Increase quality for conversion PNG to AVIF

[Rombersoft]

Is your feature request related to a problem? Please describe

I've just converted PNG with size 235Kb to AVIF with 10Kb using the 13.5.0 library version and the result is very very bad picture quality.
I compared the result with the native Linux application ImageMagick (convert) and the result was 21Kb, and the picture quality is far better.

Describe the solution you'd like

I want to improve quality. Or maybe, it's possible to set quality and I don't know how to do it.

Describe alternatives you've considered

I assume that you can add the possibility of choosing a compression degree

Additional context

You can convert PNG photo to AVIF via your library and image-magick native and compare results

[dlemstra]

What is the exact NuGet package that you are using?