Basically this is a converter for the PPM file format as used on the Ray Tracing in One Weekend tutorial.
There are several versions of it, the originally coded in C++20, and the later port done to C#.
Afterwards as I started discussing the performace of Native AOT in .NET 7 preview, I needed to provide some numbers for more arguments, hence how the Go, D, and Java versions came to this repo as well.
In C# and C++ cases I only focused on Visual Studio support, although the C# version is cross plaform, whereas the C++ focus on Windows APIs.
Everything else uses their standard build workflows.
If you don't happen to have PPM file with the P3 format lying around, there is one on the samples folder.