LibRaw is a library for reading RAW files obtained from digital photo cameras (CRW/CR2, NEF, RAF, DNG, and others). LibRaw is based on the source codes of the dcraw utility, though some of the drawbacks of dcraw have been eliminated. The users of the library are provided with an API to be used when writing their software programs.
libiptcdata is a C 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 Python bindings and a command-line utility, iptc, for viewing and editing IPTC data in JPEG files.
Mimas Toolkit is a C++ computer vision toolkit. It is easy to use and includes tools for edge detection, corner detection, various filters, optic flow, tracking, blob analysis, Web cam tools for real-time applications, and much more. It also includes many implementations of traditional algorithms such as Canny. It was developed for GNU/Linux but as the GUI is largely separate, porting to other platforms should be straightforward.
libptp is a Picture Transfer Protocol support library. It is used for downloading images from PTP cameras. It currently works with most modern cameras from the following vendor: Kodak, HP, Nikon, Canon, Panasonic, Olympus, Konica, Minolta, Fuji, Ricoh, and Sony. This package also contains "ptpcam", the tool used to tweak camera properties and perform some basic operations.