[k310]

I did some fiddling in GIMP, including edge detection filters. Not much progress.

The uneven illumination might call for working with regions separately. I didn't see an option to even it out. Bright areas seem blocked/saturated (in brightness, not color)

Unlike film, digital sensors seem better at letting you bring up detail in shadows and worse with highlights, which seem blocked.

"I don't use algorithms" (separately) unless they're incorporated in GIMP. More a photographer than anything else. Few words were readable.