Bleach.java

import javax.swing.*;
import java.awt.*;
import java.awt.event.*;
import java.awt.image.FilteredImageSource;

/**
 * 
Initially displays an unbleached image.  Subsequent mouse
 * clicks in the canvas containing the image toggle between
 * a bleached version of the image and an unbleached version.
 *
 */

public class Bleach  {
	Image im;
	Image bleached;

	Bleach()
	{
		JFrame frame = new JFrame("Bleached Image");
		JPanel panel = new DrawPanel();
		Dimension d;

		/*
		// use AWT to get the image
		im = Toolkit.getDefaultToolkit().getImage("saint.gif");
		waitForImage(panel, im);
		d = new Dimension(im.getWidth(panel),im.getHeight(panel) );
		*/

		// use Swing to get the image
		ImageIcon icon = new ImageIcon("saint.gif");
		im = icon.getImage();
		d = new Dimension(icon.getIconWidth(),icon.getIconHeight() );

		panel.setPreferredSize(d);

		int bp = 50;

		FilteredImageSource source = 
			new FilteredImageSource(im.getSource(), new BleachImageFilter(bp));

		bleached = panel.createImage(source);
		waitForImage(panel, bleached);

		Container c = frame.getContentPane();
		c.add( new JLabel("Click image to toggle bleaching",JLabel.CENTER), BorderLayout.NORTH);
		c.add(panel,BorderLayout.CENTER);

		frame.pack();
		frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
		frame.show();
	}

	public static void waitForImage(JComponent component, Image im) {
		MediaTracker tracker = new MediaTracker(component);
		try {
			tracker.addImage(im, 0);
			tracker.waitForID(0);
		}
		catch(InterruptedException e) { System.out.println(e.toString()); }
	}

	class DrawPanel extends JPanel {
		boolean showBleached = false;

		DrawPanel()
		{
			addMouseListener(new myMouse() );
		}

		public class myMouse extends MouseAdapter {
			public void mouseClicked(MouseEvent e)
			{
				showBleached = !showBleached;
				repaint();
			}
		}

		public void paintComponent(Graphics g)
		{
			g.drawImage((showBleached? bleached: im),0,0,this);
		}
	}

	public static void main(String args[])
	{
		new Bleach();
	}
}

BleachImageFilter.java

import java.awt.image.*;

/**
 * 
A derivation of RGBImageFilter that bleaches an image.
 *
 * 
Extent of the bleaching effect is controlled by the only 
 * constructor argument: an integer representing the percentage 
 * of bleaching.  The percentage of bleaching may also be 
 * controlled after instantiation by invoking the 
 * void percent(int) method.
 *
 * @version 1.0, Apr 1 1996
 * @author  David Geary
 * @see     RGBImageFilter
 */
public class BleachImageFilter extends RGBImageFilter {
    private int percent;

    public BleachImageFilter(int percent) {
        this.percent = percent;
        canFilterIndexColorModel = true;
    }
    public int  percent()            { return percent;    }
    public void percent(int percent) { percent = percent; }

    public int filterRGB(int x, int y, int rgb) {
        DirectColorModel cm = 
            (DirectColorModel)ColorModel.getRGBdefault();

        int    alpha = cm.getAlpha(rgb);
        int    red   = cm.getRed  (rgb);
        int    green = cm.getGreen(rgb);
        int    blue  = cm.getBlue (rgb);
        double percentMultiplier = (double)percent/100;

        red   = Math.min((int)
                (red + (red * percentMultiplier)), 255);
        green = Math.min((int)
                (green + (green * percentMultiplier)), 255);
        blue  = Math.min((int)
                (blue  + (blue  * percentMultiplier)), 255);

        alpha = alpha << 24;
        red   = red   << 16;
        green = green << 8;

        return alpha | red | green | blue;
    }
}

Maintained by John Loomis, last updated 15 June 2000