It uses Inflater from java.util.zip and I did not provide a hook to exchange it with another zlib implementation.
What's that all about custom zlib versions? Are there huge performance gains by using a Java based zlib (which I doubt)? The additional code size is an issue, I want to keep the library small.
hum zlib is native code in java and should be pretty fast, it seems to me to be a copy (used often in other project than java jre) of an existing librarie (probably "sun-java-boys" get afraid too to redo it from scratch
), the interresting thing would have be to get better control but also provide a full-cross platform png loader (not dependent on any external libraries)
NB: I just noticed that you only implement paletized PNG ? ( even if it would requiere few lines, this is the only one I did not take the time to implement as it was not yet really requiered for me, I have done some debug/improvments that I will try to post "a day ...")