VIPS is a small, quick and memory-conservative 2D image processing C and C++ library. It comes with over 300 functions, for arithmetic processing, histograms, convolutions, morphological operations, frequency filtering, colouring, resampling, statistics and others. It supports most common raster image formats (PNG, TIFF, JPEG, FITS, OpenEXR), or chain to ImageMagick/GraphicsMagick.
The C++ Mathematical Expression Toolkit Library (ExprTk) is a simple to use, easy to integrate and extremely efficient run-time mathematical expression parser and evaluation engine. ExprTk supports numerous forms of functional, logical and vector processing semantics and is very easily extendible.