The sample images are not in the repository

[alanmcgovern]

    /// <remarks>
    /// Images are taken from here (size ~ 1.1GB): https://qoiformat.org/benchmark/qoi_benchmark_suite.tar
    /// </remarks>
    public const string RootImagesDirectory = @"E:\Tests\qoi_benchmark_suite\images";

Hardcoding that path in the tests makes things a little harder to use. Do you have a preference on how to change this (safely) to a relative path to simplify running the tests for contributors?

[NUlliiON]

The archive with the images used for testing (and for benchmarks) is too large, so I did not add it to the repository. I think I'll add the option to download "test data" when the user is running tests.

[alanmcgovern]

If you have a preference on how you'd like to add the ability to reference an out-of-repository path for these files just let me know.

I can contribute a patch which simply looks for a side-by-side directory, or a patch which adds msbuild magic to emit something as part of the build so it can be configured to any location (defaulting to side-by-side).