XnView Software

I'm comparing the actions Enhance Focus, Enhance Detail, Enhance Edges, and Sharpen. I may be missing something obvious, but I haven't been able to find any documentation on what the different actions actually do. Does that documentation exist?

The kernel used are not the same

I understand that they use different kernels. What I'm looking for is either a qualitative description of the effect of different actions or a technical description of how the kernels differ. It's great to have so many options, but it's difficult to take advantage of them without any documentation describing what the options do.