Using imageio to convert .gif to .jpg gives bad image

Question

Hi,
I'm looking at the 1.4 javax.imageio API, and wrote a naive
program to convert images from one format to another.
It will read .gif, .jpg or .png and correctly write .gif and .png
images, but when I try to write a .jpg from a .gif or .png
the result is very black-looking - actually most of the colour
is there but changed to a very dark level and red switched to blue
for example. Presumably there is a reason that this doesn't work,
or is it a bug? I would've though an exception would be thrown
if the image types selected were incompatible.
Also, how does one specify the JPEG quality setting?
Thanks for any clues,
Ed
import javax.imageio.*;
import java.awt.*;
import java.io.*;
import java.awt.image.*;
public class ImageTest
public static void main(String[] argv)
try
File f1 = new File(argv[0]);
BufferedImage bi = ImageIO.read(f1);
System.out.println("Read "+f1+" OK.");
System.out.println("Image="+bi);
File f2 = new File(argv[1]);
String extn = f2.getName();
extn = extn.substring(extn.lastIndexOf('.')+1);
ImageIO.write(bi, extn, f2);
System.out.println("Wrote "+f2+" OK format="+extn);
catch (Exception ex)
ex.printStackTrace();

Answer 1

Interesting, the program works correctly on Windows 2000
and Solaris Sparc; The .jpg file creating problem only
occurs on my Solaris x86 machine.
Ed