Check out the Intel® Integrated Performance Primitives (Intel® IPP)  C# support sample  ( Download it from Intel IPP Sample Page), it is included in part of Intel IPP samples for Windows.  The sample is located in Intel IPP sample directory \ipp-samples\language-interface\dotnet-cpp

It demonstrates how to use Intel IPP when developing applications in the Microsoft C# environment. Includes wrapper classes to support Intel IPP string manipulations, image, signal processing, color conversion, cryptography, data compression, JPEG, matrix and vector math, etc.

Additionally, there is a complete white paper to address C# support in Intel® Performance Libraires including Intel IPP and Intel® Math Kernel Library ( Intel MKL), please visit here for more reference.