestDepth());
mc._x = img._width;
function mosaic(bmp:BitmapData, stride:Number):BitmapData {
 var startTime = getTimer();
 
 var newBmp:BitmapData = new BitmapData(bmp.width, bmp.height);
 var w = bmp.width / stride + 1;
 var h = bmp.height / stride + 1;
 var edgeW = bmp.width % stride; // 边缘不足 stride 的部分
 var edgeH = bmp.height % stride;
 var centerW = (stride-1)/2; // 第一格的中心点
 var centerH = centerY; // 第一格永远是方的
 var tmpX, tmpY; // 循环中的真实像素位置， 前面 w, h 被除过了..
 var blockW, blockH; // 马赛克的格子
 
 var i = -1;
 while (++i < w) {
  tmpX = i * stride;
  if (i == w - 1){
   blockW = edgeW;
  } else {
   blockW = stride;
  }
  centerW = (blockW - 1) / 2;
  var j = -1;
  while (++j < h) {
   tmpY = j * stride;
   if (i == h - 1){
    blockH = edgeH;
   } else {
    blockH = stride;
   }
   centerH = (blockH - 1) / 2;
   var color = bmp.getPixel(tmpX + centerW, tmpY + centerH);
   var m = -1;
   while (++m < blockW) {
    var n = -1
    while (++n < blockH) {
     newBmp.setPixel(tmpX + m, tmpY + n,color);
    }
   }
  }
  
 }
 trace("Cost : "+(getTimer()-startTime));
 return newBmp;
}

以上代码请用FLASH8编译执行.