Various patches to programs that handle Jef Poskanzer's PGM/PPM format used by the pbmplus tools, to extend the raw binary format to handle little endian 16 bit words when the maxval is greater than 255.
These were written initially to make practical use of the IJG JPEG code, and later became useful in the dicom3tools package.
There is a patch here for older versions of Bradley's xv packages but he folded it into the more recent distributions, so there is no need to use it.
The JPEG patch of course only allows one to use 12 bits as there is no 16 bit DCT process.