Alpha channel deteriorates on scaling image

Question

Using Flash CS4. I have some images with transparent backgrounds that I'm putting into Flash. Placed in Flash at original size, transparency looks great. However, when I scale the images to any different size, the edges of the alpha channel get real rough, not smooth and aligned to object. I've experimented with png, targa, gif, but all seem to have this problem. Is this some issue with Flash? I don't remember seeing this problem in say Powerpoint.
Note: I need the flexibility to change the size of the images, not produce an "exact size" original everytime I need a different size.
thanks,
Dennis

Answer 1

Min required version of flash player for my application is 9..
I think I figured it out, Here is my solution:
private function completeHandler(evt:Event):void
   var originalWidth:int=loaderG.content.width;
   var originalHeight:int=loaderG.content.height;
   var scale:Number = 0.5;
   var matrix:Matrix = new Matrix();
   matrix.scale(scale, scale);
   myBitmapDataObj=new BitmapData(originalWidth, originalHeight, true, 0xFFFFFF);
   myBitmapDataObj.draw(loaderG.content, null, null, null, null, true);
   var copyBitmapData:BitmapData= new BitmapData(originalWidth* scale, originalHeight* scale, true, 0x000000);
   copyBitmapData.draw(myBitmapDataObj, matrix, null, null, null, true);
   var myBitmapG:Bitmap=new Bitmap(copyBitmapData,PixelSnapping.AUTO,true);
   addChild(myBitmapG);
I also try blur filter on my bitmap:
var blur:BlurFilter = new BlurFilter();
   blur.blurX = 1.4;
   blur.blurY = 1.4;
   blur.quality = BitmapFilterQuality.HIGH;
   myBitmapG.filters = [blur];
Or is there better solution?