Quote:
Originally Posted by ctop
[...] the background of the page, which has become yellow. So the contrast is low and the text becomes unclear, [...]
I would prefer to use a commandline on a Linux based system, if such a tool is available here.
|
GUI-based:
Scan Tailor Advanced:
https://github.com/4lex4/scantailor-advanced
There isn't another tool like it.
If you want commandline, then there's nothing better than ImageMagick, but you'll have to come up with all the tweaks yourself.
There was also
"What’s your “image rehab” routine?" from 2013 which discussed some image cleanup ideas. Although that mostly focused on cleaning up images within scans.
Side Note: Archive.org's B&W versions are usually okay. In this case, it requires lots of manual intervention. Go back to the color PDF (or like GrannyGrump mentions in the thread above, use the original JPEG2000 files), and do all your cleaning from there.
This specific file also has a lot of bleeding through the pages, so that may make your job extra harder when trying to darken text.
Quote:
Originally Posted by ctop
also the files are quite big. So I wonder if somebody knows a good way to trim the PDFs for ereaders.
|
Scan Tailor Advanced should be able to do all the chopping/cropping/contrast adjustments for you. But if you need even more PDF tweaking beyond that, then there's
k2pdfopt, by willus.