question: static void clearImage ( BufferedImage img ) { Graphics2D g2 = img . createGraphics ( ) ; g2 . setComposite ( AlphaComposite . Clear ) ; g2 . fillRect ( 0 , 0 , img . getWidth ( ) , img . getHeight ( ) ) ; g2 . dispose ( ) ; }
target:  Clear a transparent image to 100% transparent