Colocando imagem usando "final"

Gostaria de colocar uma imagem que está no meu projeto, porem estou com dificuldade de colocá-lo como final:

package Pacote;

import java.awt.*;   
import java.awt.event.*;   
import javax.swing.*;
import javax.swing.GroupLayout.Alignment;
import javax.swing.LayoutStyle.ComponentPlacement;   
  
public class Tela extends JFrame implements ActionListener{   

	     Container c = getContentPane();
         JPanel login = new JPanel();
         JLabel ll, ls;
         JTextField tl;
         JPasswordField ts;
         JButton ok;
         private JPanel panel;
         
    public Tela(){   
    	super  ("Clinica Odontológica - IDENTIFIQUE-SE");
    	getContentPane().setBackground(new Color(240, 240, 240));
		setIconImage(Toolkit.getDefaultToolkit().getImage(TelaLogin.class.getResource("/Clinica/imagens/logomarca.png")));
		 setSize(981, 623);
		 setVisible(true);
		 setResizable(false);  
		 setLocation(10, 30); 
		 setDefaultCloseOperation(EXIT_ON_CLOSE);
         
        c.setLayout(new BorderLayout());   
          
        final ImageIcon bg = new ImageIcon(TelaLogin.class.getResource("/Clinica/imagens/bg_telalogin.png"));   
      
        panel = new JPanel();
        getContentPane().add(panel, BorderLayout.CENTER);
         panel.setLayout(new BorderLayout(0, 0));
           login = new JPanel(){
        	
			Image image = bg.getImage();   
              
              {   
                  setOpaque(false);   
              }   
  
              public void paint(Graphics g) {   
                  g.drawImage(image, 0, 0, this);   
                  super.paint(g);   
              }  
        }; 
           panel.add(login);
            
           // login.setBorder(BorderFactory.createTitledBorder("LOGIN"));
            login.add(ll = new JLabel("Login: "));
            login.add(tl = new JTextField());
            tl.setColumns(10);
            login.add(ls = new JLabel("\nSenha: "));
            ls.setHorizontalAlignment(SwingConstants.TRAILING);
            login.add(ts = new JPasswordField());
            login.add(ok = new JButton("ok"));
            GroupLayout gl_login = new GroupLayout(login);
            gl_login.setHorizontalGroup(
            	gl_login.createParallelGroup(Alignment.LEADING)
            		.addGroup(gl_login.createSequentialGroup()
            			.addGap(284)
            			.addComponent(ll)
            			.addPreferredGap(ComponentPlacement.RELATED)
            			.addComponent(tl, GroupLayout.PREFERRED_SIZE, GroupLayout.DEFAULT_SIZE, GroupLayout.PREFERRED_SIZE)
            			.addGap(76)
            			.addComponent(ls)
            			.addPreferredGap(ComponentPlacement.RELATED)
            			.addComponent(ts, GroupLayout.PREFERRED_SIZE, GroupLayout.DEFAULT_SIZE, GroupLayout.PREFERRED_SIZE)
            			.addPreferredGap(ComponentPlacement.RELATED)
            			.addComponent(ok)
            			.addContainerGap(317, Short.MAX_VALUE))
            );
            gl_login.setVerticalGroup(
            	gl_login.createParallelGroup(Alignment.TRAILING)
            		.addGroup(gl_login.createSequentialGroup()
            			.addContainerGap(343, Short.MAX_VALUE)
            			.addGroup(gl_login.createParallelGroup(Alignment.BASELINE)
            				.addComponent(tl, GroupLayout.PREFERRED_SIZE, GroupLayout.DEFAULT_SIZE, GroupLayout.PREFERRED_SIZE)
            				.addComponent(ll)
            				.addComponent(ls)
            				.addComponent(ts, GroupLayout.PREFERRED_SIZE, GroupLayout.DEFAULT_SIZE, GroupLayout.PREFERRED_SIZE)
            				.addComponent(ok))
            			.addGap(229))
            );
            login.setLayout(gl_login);
          
          ts.setColumns(10);
          tl.setColumns(10);
   
    }   
       
    public void actionPerformed(ActionEvent e) {
		  
	  }
	
	public static void main(String[] args) {
	
	        JFrame Janela= new Tela();
	       Janela.show();
	       WindowListener x=new WindowAdapter(){
	           public void windowClosing(WindowEvent e){
	               System.exit(0);
	           }
	       };
	    Janela.addWindowListener(x);
		
	}

}