2017.01.10 14:29 "Re: [Tiff] jbig2 and licence", by Bob Friesenhahn
if I'm not mistaken, tiff can depend on jbig2. Afaik, libtiff's configure.ac searches for jbig-kit, which is GPL. But libtiff is licensed under a BSD-like licence, which means that if I enable jbig2 support, libtiff becomes a GPL library, right?
There is some confusion since JBIG-KIT does not implement JBIG v2 (it implements JBIG v1) and source code does not "become GPL" due to linking with GPL code. However, you are correct that binaries linked with JBIG-KIT must offer/distribute all source code (other than for system libraries) for the whole library/program according to the terms of GPLv2.
If you are not willing to provide the source code for your using application then don't link libtiff with JBIG-KIT.
For perhaps historical reasons (patents which I believe have all expired now) I have noticed that Linux distributions derived from Debian Linux do not offer JBIG-KIT.
GraphicsMagick Maintainer, http://www.GraphicsMagick.org/