Robot screen capture returns black image

[Jaeela]

I am using a program called PsExec(PsExec) to execute a jar file remotely. The program takes a BufferedImage of the screen, converts it to an Image that is Serializable, and sends it through sockets to a server program. the server program then displays it onto a JPanel, and the image is black. This only happens when i execute the jar file remotely. Even when I execute a program that saves an image to a file remotely, the image turns out black.

troublesome code:

			Robot r = new Robot();
			while(true) {
				BufferedImage bi = r.createScreenCapture(new Rectangle(Toolkit.getDefaultToolkit().getScreenSize()));
			      double scale = 0.75;
			      int w = (int) (bi.getWidth() * scale);
			      int h = (int) (bi.getHeight() * scale); 
			      BufferedImage outImage = new BufferedImage(w, h, BufferedImage.TYPE_INT_RGB);                
			      AffineTransform trans = new AffineTransform();
			      trans.scale(scale, scale);
			      Graphics2D g = (Graphics2D) outImage.createGraphics();
			      g.drawImage(bi, trans, null);
			      g.dispose();
				image = new SerializableImage(outImage);
				Server.out.writeObject(image);

SerializableImage:

import java.awt.Component;
import java.awt.Graphics2D;
import java.awt.Image;
import java.awt.MediaTracker;
import java.awt.Toolkit;
import java.awt.image.BufferedImage;
import java.awt.image.ColorModel;
import java.awt.image.ImageObserver;
import java.awt.image.MemoryImageSource;
import java.awt.image.PixelGrabber;
import java.io.IOException;
import java.io.ObjectInputStream;
import java.io.ObjectOutputStream;
import java.io.Serializable;
/**
 * This module is free software. It may be copied, sold, and modified at will.
 * This module may not be copyrighted by any parties without the permission of the author.
 * @author Don Corley <don@donandann.com>
 *
 */
public class SerializableImage extends Object
    implements Serializable, ImageObserver {
    private static final long serialVersionUID = 1L;
    int width;
    int height;
    int[] pixels;
    /**
     * Creates an Image that can be serialized.
     */
    public SerializableImage() {
    }
    public SerializableImage(Image image) {
        this.setImage(image);
    }
    public void readObject(ObjectInputStream s) throws ClassNotFoundException,
            IOException {
        s.defaultReadObject();
        width = s.readInt();
        height = s.readInt();
        pixels = (int[]) (s.readObject());
    }
    public BufferedImage toBufferedImage(Image i) {
    	BufferedImage bi = new BufferedImage(i.getWidth(null), i.getHeight(null), BufferedImage.TYPE_INT_RGB);
    	Graphics2D g = bi.createGraphics();
    	g.drawImage(i, 0, 0, null);
    	return bi;
    }
    public void writeObject(ObjectOutputStream s) throws IOException {
        s.defaultWriteObject();
        s.writeInt(width);
        s.writeInt(height);
        s.writeObject(pixels);
    }
    public int getImageWidth() {
        return width;
    }
    public int getImageHeight() {
        return height;
    }
    public Image getImage() {
        Image image = null;
        if (pixels != null) {
            Toolkit tk = Toolkit.getDefaultToolkit();
            ColorModel cm = ColorModel.getRGBdefault();
            image = tk.createImage(new MemoryImageSource(width, height, cm, pixels, 0, width));
        }
        return image;
    }
    public void setImage(Image image) {
        
        loadImage(image);
        width = image.getWidth(this);
        height = image.getHeight(this);
        pixels = image != null ? new int[width * height] : null;
        if (image != null) {
            try {
                PixelGrabber pg = new PixelGrabber(image, 0, 0, width, height, pixels, 0, width);
                pg.grabPixels();
                if ((pg.getStatus() & ImageObserver.ABORT) != 0) {
                    throw new RuntimeException("failed to load image contents");
                }
            } catch (InterruptedException e) {
                throw new RuntimeException("image load interrupted");
            }
        }
    }
    
    static MediaTracker tracker = null;
    static int mediaTrackerID = 0;
    
    /**
     * Loads the image, returning only when the image is loaded.
     * Note: This USUSALLY is a bad idea (to hang this thread until the image loads),
     * but in this case, images are ONLY loaded here when they are initially set which
     * is when they are selected by the user.
     * @param image the image
     */
    protected void loadImage(Image image) {
        MediaTracker mTracker = getTracker();
        synchronized(mTracker) {
            int id = getNextID();
            mTracker.addImage(image, id);
        try {
                mTracker.waitForID(id, 0);
        } catch (InterruptedException e) {
        System.out.println("INTERRUPTED while loading Image");
        }
            //?int loadStatus = mTracker.statusID(id, false);
            mTracker.removeImage(image, id);
    }
    }
    /**
     * Returns an ID to use with the MediaTracker in loading an image.
     */
    private int getNextID() {
        synchronized(getTracker()) {
            return ++mediaTrackerID;
        }
    }
    /**
     * Returns the MediaTracker for the current AppContext, creating a new
     * MediaTracker if necessary.
     */
    private MediaTracker getTracker() {
        // Opt: Only synchronize if trackerObj comes back null?
        // If null, synchronize, re-check for null, and put new tracker
        synchronized(this) {
            if (tracker == null) {
                @SuppressWarnings("serial")
                Component comp = new Component() {};
                tracker = new MediaTracker(comp);
            }
        }
        return (MediaTracker) tracker;
    }
    @Override
    public boolean imageUpdate(Image img, int infoflags, int x, int y,
            int width, int height) {
        // Since I wait for an image to load, I know I have the image.
        return true;
    }
}

[mithun.raman]

HI jaleele,

I am also stuck at the same problem.
Have you found a solution ??
Thanks in advance,
Mithun