A DESCRIPTION OF THE REQUEST :
Image loading using Toolkit.getImage is 30-80% slower in Linux Java (1.5.0_05) than in Windows Java for large images, even if windows java is running in wine (windows emulator) in Linux (!!!). Both JPEG and PNG loading are slower.

JUSTIFICATION :
Waiting is always painful, especially in case of a slideshow program. Although JPEG reading is much faster in java 1.5 than in 1.4, it is still slow compared to windows java.

EXPECTED VERSUS ACTUAL BEHAVIOR :
EXPECTED -
There should be no speed difference. Linux java should use the same, faster JPEG and PNG readers as windows java.
ACTUAL -
Test results:
- GetImageTest with empty 15000x1000 JPEGs generated using imageio:
  12.19s P4 2.4GHz, SuSE Linux 10 RC1, Java 1.5.0_05-linux
   6.85s P4 2.4GHz, wine20050725/SuSE Linux 10 RC1, Java 1.5.0_05-win
  (first column is the runtime in seconds)
- GetImageTest with empty 15000x1000 PNGs generated using imageio:
  9.514s P4 2.4GHz, SuSE Linux 10 RC1, Java 1.5.0_05-linux
  7.266s P4 2.4GHz, wine20050725/SuSE Linux 10 RC1, Java 1.5.0_05-win
- loading some digital photos (large panorama images, JPEG) with SlideProject, a java slideshow program:
  31.2s P4 3.0GHz, SuSE Linux 9.1, Java 1.5.0_05-linux
  19.9s P4 3.0GHz, Windows XP, Java 1.5.0_05-win
  40.2s P4 2.4GHz, SuSE Linux 10 RC1, Java 1.5.0_05-linux
  29.8s P4 2.4GHz, wine20050725/SuSE Linux 10 RC1, Java 1.5.0_05-win

---------- BEGIN SOURCE ----------
CreateImages.java - program for creating the large test JPEGs:

import java.awt.image.BufferedImage;
import java.util.Iterator;
import java.io.*;
import java.nio.MappedByteBuffer;
import java.nio.channels.FileChannel;
import javax.imageio.*;
import javax.imageio.stream.ImageOutputStream;
public class CreateImages {
    public static void main(String[] args) throws Exception {
        // create jpg files by default or png if it is specified in first arg
        String fmt = args.length != 0? args[0] : "jpg";
        // create empty 15000x1000 image file b0.jpg or b0.png
        int[] pixels = new int[15000];
        BufferedImage im = new BufferedImage(15000, 1000,
                                             BufferedImage.TYPE_INT_RGB);
        Iterator it = ImageIO.getImageWritersByFormatName(fmt);
        ImageWriter wr = (ImageWriter)it.next();
        ImageOutputStream ios = ImageIO.createImageOutputStream(
                new File("b0."+fmt));
        wr.setOutput(ios);
        wr.write(null, new IIOImage(im, null, null), null);
        ios.flush();
        wr.dispose();
        ios.close();
        // create b1.jpg, ..., b9.jpg files by copying b0.jpg
        for(int i = 1; i < 10; ++i) {
            FileChannel in = new FileInputStream("b0."+fmt).getChannel();
            FileChannel out = new FileOutputStream("b"+i+"."+fmt).getChannel();
            long size = in.size();
            MappedByteBuffer buf = in.map(FileChannel.MapMode.READ_ONLY, 0, size);
            out.write(buf);
            in.close();
            out.close();
        }
    }
}

GetImageTest.java - the test program:

import java.awt.*;
import java.io.File;
import javax.swing.*;
public class GetImageTest extends JFrame {
    static final String[] DEFAULT_FILENAMES = new String[] {
        "b0.jpg", "b1.jpg", "b2.jpg", "b3.jpg", "b4.jpg",
        "b5.jpg", "b6.jpg", "b7.jpg", "b8.jpg", "b9.jpg"};
    JTextArea txt;
    GetImageTest(int nrows) {
        super("GetImageTest");
        setDefaultCloseOperation(WindowConstants.EXIT_ON_CLOSE);
        getContentPane().setLayout(new GridLayout());
        getContentPane().add(txt = new JTextArea(nrows, 80));
        txt.setFont(new Font("Monospaced", Font.PLAIN, 12));
        pack();
    }
    int getImage(String fname) throws InterruptedException {
        Thread.sleep(500); // 0.5s rest before start
        long t0 = System.currentTimeMillis();
        Image im = getToolkit().getImage(fname); // load image
        MediaTracker mt = new MediaTracker(this);
        mt.addImage(im, 0);
        mt.waitForAll();
        int t = (int)(System.currentTimeMillis() - t0); // milliseconds elapsed
        txt.append(String.format("%.3f %3.1fM %4.1fMpix %5dx%-4d %s\n",
                   0.001*t, (new File(fname).length())/1048576.0,
                   1e-6*im.getWidth(null)*im.getHeight(null),
                   im.getWidth(null), im.getHeight(null), fname));
        return t;
    }
    public static void main(String[] args) throws Exception {
        String[] fnames = args.length != 0? args : DEFAULT_FILENAMES;
        GetImageTest w = new GetImageTest(fnames.length + 2);
        w.setVisible(true);
        int tot = 0; // total time elapsed in milliseconds
        for(int i = 0; i < fnames.length; ++i) {
            int t = w.getImage(fnames[i]);
            tot += t;
        }
        // print total time elapsed in seconds
        w.txt.append(String.format("%.3f", 0.001*tot));
    }
}
---------- END SOURCE ----------

CUSTOMER SUBMITTED WORKAROUND :
Buying an 80% faster computer or trying to use the windows JVM with wine instead of the native linux JVM.