I did not write this code. I just got it from the sources.jar and posted it here because I needed it and figured others might need it as well.
This is the last version of OpenViewerFX that included the image processing classes (notably the PNG Quantizer) that are now part of JDeli
http://mvnrepository.com/artifact/org.jpedal/OpenViewerFX/6.6.14
https://search.maven.org/remotecontent?filepath=org/jpedal/OpenViewerFX/6.6.14/OpenViewerFX-6.6.14.pom https://search.maven.org/remotecontent?filepath=org/jpedal/OpenViewerFX/6.6.14/OpenViewerFX-6.6.14.jar https://search.maven.org/remotecontent?filepath=org/jpedal/OpenViewerFX/6.6.14/OpenViewerFX-6.6.14-javadoc.jar https://search.maven.org/remotecontent?filepath=org/jpedal/OpenViewerFX/6.6.14/OpenViewerFX-6.6.14-sources.jar