The libjpeg package contains cjpeg,
rdjpgcom, wrjpgcom and jpeg
cjpeg compresses image files to produce a JPEG/JFIF file on the standard
output. Currently supported input file formats are: PPM (PBMPLUS color
format), PGM (PBMPLUS gray-scale format), BMP, and Targa.
djpeg decompresses image files from JPEG/JFIF format to either PPM
(PBMPLUS color format), PGM (PBMPLUS gray-scale format), BMP, or Targa
jpegtran is used for lossless transformation of JPEG
rdjpgcom displays text comments from within a JPEG
wrjpgcom inserts text comments into a JPEG file.
These libraries are used by many programs for reading and writing
jpeg format files.