How to equalize brightness?

[ghostmansd]

I think I ask a hard question, which probably has no answer, but I'll try. Is it possible to equalize lightness of the picture? In other words, to make the same effect like in Book Restorer. You can see picture before and after below (be careful, big images!).

[fmw42]

If you are on Linux/Mac or Windows/Cygwin, you can try my textcleaner script from the link below. Otherwise, you need to play with -lat (local area threshholding), which is the basis of the script.

[anthony]

There are a number of ways. Such as -lat, and dividing the image by a blurred version of itself.
But really Fred's Text cleaner is a good starting point.

[ghostmansd]

Thank you very much!