MobileRead Forums - View Single Post - Smartphone Book Scanning: What's Still Missing for PDF and EPUB?

notimp · Today, 06:01 AM

4/5 of the manual work at the checking the formerly scewed parts of the pages for OCR errors (which is the same process in which I check for page numbers that stayed in after crop, and for correct pagebreak removals (paragraph merging) -- but its all mostly done because of double checking for OCR errors, pagebreak removal can be automated via Regex - 2, 3 left over pagenumbers that become part of the main text arent the world) - this is all one step though - where I'm comparing every page of the pdf against the epub text and making changes in the epub manually.

1/5 of the time: Pulling headline formatings onto the same level ("you all are h2 headlines"), merging pages that have unneeded chapter breaks (md to epub script looks at headline tags in the .md), adding additional chapter breaks and headline formating for the headlines that were missed by OCR (they usually never are shown as plain text and always have at least special formating, but might miss the headline tag), automatically (Sigil has a feature for it) recreating the TOC (epubs table of content), making sure the epub has the right title and author name and language tag in the metadata.

The second part maybe takes 5-10 minutes at most.

Also - If I just want to have an epub read to me with TTS I can skip all of them, aside from headings alignment and toc creation. (Because I create .wav files per chapter (based on the TOC). and then srts based on the .wavs).

Because the issues fixed in the 4/5 step are usually so minute - that for the unconcerning reader they dont matter. For a publisher they do. As in they almost never are text recognition errors anymore. The OCR almost always is right. Its just a split paragraph or a missed pagenumber out of 300 that I'm manually removing. And I'm doing this mostly because I have to check for huge OCR mistakes if I want to act responsibly. For personal use - I could almost skip that 4/5 step.

On perfect test books:

Children/Young adults literature. With Inserts in the text where a third person like a narrator speaks, ideally with an Image indicating those sections.

I dont have public domain books, that fit, but I can give you a recommendation.

You arent looking for books that are "very hard" to OCR (if you need that - look for scientific texts with many different nested layout levels, footnotes, and image subtitling) to test, you are looking for "short texts" with several challenging forms of "usual, normal" layouting that are a third of the length of a normal book when transforming them into a perfectly formed epub.

To learn.

My go to is always Die drei ??? und das Gespensterschloss by Robert Arthur, German edition - Where the earlier releases always had the Narrator (Hitchcock) pitch in at certain points of the Text.

Because it will teach you the shortcomings of conventional OCR (tesseract) on conventional book formating quite quickly.

Should you know the sources the AI bros frequented for training material for ChatGPT or Fable/Opus, you'll find pdfs of that book there as well. Those sources even have wiki pages, but I'll still not link them here. Or why not buy a used german book from an online retailer? Has to be a release from 2004 or before, because afterwards Kosmos lost the rights to use the Hitchcock branding.

The parts I usually look at in those books look like these - (Three pages for reference):

https://imgur.com/a/RjcFYJO

As for smartphone scans - make them yourself, test different smartphone cameras, childeren literature prefered, because "one entire book" is about a third of the size/volume.

edit:

Oh, and Shadowrun - 2XS by Nigel Findley (english or german edition) for the other type of challenging formating I was mentioning.

So first paragraph of a page with no indents, others with. Like this -

https://imgur.com/a/tugXYYQ

But imagine that on page 1 a sentence ended and on page 2 a new sentence started. What is it? A new Paragraph? A new scene after a scene break? A continuation of the previous paragraph?

Because the previous sentence in this case (on page 1) ended in a character that is not a sentence end mark ([^(.|?|!|<|>|«|‹|"|:|“)]), we would fold the actual starting paragraph on page 2 together with the previous one (possible via regex). But what if at the beginning of page 2 a new sentence had started?

Today, 06:01 AM	#5
notimp Addict Posts: 256 Karma: 892441 Join Date: Jul 2010 Device: K2i	4/5 of the manual work at the checking the formerly scewed parts of the pages for OCR errors (which is the same process in which I check for page numbers that stayed in after crop, and for correct pagebreak removals (paragraph merging) -- but its all mostly done because of double checking for OCR errors, pagebreak removal can be automated via Regex - 2, 3 left over pagenumbers that become part of the main text arent the world) - this is all one step though - where I'm comparing every page of the pdf against the epub text and making changes in the epub manually. 1/5 of the time: Pulling headline formatings onto the same level ("you all are h2 headlines"), merging pages that have unneeded chapter breaks (md to epub script looks at headline tags in the .md), adding additional chapter breaks and headline formating for the headlines that were missed by OCR (they usually never are shown as plain text and always have at least special formating, but might miss the headline tag), automatically (Sigil has a feature for it) recreating the TOC (epubs table of content), making sure the epub has the right title and author name and language tag in the metadata. The second part maybe takes 5-10 minutes at most. Also - If I just want to have an epub read to me with TTS I can skip all of them, aside from headings alignment and toc creation. (Because I create .wav files per chapter (based on the TOC). and then srts based on the .wavs). Because the issues fixed in the 4/5 step are usually so minute - that for the unconcerning reader they dont matter. For a publisher they do. As in they almost never are text recognition errors anymore. The OCR almost always is right. Its just a split paragraph or a missed pagenumber out of 300 that I'm manually removing. And I'm doing this mostly because I have to check for huge OCR mistakes if I want to act responsibly. For personal use - I could almost skip that 4/5 step. On perfect test books: Children/Young adults literature. With Inserts in the text where a third person like a narrator speaks, ideally with an Image indicating those sections. I dont have public domain books, that fit, but I can give you a recommendation. You arent looking for books that are "very hard" to OCR (if you need that - look for scientific texts with many different nested layout levels, footnotes, and image subtitling) to test, you are looking for "short texts" with several challenging forms of "usual, normal" layouting that are a third of the length of a normal book when transforming them into a perfectly formed epub. To learn. My go to is always Die drei ??? und das Gespensterschloss by Robert Arthur, German edition - Where the earlier releases always had the Narrator (Hitchcock) pitch in at certain points of the Text. Because it will teach you the shortcomings of conventional OCR (tesseract) on conventional book formating quite quickly. Should you know the sources the AI bros frequented for training material for ChatGPT or Fable/Opus, you'll find pdfs of that book there as well. Those sources even have wiki pages, but I'll still not link them here. Or why not buy a used german book from an online retailer? Has to be a release from 2004 or before, because afterwards Kosmos lost the rights to use the Hitchcock branding. The parts I usually look at in those books look like these - (Three pages for reference): https://imgur.com/a/RjcFYJO As for smartphone scans - make them yourself, test different smartphone cameras, childeren literature prefered, because "one entire book" is about a third of the size/volume. edit: Oh, and Shadowrun - 2XS by Nigel Findley (english or german edition) for the other type of challenging formating I was mentioning. So first paragraph of a page with no indents, others with. Like this - https://imgur.com/a/tugXYYQ But imagine that on page 1 a sentence ended and on page 2 a new sentence started. What is it? A new Paragraph? A new scene after a scene break? A continuation of the previous paragraph? Because the previous sentence in this case (on page 1) ended in a character that is not a sentence end mark ([^(.\|?\|!\|<\|>\|«\|‹\|"\|:\|“)]), we would fold the actual starting paragraph on page 2 together with the previous one (possible via regex). But what if at the beginning of page 2 a new sentence had started? Last edited by notimp; Today at 10:18 AM.