XnView Software

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 ...

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?