public void insertBitmap(final BufferedImage bitmap,final int x,final int y,final int xx,final int yy){
  insertBitmap(bitmap,x,y,bitmap.getRGB(xx,yy));
}

public void insertBitmap ( final BufferedImage bitmap , final int x , final int y , final int xx , final int yy ) { insertBitmap ( bitmap , x , y , bitmap . getRGB ( xx , yy ) ) ; }
inserts image where all pixels which have the same rgb value as the pixel at ( xx , yy ) are transparent
