I've created this full libvips binding for .NET in my spare time. It has a test-suite which passes with no memory leaks, it’s in NuGet, so it’s easy to install on Linux, macOS and Windows, and it has nice documentation.
The repo includes benchmarks which test the performance against Magick.NET, the ImageMagick binding for .NET. On that test, NetVips is 8x faster than Magick.NET.
None – on own initiative