Do you know any open source/free software C++ libraries to manipulate images in these formats: .jpg .gif .png .bmp ? The more formats it supports, the better. I am implementing a free program in C++ which hides a text file into one or more images, using steganography.
I am working under Unix.
ImageMagick can manipulate about anything and has interfaces for a dozen of languages, including the Magick++ API for C++.