python-imaging/Pillow — pull request #606 by wiredfool (2014-04-08 05:30:11+00:00)
Title: 16 bit PGM support. 

* Read and write support for 16 bit depth PGM images. Fixes #602.
* Should work with 32 bit pgm, should they actually exist. Even if they don't, I'd leave read support in.