Question: From where can I get image processing libraries in C# .Net?

Answer: 
There [emguCV](http://www.emgu.com/wiki/index.php/Main_Page) (for .NET) that is based on C++ OpenCV, which is very popular.
I know a third-party toolkit named leadtools that provides many image processing functions. Also, it supports hundreds of image formats. You can find more information here:
<http://www.leadtools.com/sdk/image-processing/default.htm>