如何不显示图片底纹

[img]/upload/attachment/128265/70ffb492-263c-3852-a76e-7acb652fdacb.gif[/img]
我的代码如下，正规的游戏中图片是看不到底纹的，我想去掉，请哪位好心不吝赐教，谢谢！
import java.awt.event.*;
import java.awt.*;

public class Img extends Frame
{
static Image image;

public Img()
{
    super("在Frame中添加图片");
    image = Toolkit.getDefaultToolkit().getImage(Img.class.getClassLoader().getResource("images/5.jpg"));
}

public void paint(Graphics g) {
     g.drawImage(image, 50, 50, 150,150,null);
}

public static void main(String [] args)
{
    Img frame = new Img();
    frame.setSize(300, 300);
    frame.setBackground(Color.GREEN);
    frame.setVisible(true);

         try {
              Thread.sleep(100);
         } catch (InterruptedException e) {
         e.printStackTrace();
        }
         frame.repaint();               
}

}

换成png,或者gif.先用photoshopw处理一下,保存的时候注意设置底色透明