NuGetMustHaves has a good summary of packages on NuGet with their build dates and OpenCV revs.
As of 6/29/2020:
- EmguCV is updated for OpenCV v4.3.0.3890 on 6/8/2020
- OpenCvSharp is updated for OpenCV v4.3.0.20200524 on 5/27/2020
EmguCV and OpenCvSharp are the 2 packages with recent builds and appear to be the better choices going forward.
Beware, EmguCV uses a dual GPL3/Commercial license (source) whereas OpenCVSharp uses the BSD 3-Clause License. In other words, OpenCVSharp is free for commercial use but EmguCV is not. EmguCV has superior documentation/examples/support and a bigger development team behind it, though, making the license worthwhile in many cases.
It's worth considering what your future use cases are. If you're just looking to get running quickly using a managed language, the wrappers are fine. I started off that way. But as I got into more serious applications, I've found building a C++ application has better performance and more potential for reuse of code across platforms.
