aforge.net 

The AForge library is a core library of AForge.NET framework, which contains core classes used by other libraries of the framework and classes, which can be used independently for various purposes.

The AForge.Math library contains set of math utilities, which are used by other AForge.NET framework's libraries or may be used individually.

The AForge.Imaging library contains interfaces and classes for different image processing routines and filters. Full list of features is available on the project's web site.