How can I make this JButton visible? When I have progressive scan background JWindow()?

It’s not clear how your video source works, but it appears to be incompatible with Swing due to Mixing Heavyweight and Lightweight Components. Although awt components aren’t transparent, you can always draw your own translucent text on the Frame and do manual hit testing, as suggested below. You might also check to see if your video source API supports Double Buffering and Page Flipping.

import java.awt.Color;
import java.awt.AlphaComposite;
import java.awt.Font;
import java.awt.FontMetrics;
import java.awt.Frame;
import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.Insets;
import java.awt.Rectangle;
import java.awt.event.MouseAdapter;
import java.awt.event.MouseEvent;
import java.awt.event.WindowAdapter;
import java.awt.event.WindowEvent;
import java.awt.geom.Rectangle2D;

/** @see http://stackoverflow.com/questions/6725618 */
public class AlphaFrame extends Frame {

    private static final Font font = new Font("Dialog", Font.BOLD, 24);
    private float alpha = 1f;
    private Rectangle rect = new Rectangle();

    public static void main(String[] args) {
        AlphaFrame af = new AlphaFrame();
        af.setTitle("Translucent Button");
        af.setAlpha(0.5f);
        af.setForeground(Color.green);
        af.setBackground(Color.black);
        af.setVisible(true);
    }

    public AlphaFrame() {
        this.setSize(320, 240);
        this.setLocationRelativeTo(null);
        this.setBackground(Color.white);
        this.addWindowListener(new WindowAdapter() {

            @Override
            public void windowClosing(WindowEvent e) {
                System.exit(0);
            }
        });
        this.addMouseListener(new MouseAdapter() {

            @Override
            public void mousePressed(MouseEvent e) {
                if (rect.contains(e.getPoint())) {
                    System.out.println("Pressed.");
                }
            }
        });
        repaint();
    }

    @Override
    public void paint(Graphics g) {
        super.paint(g);
        Graphics2D g2 = (Graphics2D) g;
        g2.setComposite(AlphaComposite.getInstance(
            AlphaComposite.SRC_OVER, alpha));
        g2.setColor(getForeground());
        g2.setFont(font);
        FontMetrics fm = g2.getFontMetrics();
        String s = getTitle();
        Insets i = getInsets();
        int dx = i.left + 10;
        int dy = i.top + fm.getHeight() + 10;
        Rectangle2D bounds = fm.getStringBounds(s, g);
        rect.x = dx + (int) bounds.getX() - 1;
        rect.y = dy + (int) bounds.getY() - 1;
        rect.width = (int) bounds.getWidth() + 1;
        rect.height = (int) bounds.getHeight() + 1;
        System.out.println(i + " \n" + bounds + "\n" + rect);
        g2.drawRect(rect.x, rect.y, rect.width, rect.height);
        g2.drawString(s, dx, dy);
    }

    public float getAlpha() {
        return alpha;
    }

    public void setAlpha(float alpha) {
        this.alpha = alpha;
    }
}