Image processing, highlighting hidden details

[ReneZ]

When stretching the color space considerably, only the best quality of digital images should be used, otherwise compression artifacts will be plainly visible.

These images were made from the 400 dpi scans of 2014, but I smoothed them before.
Also I used a mask (4x4 pixels) to blank out 'known' text and drawings.
All that was done with home-brewn algorithms.

I will add the other folios as soon as the web host is behaving normally again.

Can you tell us what are the areas or an example of an area that cannot easily be explained please from the images provided above

I have not even looked at everything in detail. I would invite everyone to try, but it works best with a large screen.