[hardwired]

I want that graph to pop up in another window though
Launch a JDialog and add the graphic component (JPanel) to it.
Somewhere in_or_called_from_your_event_code:

Code:

GraphicPanel graphicPanel = new GraphicPanel(image, data);
JDialog dialog = new JDialog(desired_args);
dialog.add(graphicPanel);
// configure dialog as desired
dialog.setVisible(true);

How do I draw that background image into the program ?

Code:

class GraphicPanel extends JPanel {
    BufferedImage bgImage;
    int[][] data;

    GraphicPanel(BufferedImage image, int[] data) {
        bgImage = image;
        this.data = data;
    }

    protected void paintComponent(Graphics g) {
        super.paintComponent(g);
        int x = 10;
        int y = 10;
        g.drawImage(bgImage, x, y, this);
        // draw your grid lines...
        // draw your data points/lines as desired...
    }
}