If you want to load/process/display images I suggest you use an image processing framework. Using Marvin, for instance, you can do that easily with just a few lines of source code.
Source code:
public class Example extends JFrame{
MarvinImagePlugin prewitt = MarvinPluginLoader.loadImagePlugin("org.marvinproject.image.edge.prewitt");
MarvinImagePlugin errorDiffusion = MarvinPluginLoader.loadImagePlugin("org.marvinproject.image.halftone.errorDiffusion");
MarvinImagePlugin emboss = MarvinPluginLoader.loadImagePlugin("org.marvinproject.image.color.emboss");
public Example(){
super("Example");
// Layout
setLayout(new GridLayout(2,2));
// Load images
MarvinImage img1 = MarvinImageIO.loadImage("./res/car.jpg");
MarvinImage img2 = new MarvinImage(img1.getWidth(), img1.getHeight());
MarvinImage img3 = new MarvinImage(img1.getWidth(), img1.getHeight());
MarvinImage img4 = new MarvinImage(img1.getWidth(), img1.getHeight());
// Image Processing plug-ins
errorDiffusion.process(img1, img2);
prewitt.process(img1, img3);
emboss.process(img1, img4);
// Set panels
addPanel(img1);
addPanel(img2);
addPanel(img3);
addPanel(img4);
setSize(560,380);
setVisible(true);
}
public void addPanel(MarvinImage image){
MarvinImagePanel imagePanel = new MarvinImagePanel();
imagePanel.setImage(image);
add(imagePanel);
}
public static void main(String[] args) {
new Example().setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
}
}
Output: