PDF to epub conversion with Android

[ColetteS]

Is there a way to properly convert a PDF book file to an epub file, via an Android app or mobile website without massive loss of layout and image placement? To clarify, I am not looking to create ebooks, but to simply convert PDF to epub (or another ebook format), so I can import them into a single library/reading app.

Some background: I traditionally used Sigil for this task until last year, when I was the victim of a catastrophic hit and skip car accident that left with massive mobility issues, including only partial use of one arm, and no use of the other. My injuries have made using laptops, PCs, and their equipment (keyboards, mouse) extremely difficult. I am frequently bed-bound, and only able to sit in certain positions. I have special equipment that holds a large screen Android tablet (11") in front of me to stabilise it, and leaves my partially working arm free to do typing and tasks, with the use of an orthopedic-designed tool that works similar to a stylus, connected to my working hand.

I work from home in the research sector, so I have a extremely large e-book library, and it's pivotal to keep those books in one app, for the sake of tags systems and organisation, for quick reference between books while doing research.

PDF is extremely difficult for me as a format, due to the nature of pinching and zooming, and the limitations of my mobility, so I have a much easier time with epub and other ebook formats.

Unfortunately, most academic and research booksellers and journals release on PDF. There has been some movement towards epub and kindle format inclusion, but very little so for anything published pre-2018.

I am in no way fluent in coding, and have some limited knowledge of ebook design from using Calibre and Sigil before my injuries, but I do understand that Android/mobile based pdf to epub converters (e.g., Zamar, ePUBator, etc.) are not capable of lossless format rendering, due to the structural differences between PDF and epub, at least on the scale of something as large as a book.

I also have very little weight-bearing ability, and do much of my pleasure reading (which also entails a lot of academic reading work) on e-ink e-readers, since they are small and light weight enough for me to physically hold with my working arm for extended periods of time. PDF in general is a nightmare on such a small screen. On average, I spend 10-12 hours a day reading between the tablet and e-ink reader.

My question is, does anything exist as a work around, that would produce semi-decent conversions from PDF books to epub on Android? I am willing to learn/take courses, if there is a more complex method that requires application design or development, as most of my injuries are permanent and this is likely to be a life long issue, but I wouldn't know where to start or what those courses/learning systems would even be.

I currently use a Samsung Galaxy Tab S7, running Android 13.

I don't know if this is even possible, but the frustration over the last year in trying to make it work has been incredibly demoralising. If anyone has any suggestions, I would hugely appreciate them. Thanks

[Quoth]

Usually not.
PDF is not a source or reflowable content, but for end of distribution or print to paper.

If it's not image based, then copy & paste a bit at a time to MS Word or LO Writer (or try opening in them).
If the content is very non-sequential or columns or multiple layers you may need to convert to image based PDF.
If image based do OCR and proof.

In any case fixing up in LO Writer or MS Word, then Save As Docx (only edit odt in LO Writer, but can edit docx in Word) and use Calibre to convert to epub.

Direct PDF to epub is mostly a failure.

[Tex2002ans]

Originally Posted by ColetteS

My question is, does anything exist as a work around, that would produce semi-decent conversions from PDF books to epub [...]?

Another option is to use the fantastic:

• k2pdfopt

This can take your complicated PDFs (like multi-column journal articles) and re-lay them out for a smaller device.

This may make reading PDFs on your current devices much more bearable. (No panning/scanning!)

Originally Posted by ColetteS

Is there a way to properly convert a PDF book file to an epub file, via an Android app or mobile website without massive loss of layout and image placement?

Sadly, no.

PDF->EPUB is already a very manual+labor-intensive task.

If you have access to a computer, there are much more powerful PDF->whatever tools though.

For example, ABBYY Finereader is what I use.

This will OCR the document + spit out whatever formats you need. (Including DOCX, EPUB, etc.).

The much more expensive version would even allow you to drag/drop into a folder, and have Finereader do lots of automated steps for you... but, of course, this would lead to less-than-ideal output. Yes, better than 0, but... reading that automated EPUB would be rough.

Originally Posted by ColetteS

I am willing to learn/take courses, if there is a more complex method that requires application design or development, as most of my injuries are permanent and this is likely to be a life long issue, but I wouldn't know where to start or what those courses/learning systems would even be.

Sadly, a lot of this stuff would probably require LOTS of manual intervention/mobility.

But, I've written hundreds of posts over the years about PDF->ebook conversion.

One of the latest was in the fantastic:

• 2021: "Tutorial-from Paper Book to Ebook PDF - 400 pages in 4 hours"

and:

• 2020: "Optimize PDFs from archive.org for E-Ink devices"

I go over (and link to) a ton of tools/methods I've used over the years.

Mostly using Finereader + Sigil/Calibre.

- - -

For example, once I output PDF->EPUB out of Finereader, I run one set of "Saved Searches" (a list of Find/Replaces), and get a relatively readable EPUB out of it.

See the example PDF+EPUB documents in Post #14 of the Archive.org thread above.

All I did was:

• Run Finereader on the original PDF.
• Output PDF->EPUB.
• Open EPUB in Sigil.
• Run the Saved Searches.
• Resave "Cleaned" EPUB.

Compared to the original PDF (and especially the crappy "EPUB" version from Archive.org), I think my few-minute conversion is pretty usable.

Originally Posted by ColetteS

I don't know if this is even possible, but the frustration over the last year in trying to make it work has been incredibly demoralising. If anyone has any suggestions, I would hugely appreciate them. Thanks

Your best bet would probably be PDF->PDF using k2pdfopt.

That wouldn't require any "conversion" to other formats, and hopefully it'll reflow your documents to use on your tablet.

Whatever magic Willus did with that tool, it works on all sorts of documents.

(I first tested it years ago on two-column journal articles, and was so surprised that it handled it perfectly!)