Well thank you ! i'm glad you like the result.
Here I just did an attempt on a more common scan quality without any resolution improvement:
http://image.noelshack.com/fichiers/2021/34/2/1629792009-cp3-05.jpgIt's basically some photoshop editings. But the process is not very easy though, so I compiled all the things that I experimented and found in several photoshop scripts in order to make it kinda "automatic". (or at least make it way more quick to do)
of course the quality of the final rendering will be good depending on a good quality and scan resolution. And there is of course always some handcraftings at the end because every scan is different.
Anyway my method aims to touch the original colors as little as possible because I want to keep the oldschool aspect. Of course, once the black line is extracted, a real restoration with crisp and clean (even modern) colors is possible with this method, but it would have to be done completely by hand and it would take a very long time.
This attempt right here took me around 10 minutes to complete. Of course it could be better. it's just an example I did now.
I will explain my method more in details when it will be more effective.
[ EDIT ]
I searched for a better "old yellow removing" on another piece this afternoon. I get those results :
http://image.noelshack.com/fichiers/2021/34/2/1629816520-pirates-03-14-test.jpg