Accord.NET Framework - Machine learning, computer vision and statistics framework for .NET
OpenCV - OpenCV is the world's biggest computer vision library
BoofCV - BoofCV is an open source library written from scratch for real-time computer vision.
libdwt - A software library for computation of the discrete wavelet transform that is primarily implemented...
SimpleCV - SimpleCV is an open source framework for building computer vision applications.
Google Vision AI - Cloud Vision API provides a comprehensive set of capabilities including object detection, ocr, explicit content, face, logo, and landmark detection.