Clear a transparent BufferedImage as fast as possible

Question

I have a transparent BufferedImage created with the following code(not relevant how it is created, I think):

            GraphicsEnvironment ge = GraphicsEnv         


        

Answer 1

Got it :) used clearRect instead of fill with a transparent color.

            graphics = (Graphics2D) offlineBuffer.getGraphics();
            graphics.setBackground(new Color(255, 255, 255, 0));
            Rectangle screen = transformationContext.getScreen();
            graphics.clearRect(0,0, (int)screen.getWidth(), (int)screen.getHeight());