[ActionScript 3.0] AS3.0 将图像的Alpha通道转换为黑白图像(分离ARGB方式)

import flash.display.BitmapData;
import flash.display.Bitmap;

/**
 * 将图像的Alpha通道转换为黑白图像(分离ARGB方式)
 */
var bmpd:BitmapData = new ImagePNG();//绑定的png图片

var pixBmpd:BitmapData = new BitmapData(bmpd.width,bmpd.height,false);
for (var i:int=0; i< bmpd.height; i++)
{
    var s:String = "";
    for (var j:int=0; j<bmpd.width; j++)
    {
        var pixel:uint = bmpd.getPixel32(j,i);
        var obj:Object = splitARGB(pixel);
        var temp:String = obj.a == 0 ? "00":obj.a.toString(16);
        s +=  temp + " ";
        pixel = mixRGB(obj.a);
        pixBmpd.setPixel(j,i,pixel);
    }
    //trace(s);//字符画
}
var bmp:Bitmap = new Bitmap(pixBmpd);
this.addChild(bmp);

function splitARGB($argb:uint):Object
{
    return {a:$argb >> 24 & 0xFF,
    r:$argb >> 16 & 0xFF,
    g:$argb >> 8 & 0xFF,
    b:$argb & 0xFF};
}

function mixARGB($color:uint):uint
{
    return $color << 24 | $color << 16 | $color << 8 | $color;
}

function mixRGB($color:uint):uint
{
    return $color << 16 | $color << 8 | $color;
}