libiptcdata is a library for parsing, editing, and saving IPTC data.

libiptcdata is a library for manipulating the International Press
Telecommunications Council (IPTC) metadata stored within multimedia
files such as images. This metadata can include captions and keywords,
often used by popular photo management applications. The library
provides routines for parsing, viewing, modifying, and saving this
metadata. The libiptcdata package also includes a command line utility,
iptc, for editing IPTC data in JPEG files. The library implements the
IPTC Information Interchange Model according to its specification.