GIMP Version: 2.10.32
Operating System: Windows
OS Version: 11
GIMP Experience: Basic Level
URL or Image link: https://imgur.com/a/cynTAl7

List any relevant plug-ins or scripts:
GMIC

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I've got a ~1000 year old manuscript I need to enhance so it reads as well as possible when printed in black and white.
I was hoping there was a good way to clean it up and make the ink cleanly pop on a white background. I've been struggling with it, though I've tried several different GMIC filters. If you can give it a try and post what steps you took, It would be appreciated.

It would be awesome if anything could be done to salvage any text on the first two lines which are pretty faded.

You could try desaturating it and then run a levels or use curves. It's a bit of a challenge to find a happy balance.

That doesn't seem to help much (unless I'm doing it wrong). Would really appreciate it if someone would take the time to actually try with the sample I linked.

Are you able to post it here? One of us may be able to do it for you and give you the steps if yu have this problem again.

Oops didn't see your link. Will see what I can do when I have more time and if I am successful will let you knkow how it can be done

It's in the link in the initial post.

A difficult problem!
I would be hesitant to desaturate the image until you have something acceptable for printing. Treatment of separate areas and combining the results may be of benefit.
Here I have duplicated the original layer. Desaturated the copy using Colour to Grey (default values & Enhance Shadows selected) and changed it's mode to Soft Light. I then duplicated this layer. Overlay mode on these two layers gives a more contrasty result, but perhaps loses information in some areas.

I am sure others, more expert, will provide better solutions!

By the way.
Welcome to Gimp Chat

Thanks you two! Not quite where I was hoping we could get, but definitely given me some new things to try!

If you want to do the best in recovering the writing you will need to different type scanning. Perhaps a local college will be able to help. would make a great project for the computer science and medical departments.

https://www.smithsonianmag.com/history/ ... 180969358/

https://ideastream.pbslearningmedia.org ... etectives/

https://www.timesofisrael.com/1500-year ... eciphered/

Two more tries at this difficult problem!
The first of these I used my equal luminosity mask plug-in with the layer transition set to Hard.
The second one, equal saturation mask, again with Hard transition. I used brightness and contrast (curves) adjustments on each masked layer and set the saturation to zero.
Both of these plug-ins are dependent on Python 2.7 being installed.

As to whether the results are an improvement I cannot judge!

I think the first one there is the best so far. Thanks! Would you mind sharing any settings from the luminosity mask plugin?
thanks!

@MTW613

I cannot give any settings for the plug-ins (other than setting the transition to hard in the opening menu). It is just a question of playing with curves on each of the masked layers.

The reason I tried the equal saturation mask plug-in is because the colour of the vellum, the text and the contamination are of similar colour, but they have different saturation levels. While experimenting with it, I was able to see improvements in some of the more problematic areas. However, the result above was a compromise across the complete document. If you were to run the plug-in to achieve the best results for different regions, you could then flatten the layers of each run and stack them with masks which could be painted to allow the regions to combine.

I hope my explanation makes sense!

I have attached the two zipped plug-ins in case you do not already have them.

GIMP Version: 2.8.14
Operating System: Windows
OS Version: 11
GIMP Experience: Basic Level

List any relevant plug-ins or scripts:
GMIC

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You guys were so helpful with the previous section, I thought you might have some good ideas with this one. The challenge here is that the ink is so degraded, the letters actually aren't contiguous but, rather, have a bunch of crackled lines through them. Same as before, needs to be easily visible when printed in black and white. Please help!
thanks!

Well...this using the median blur / GEGL ColorWarp I described across on g-f.net

Another experiment to try and find an alternative process.

The original, adjusted with Curves to increase contrast.


The Red channel from this was copied into a new layer. Into additional new layers were copied the Green & Blue channels.
With the Green & Blue channels changed to Lighten-only mode we get this:


With Green & Blue channels changed to Subtract mode we have:


Both these methods result in a muddy grey background but, perhaps, make the characters clearer.

Thanks!