Mathematical principles and software algorithms used in GIMP/Photoshop image filters (plugins). What literature describes it in detail?

Question

Books

Today in the field of image processing there is a hype around image recognition, so almost all the literature is biased in this area. And I would like to read about a completely different image processing, the one that is implemented in the filters (built-in and plug-in) GIMP / Photoshop. I'm mainly interested in different filters in the categories (according to the GIMP menu): Enchance, Distorts, Blur, Edge-Detect.
As an example on the topic of "restoring" images: here is what I found on deconvolution and the use of the Wiener filter for this purpose in the documentation for the refocus filter - pdf(p. 6, Technical background). A very dry description is a description of half a page (the author apparently assumes that those who are in the subject know the sources themselves, and for those who are not in the subject, such a description will do), but I would like normal literature, where the topic is revealed, starting from mathematical foundations, through algorithms and up to specific implementations in examples.

Answer 1

https://habrahabr.ru/post/147828/ - a lot of interesting things are considered here. The same author has a continuation of articles.

Answer 2

Dan Margulis:
Very popular and chews on many algorithms with examples. Read interesting.

Answer 3

The tasks you are interested in are mainly related to the theory of digital signal processing.
Here is a good free book (you need to know elements of higher algebra):
Signal Processing for Communications by Paolo Pran...
Here are the corrections to it: Errata