Manipulating ImageIcons

I have done a little Java programming before, but I'm more used to scripting languages such as shell scripts and perl.

I have an "ImageIcon" returned as a result of a class that I've been provided. I wish to be able to display the image icon on the screen, and be able click on areas of the icon by using the mouse and either turn those areas a specific colour such as red, or be able to read the rgb value of the location clicked.

Final issue is that if the image is larger than the viewing area, then I'd like to be able to scroll it. So far I have a JLabel(picLabel) inside a JScrollPane, which displays the image nicely, and enables me to scroll around the image:

----------8X-----------
        ImageIcon i = customClass.GetImage();
        picLabel.setIcon(i);
        picLabel.setText("");
       
        BufferedImage bi = new BufferedImage(i.getIconWidth(), i.getIconHeight(), BufferedImage.TYPE_INT_ARGB);
        Graphics2D g = bi.createGraphics();
        i.paintIcon(new JPanel(), g, 0,0);
----------8X-----------

How can I read individual pixels from the ImageIcon, and draw onto this icon, or is there a better set of classes to use for this. Ideas, examples and suggestions welcome. I've allocated 500pts, because I find my knowledge of classes and how to intereact with them is weak, but this might be fairly obvious to those with greater expertise in this area than myself.