public class ImageLoading extends JPanel {

    private static final long serialVersionUID = 1L;
    static Color displayedImage[][] = new Color[320][256];
    static BufferedImage image = null;
   
    @Override
    public void paintComponent(Graphics g) {
        super.paintComponent(g);

        // drawing the image to the screen
        for (int y = 0; y < 256; y++) {
            for (int x = 0; x < 320; x++) {
                g.setColor(displayedImage[x][y]);
                g.drawLine(x,y,x,y);
            }
        }
    }
   
    public static void main(String[] args) {
        // loading the image
        try {
            image = ImageIO.read(new File("csaj2.png"));
        } catch (IOException e) {
        }

        JFrame frame = new JFrame("ImageLoading");
        frame.setSize(350, 300);
        // making the app close when the app window gets closed
        frame.addWindowListener(new WindowAdapter() { public void windowClosing(WindowEvent e) { System.exit(0); }});
        frame.getContentPane().add(new ImageLoading());
        frame.setVisible(true);

        // copying the loaded image to the displayed image buffer
        for (int y = 0; y < 256; y++) {
            for (int x = 0; x < 320; x++)
                displayedImage[x][y] = new Color(image.getRGB(x, y));
        }
    }
}