Emgu CV is a cross platform .Net wrapper for OpenCV
Libraries and command line tools for medical image processing.
High performance image processing library in C++
object-based image analysis framework
Multi-platform API for Image Processing systems in Life Sciences
OTB is an open-source C++ library for remote sensing images processing
A Library for Interactive Modelling and Visualisation
Open source library for processing arrays and matrices
C++ collection mostly for image processing