The JPEGImageEncoder.encode() method fails in the JPEGFlip demo piece on winNT4.0 & True Color (32 bit). PIII 500 Mz & Diamond Viper V770 (NVIDIA RIVA TNT2) video card. JPEGFlip looks okay on other bit depths on winNT and it looks okay on win98 on all bit depths.

To reproduce run the JPEGFlip piece in the Java2D demo on winNT 32 bit visual:

java -cp Java2Demo.jar demos.Images.JPEGFlip

Here's the exception that JPEGImageEncoder.encode() throws :

com.sun.image.codec.jpeg.ImageFormatException: 4 band JFIF files imply CMYK enco
ding.
Param block indicates alternate encoding.
        at sun.awt.image.codec.JPEGImageEncoderImpl.encode(JPEGImageEncoderImpl.
java:336)
        at sun.awt.image.codec.JPEGImageEncoderImpl.encode(JPEGImageEncoderImpl.
java:225)
        at demos.Images.JPEGFlip.drawDemo(JPEGFlip.java:107)
        at DemoSurface.paint(DemoSurface.java:303)
        at javax.swing.JComponent.paintChildren(JComponent.java:491)
        at javax.swing.JComponent.paint(JComponent.java:685)

This demo can also be obtained in stand-alone mode from the samples page :

http://java.sun.com/products/java-media/2D/samples/suite/Image/JPEGFlip.java