在一个图上画图

Bitmap b=BitmapFactory.decodeResource(CON.getResources(),R.drawable.deltio); 
    Bitmap bmOverlay = Bitmap.createBitmap(b.getWidth(), b.getHeight(), b.getConfig()); 
canvas = new Canvas(bmOverlay); 
Paint paint = new Paint(); 
            paint.setColor(Color.RED); 
canvas.drawBitmap(b, new Matrix(), null); 
canvas.drawCircle(750, 14, 11, paint);