Obraz w tle przycisków

import java.awt.*;
import java.awt.event.*;
import javax.swing.*;

public class Start
{
	public static void main(String[] args)
	{
		MenuRamka mr = new MenuRamka();
		mr.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
		mr.show();
	}
}

class MenuRamka extends JFrame
{
	public MenuRamka()
	{
		Toolkit tk = Toolkit.getDefaultToolkit();
		Dimension rozEkr = tk.getScreenSize();
		int szerEkr = rozEkr.width;
		int wysEkr = rozEkr.height;
		
		setSize(szerEkr, wysEkr);
		setLocation(0, 0);
		
		MenuPanel mp = new MenuPanel();
		MenuTlo mt = new MenuTlo();
		Container Menu = getContentPane();
		Menu.add(mt);
		Menu.add(mp);
		
		int rozdEkr = szerEkr / wysEkr;
		if (rozdEkr == 16 / 9)
		{
			rozdEkrWynik = 9;
		}
		else if (rozdEkr == 16 / 10)
		{
			rozdEkrWynik = 10;
		}
		else
		{
			rozdEkrWynik = 4;
		}
	}
	public static int rozdEkrWynik;
}

class MenuTlo extends JLabel
{
	public void paintComponent(Graphics g)
	{
		super.paintComponent(g);
		
		Toolkit tk = Toolkit.getDefaultToolkit();
		
		if (MenuRamka.rozdEkrWynik == 9)
		{
			String MenuTloSciezka = "images/backgrounds/16_9.gif";
			Image MenuTlo = tk.getImage(MenuTloSciezka);
			g.drawImage(MenuTlo, 0, 0, null);
		}
		else if(MenuRamka.rozdEkrWynik == 10)
		{
			String MenuTloSciezka = "images/backgrounds/16_10.gif";
			Image MenuTlo = tk.getImage(MenuTloSciezka);
			g.drawImage(MenuTlo, 0, 0, null);
		}
		else if(MenuRamka.rozdEkrWynik == 4)
		{
			String MenuTloSciezka = "images/backgrounds/4_3.gif";
			Image MenuTlo = tk.getImage(MenuTloSciezka);
			g.drawImage(MenuTlo, 0, 0, null);
		}
	}
}

class MenuPanel extends JPanel
{	
	public MenuPanel()
	{
		JButton test = new JButton("Test");
		add(test);
	}
} 

public class Tlo extends JFrame implements ActionListener
{
    public static void main(String[] args)
    {
        new Tlo();
    }
    //------------------------
    public Tlo()
    {
        setLayout(null);
        setPreferredSize(new Dimension(750,406));

        JButton b=new JButton("Abrakadabra");
        b.setBounds(10,10,120,25);
        b.addActionListener(this);
        add(b);

        b=new JButton("Hokus-pokus");
        b.setBounds(10,110,120,25);
        add(b);

        JLabel bg=new JLabel(new ImageIcon("images/ayers.jpeg"));
        bg.setOpaque(true);
        bg.setBounds(0,0,750,406);
        add(bg);

        setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        pack();
        setLocationRelativeTo(null);
        setVisible(true);
    }
    ...
}