/*

If you run this app with the attached PNG image ("test.png") in
the same directory you'll see that the lightbulb image's background
is white - not transparent. However viewing the same image with
Microsoft's tools shows that the image has a transparent background.
As well it should, since it was saved that way using IrFanView 3.98,
a freeware image editor.

*/

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

public class Test {
   JFrame mainFrame = null;

   void initialize(String[] ignore) {
       Icon icon = new ImageIcon("test.png");
       mainFrame = new JFrame("Image should have transparent background");
       Container cp = mainFrame.getContentPane();
       cp.setBackground(Color.green);
       mainFrame.add(new JLabel(icon));
   }

   void show() {
       mainFrame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
       mainFrame.pack();
       mainFrame.setVisible(true);
   }

   public static void main(final String[] args) throws Exception {
       Runnable doCreateAndShowGUI = new Runnable() {
           public void run() {
               try {
                   Test app = new Test();
                   app.initialize(args);
                   app.show();
               }
               catch (Exception e) {
                   // TBD log an error
               }
           }
       };
       SwingUtilities.invokeLater(doCreateAndShowGUI);
   }
}