The jbig tools are derived from the JBIG-KIT package by Marcus Kuhn,
by Bryan Henderson on 2000.05.11.

The file ANNOUNCE in the 'libjbig' subdirectory is from that package and gives
details.

The Netpbm tools jbigtopbm and pbmtojbig were adapted from JBIG-KIT's
jbgtopbm and pbmtojbg.  The main difference is that the Netpbm
versions use the Netpbm libraries.

The code in subdirectory 'libjbig' is straight from the JBIG_KIT package and
generates essentially the same libjbig.a that one gets from that package.

The code is based on JBIG-KIT version 2.1, adapted to Netpbm by Bryan
Henderson in June 2014.

The reason Netpbm contains a copy of the library is convenience of users.  For
many people, the only reason to have a jbig library is to be able to convert
images to and from the format, which they do with Netpbm.  Requiring a Netpbm
user to find and install this esoteric library is impractical.