[incoob]

попробуйте в bitmapData срисовать со smoothing

var image:Bitmap = loader.content as Bitmap;
var bd:BitmapData = new BitmapData(image.bitmapData.width, image.bitmapData.height);
bd.draw(image, null, null, null, null, true);
image = new BitmapData(bd, "auto", true);