If you want your JSlider at the bottom try this:
frame.add(slider, BorderLayout.SOUTH);
at your code I think it is enough if you add to
add(slider1);
this:
add(slider1, BorderLayout.SOUTH);
EDIT: To display a set of slider on a JFrame with your picture, add your picture at a JPanel and your slider to a JPanel. So it is easier to place it.
Than you could use:
JPanel panel = new JPanel(new GridLayout(1, 0, 1, 0);
panel.add(slider1);
panel.add(slider2);
...
add(panel, BorderLayout.SOUTH);
add(picturepanel, BorderLayout.CENTER);
If you need more precision use a grid Layout!