Hi all,
Over the last few years I've been working on MMALSharp which is a C# API to the Pi camera. Instead of wrapping Raspistill/Raspivid in a Process call, MMALSharp calls the native MMAL library giving you a lot of configurable settings for your app. I'm choosing to post it officially on the forums now as I've just released the latest version on NuGet (0.4.3) and I'm at a point where I'm really happy with how it's performing.
The library is over at GitHub https://github.com/techyian/MMALSharp and the currently implemented functionality can be found here https://github.com/techyian/MMALSharp/wiki.
I'm still learning a lot about image processing, but I hope the library as it currently stands can be a positive contribution to people wanting access to the Pi camera via C#. Both Mono and .NET Core runtimes are supported.
Thanks,
Ian