There’s now a JHOVE PNG module on my GitHub site. The relevant new classes are
com.mcgath.jhove.module.PngModule and everything in the package
com.mcgath.jhove.module.png. I could have continued from Lauri’s code as I mentioned in my previous post, but I like a more factored approach, so I continued with my own code, which has a separate class for each chunk type. Take a look at the top-level file FORKNOTES for what I’ve been doing.
It does a pretty decent job of validating files and extracting metadata now, but some chunk types are still ignored, and there are some design decisions on the extracted metadata that I’m not sure about yet. Also, JHOVE modules usually have a lot of metadata about themselves, and that’s not complete yet. If anyone wants to play with it, keeping in mind that it’s not stable code yet, please do and submit issue reports for bugs and suggestions.