PNG ImageIO decoder available

[Chris Nokleberg]

Hello Graphics2D hackers,

The following Jar includes a PNG decoding library, ImageIO service
provider classes, and the necessary META-INF/services bits such that
ImageIO should load it automatically if it is put into jre/lib/ext (or
whatever the Classpath equivalent is):
http://prdownloads.sourceforge.net/javapng/javapng-2.0-rc3-iio.jar?download

The full source distribution is available here:
http://prdownloads.sourceforge.net/javapng/javapng-2.0-rc3-src.jar?download

The license is the same as Classpath.

The PNG decoding part of the library is quite complete, but the ImageIO
plugin is very basic. For example it doesn't have any metadata support.
Dimitri Koussa is working on improving the plugin, including at least
basic write support.

Aside from the ImageIO package, only classes in JDK 1.2 are used. I don't
have a recent version of Classpath up and running yet, so I'm
not sure what the state of the ImageIO support is, but you could also add
Toolkit support by calling the com.sixlegs.png API directly. FWIW in the
current version this would also have slightly better performance than
going through ImageIO.

I'd appreciate any feedback/patches/etc.

Chris