можно и битмапами

Код AS1/AS2:
import flash.display.BitmapData;
var mc_box:MovieClip = this.createEmptyMovieClip('mc_box', 1);
var bmp_img:BitmapData = BitmapData.loadBitmap('image.jpg');
var mc_img:MovieClip = mc_box.createEmptyMovieClip('mc_img', 1);
mc_img.attachBitmap(bmp_img, 0);
var bmp_mask:BitmapData = BitmapData.loadBitmap('mask.png');
var mc_mask:MovieClip = mc_box.createEmptyMovieClip('mc_mask', 2);
mc_mask.attachBitmap(bmp_mask, 0);
mc_mask.blendMode = 11;
mc_box.blendMode = 2;