public void show() {

        // create the GUI for viewing the image if needed
        if (frame == null) {
            frame = new JFrame();

            JMenuBar menuBar = new JMenuBar();
            JMenu menu = new JMenu("File");
            menuBar.add(menu);
            JMenuItem menuItem1 = new JMenuItem(" Save...   ");
            menuItem1.addActionListener(this);
            menuItem1.setAccelerator(KeyStroke.getKeyStroke(KeyEvent.VK_S,
                                     Toolkit.getDefaultToolkit().getMenuShortcutKeyMask()));
            menu.add(menuItem1);
            frame.setJMenuBar(menuBar);



            frame.setContentPane(getJLabel());
            // f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
            frame.setDefaultCloseOperation(JFrame.DISPOSE_ON_CLOSE);
            frame.setTitle(filename);
            frame.setResizable(false);
            frame.pack();
            frame.setVisible(true);
        }

        // draw
        frame.repaint();
    }