PDF to Kindle: The unobtainable Holy Grail of ebooks

[DiapDealer]

Originally Posted by HarryT

You are wrong. Most PDF documents do NOT contain text. Some have a text "layer" in them, which DOES contain searchable text - this is generally added by OCR.

And that text layer (if it exists at all) can be of very dubious quality.

[HarryT]

Originally Posted by DiapDealer

And that text layer (if it exists at all) can be of very dubious quality.

Exactly - it's generally "raw" OCR, added so that you can search the document.

[physics]

There's a lot of negativity for pdfs here (which is understandable), but for those of us who need long and difficult equations, really there's no other formant available besides latex to pdf or postscript. Epub and mobi just don't support complicated equations.

Anyway, back to the question at hand, do you really need to convert your pdf to ebook format? I've managed to get along quite well by cropping pages, adding bookmarks, etc. There are a lot of tools out there for manipulating pdfs. I think learning to live with pdfs on your ereader might be less frustrating than trying to convert it.

[Daveoc64]

I'd like to note that I'm not anti-PDF, far from it in fact!

It's just not an ebook format!

[shinew]

iPad+GoodReader = PDF Win

[HarryT]

Originally Posted by shinew

iPad+GoodReader = PDF Win

True, but entirely irrelevant to a Kindle discussion.

[shinew]

Originally Posted by HarryT

True, but entirely irrelevant to a Kindle discussion.

it means give it up on the Kindle & get something more suitable for general PDF reading. iPad currently probably has the best apps for it.

[amoroso]

Originally Posted by tentimes

I am confused about why there is no program out there that can take the textual information in a pdf book, plus the index (bookmarks) and turn it into a an indexed book.

A PDF document is a software program containing instructions written in a restricted subset of the PostScript document description language, which is a full blown stack-based programming language. Extracting text from a PDF document is difficult because it is not stored in specific sections of the file, but scattered in difficult to predict ways among the instructions that generate the document layout. Consider for example the following pseudocode fragments that print the same "book" string:

PRINT "book"

PRINT "b" + "o" + "o" + "k"

PRINT "bo" + "o" + "k"

string = { "b", "o", "o", "k" }
FOR i IN string
PRINT string($i)

There are countless more equivalent code fragments, all different, that generate the same text. Each of the fragments includes in a different way the text or part of it. Extracting the text, and even locating it, is difficult. Something similar happens with instructions in a PDF file. A PDF conversion utility is actually a program-analyzing tool.

[DiapDealer]

There's a lot of negativity for pdfs here (which is understandable), but for those of us who need long and difficult equations, really there's no other formant available besides latex to pdf or postscript. Epub and mobi just don't support complicated equations.

Actually most people are fine with PDF's. I know I am (except on 6 inch screens). Most of the negativity comes into play when someone wants to turn a PDF into something else. A PDF just doesn't convert well... easily. I doubt it ever will.

[tentimes]

Well I tried pdfmasher and it is doing a good job of extracting the text - I would love to know how it does it.

It's just that I have spent so much money on pdf books and I am determined that I am not paying for them again.

My best solution to date now is to use pdfmasher or bliss and send to amazon for convert.

I am sure that someone will complete the next step and write a program to do a proper conversion, with a bit of AI logic. The sooner the better for all of us who bought technical books on pdf

[DiapDealer]

I am sure that someone will complete the next step and write a program to do a proper conversion, with a bit of AI logic. The sooner the better for all of us who bought technical books on pdf

I seriously doubt that will ever happen. PDF formatting varies wildly from document to document. So much so, that some sort of manual intervention and/or manipulation will almost certainly be required for any quality PDF conversion. Automatic quality conversions is pretty much out of the question.

[alsaan]

The PDF format just doesn't preserve enough information about the structure of the document to allow further conversions. I like to think of it as a "lossy" text format, of sorts.

Trying to extract a properly formatted document from a PDF is akin to hoping to recover a full-sized image by "enhancing" a small thumbnail.

[Zeebra]

Originally Posted by tentimes

Well I tried pdfmasher and it is doing a good job of extracting the text - I would love to know how it does it.

It's just that I have spent so much money on pdf books and I am determined that I am not paying for them again.

My best solution to date now is to use pdfmasher or bliss and send to amazon for convert.

I am sure that someone will complete the next step and write a program to do a proper conversion, with a bit of AI logic. The sooner the better for all of us who bought technical books on pdf

I was playing around with PDfmasher as well and it's fairly cool. Very easy to remove headers and footers but I was having issues getting footnotes to work.

[DiapDealer]

I was playing around with PDfmasher as well and it's fairly cool. Very easy to remove headers and footers but I was having issues getting footnotes to work.

I've found the footnotes function to be a tad flaky with PDFMasher, but I've gotten pretty close a few time with documents that had buckets of footnotes. Close enough that I didn't mind fixing up the results by hand. And it seems to be getting better all the time. The different sorting abilities makes it pretty powerful and it's by far my favorite for very simply formatted novels, but losing italics really annoys me when converting PDF's (not PDFMasher's fault, I know).

[Blossom]

Originally Posted by DiapDealer

I've found the footnotes function to be a tad flaky with PDFMasher, but I've gotten pretty close a few time with documents that had buckets of footnotes. Close enough that I didn't mind fixing up the results by hand. And it seems to be getting better all the time. The different sorting abilities makes it pretty powerful and it's by far my favorite for very simply formatted novels, but losing italics really annoys me when converting PDF's (not PDFMasher's fault, I know).

So it doesn't convert italics? I was going to give a shot but I do get good results with Acrobat Pro on Novel PDFs. It pulls the styles from the PDF just fine as long as the PDF is tagged.