XP : extended precision
The libjpeg repository is a submodule of this repository (jpegxp) 3 times (see .gitmodules), with modifications to each submodule in a branch to support building a single JPEG codec capable of
- lossy 8-bit encode and decode lossy8
- lossy 12-bit encode and decode lossy12
- lossless decode (NOTE: no encode support) lossless
libjpeg https://libjpeg.sourceforge.net is written and distributed by the Independent JPEG Group (IJG) https://www.ijg.org
lossless decode support was derived from a patch provided by Ken Murchison https://en.wikipedia.org/wiki/Lossless_JPEG#cite_note-1
IJG license see LEGAL ISSUES in README