Hello
I recently compiled libpng using the following xcode project: https://github.com/IGRSoft/libpng-xcode-project

Attempting to load a .png file always returns NULL, tried more than one file. Bmp loads fine through.
Also tested in both simulator and real device, no difference.

Ps: at first trying to build the app gave me an error:

Undefined symbols for architecture armv7:
"_png_init_filter_functions_neon", referenced from:

After a short google search I recompiled the library with this feature turned off. Could it be the reason?

Uh, yeah. That's why. You need the image addon initialized and with png support built in during compilation. <o.o>

Found the solution.

In xcode project settings -> build settings there is "compress png files" and "remove text metadata from png files" both must be set to NO.