question: public BufferedImage createCompatibleImage ( int width , int height ) { WritableRaster wr = raster . createCompatibleWritableRaster ( width , height ) ; return new BufferedImage ( model , wr , model . isAlphaPremultiplied ( ) , null ) ; }
target:  Returns a BufferedImage with channel layout and color model compatible with this graphics configuration.  This method has nothing to do with memory-mapping a device.  This BufferedImage has a layout and color model that is closest to this native device configuration and thus can be optimally blitted to this device.