Image enhancement technique from dolphin file manager

Hi, I am using Dolphin file manager in Ubuntu 20.04.
When I have a grayscale image put in the dolphin file manager. when my mouse moves to that image, the image seems like been enhanced to high Contrast. And the performance is very good.

Just wondering what kind of algorithm may used for that. An example of an image is here:

Thanks for the help.

helped needed ! Anyone know the enhancement algorithm used ?

I believe this is a togamme effect in this case here. That’s a very common image transformation.

This is implemented in the framework KIconLoader for the effect KIconLoader::ActiveState. The implementation is at src/kiconeffect.cpp · master · Frameworks / KIconThemes · GitLab