Uncompress ATF v6 file to png.
But it just can export ETC1 pkm file now.
###Format support:
- ATFRAWCOMPRESSEDALPHA
###Usage:
$ make
$ ./atf2png path_to.atf # export output.pkm and output_alpha.pkm
Merge two png files into one.
###Usage:
mergetool -i inputdir -o outputdir