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;
    }
}

import java.awt.event.*;
import java.awt.Color;
import java.awt.AlphaComposite;
import java.awt.Dimension;
import javax.swing.*;
import javax.swing.UIManager.LookAndFeelInfo;

public class ButtonTest {

    public static void main(String[] args) {
        SwingUtilities.invokeLater(new Runnable() {

            @Override
            public void run() {
                new ButtonTest().createAndShowGUI();
            }
        });
    }
    private JFrame frame;
    private SoftJButton softButton1;

    public void createAndShowGUI() {
        softButton1 = new SoftJButton("Transparent Button");
        softButton1.setPreferredSize(new Dimension(800, 600));
        frame = new JFrame();
        frame.add(softButton1);
        frame.setLocation(150, 150);
        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        frame.pack();
        frame.setVisible(true);
        Timer alphaChanger = new Timer(30, new ActionListener() {

            private float incrementer = -.03f;

            @Override
            public void actionPerformed(ActionEvent e) {
                float newAlpha = softButton1.getAlpha() + incrementer;
                if (newAlpha < 0) {
                    newAlpha = 0;
                    incrementer = -incrementer;
                } else if (newAlpha > 1f) {
                    newAlpha = 1f;
                    incrementer = -incrementer;
                }
                softButton1.setAlpha(newAlpha);
            }
        });
        alphaChanger.start();
        Timer uiChanger = new Timer(5500, new ActionListener() {

            private LookAndFeelInfo[] laf = UIManager.getInstalledLookAndFeels();
            private int index = 1;

            @Override
            public void actionPerformed(ActionEvent e) {
                try {
                    UIManager.setLookAndFeel(laf[index].getClassName());
                    SwingUtilities.updateComponentTreeUI(frame);
                } catch (Exception exc) {
                    exc.printStackTrace();
                }
                index = (index + 1) % laf.length;
            }
        });
        uiChanger.start();
    }

    public static class SoftJButton extends JButton {

        private static final JButton lafDeterminer = new JButton();
        private static final long serialVersionUID = 1L;
        private boolean rectangularLAF;
        private float alpha = 1f;

        public SoftJButton() {
            this(null, null);
        }

        public SoftJButton(String text) {
            this(text, null);
        }

        public SoftJButton(String text, Icon icon) {
            super(text, icon);

            setOpaque(false);
            setFocusPainted(false);
        }

        public float getAlpha() {
            return alpha;
        }

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

        @Override
        public void paintComponent(java.awt.Graphics g) {
            java.awt.Graphics2D g2 = (java.awt.Graphics2D) g;
            g2.setComposite(AlphaComposite.getInstance(AlphaComposite.SRC_OVER, alpha));
            if (rectangularLAF && isBackgroundSet()) {
                Color c = getBackground();
                g2.setColor(c);
                g.fillRect(0, 0, getWidth(), getHeight());
            }
            super.paintComponent(g2);
        }

        @Override
        public void updateUI() {
            super.updateUI();
            lafDeterminer.updateUI();
            rectangularLAF = lafDeterminer.isOpaque();
        }
    }
}