[Tex2002ans]

Originally Posted by willus

The k2pdfopt app fits most of what you want (e.g. command-line, linux). It has a thread here in the PDF forum on MR.

Fantastic work as always. Yes, if you wanted to keep it in PDF form... your tool is always best. :P

Originally Posted by ctop

An example of the PDFs I am looking at is this:

https://archive.org/details/smtliche...ge/n8/mode/2up

(This is the item page, the download link is here

https://archive.org/download/smtlich...r16goet_bw.pdf

Any help appreciated

But if you want to take steps in making the PDF a proper ebook:

I grabbed this book and ran it through Scan Tailor Advanced + Finereader 12.

1. Finereader 12 did a MUCH better job with colored PDF's "yellowed pages", and had no issues creating a B&W version.

I attached it as [Finereader][BW].

(You can see how much better 12 converts compared to 8.)

Side Note: I manually erased markings from the first few pages, so they look pure white... just ignore that in your comparisons.

Note: Alternatively, you could've fed color images into Scan Tailor directly (it has 3 different methods to convert to B&W/Grayscale + you can mess with the thresholds).

2. I exported the B&W PDF into PNGs, then ran that through Scan Tailor Advanced.

I spent about an hour going through the various stages, and Scan Tailor did a FANTASTIC job at automatically picking all correct boxes. The page edges are nearly all gone.

I would say 95%+ I didn't have to touch at all.

Side Note: Despeckling + Outputting has gotten so much faster/better compared to how it used to be. And I only had to use Despeckling on a handful of pages to remove the occasional stray dots. (Being able to see the before/afters marked with red is an enormous help. This is one step where GUI beats the pants off of pure commandline.)

3. I took the Scan Tailor images, and reimported them into Finereader 12, ran OCR, and output as:

PDF = [ScanTailor][Finereader][BW].pdf. (30 MBs is too large to attach, so here's a download.)
EPUB = [Finereader].epub.

You can compare the text, and see how much more accurate 12 is compared to Archive.org's "EPUB". (Most importantly, the headers+page numbers are nearly all automatically removed and not clogging the text.)

4. I took Finereader's EPUB and ran it through my usual "Finereader cleanup Regex":

Attached it as [Finereader][CodeCleanup].epub.

Comparison Images

Archive.org Color PDF + Finereader B&W + Scan Tailor Cleanup: