FreeImage is a library project for developers who would like to support popular graphics image formats (PNG, JPEG, TIFF, BMP and others). Some highlights are: extremely simple in use, not limited to the local PC (unique FreeImageIO) and Plugin driven!
Geodesy based library (geodetic and geocentric functions)
geoStarsLib has functions for dealing with many geodesy-based problems found in positioning, pointing, and surveying situations. It is useful to determine absolute position on the earth, pointing vectors, coordinate transformations, and other functions.