private void getMaskedBitmap() {

    Bitmap bgBitmap =  BitmapFactory.decodeResource(getResources(), R.drawable.background_drawable);
    ImageView bg = (ImageView) findViewById(R.id.bg);
    bg.setImageBitmap(bgBitmap);

    Bitmap.Config conf = Bitmap.Config.ARGB_8888;
    Bitmap emptyBitmap = Bitmap.createBitmap(bgBitmap.getWidth(), bgBitmap.getHeight(), conf);
    Canvas canvasBmp = new Canvas(bgBitmap);


    ImageView mImageView = (ImageView) findViewById(R.id.troll_face);

    Bitmap original = BitmapFactory.decodeResource(getResources(), R.drawable.random_drawable);

    Bitmap mask = BitmapFactory.decodeResource(getResources(), R.drawable.mask_drawable);

    original = Bitmap.createScaledBitmap(original, mask.getWidth(), mask.getHeight(), true);

    Bitmap result = Bitmap.createBitmap(mask.getWidth(), mask.getHeight(), Config.ARGB_8888);

    Canvas mCanvas = new Canvas(result);
    Paint paint = new Paint(Paint.ANTI_ALIAS_FLAG);
    paint.setXfermode(new PorterDuffXfermode(PorterDuff.Mode.DST_IN));
    mCanvas.drawBitmap(original, 0, 0, null);
    mCanvas.drawBitmap(mask, 0, 0, paint);
    paint.setXfermode(null);

    mImageView.setImageBitmap(result);
    //mImageView.setScaleType(ScaleType.FIT_XY);
    mImageView.setBackgroundResource(R.drawable.background_drawable);

    bg.setOnTouchListener(new MultiTouchListener());

    mImageView.invalidate();


}