Google Books PDF Files

November 14, 2011 10:59 AM

Why can't PDF files from Google Books downloaded via GooReader be modified in Adobe Acrobat? I need to modify the font size size so these books can be read on my Kindle. My copy of Acrobat Standard will not recognize these Google PDF files as editable. Why does Acrobat not recognize these PDF files?
posted by Raybun to computers & internet (11 answers total)

I'm usually not one to tell you to break protections on PDF files, but it sounds like there's something built into the PDF which can stop editing. I'm all about owning what you pay for though, so, try using PDF Unlock to get things handled. Only works if the PDF is 5MB or smaller though.
posted by deezil at 11:12 AM on November 14, 2011 [1 favorite]

Is the text in the PDF selectable otherwise? If not, perhaps it isn't text at all, but just an image of text, which of course won't be editable or resizeable.
posted by odinsdream at 11:15 AM on November 14, 2011

odinsdream; The text cannot be selected.
posted by Raybun at 11:31 AM on November 14, 2011

deezil; PDF Unlock did not find any restrictions.
posted by Raybun at 11:34 AM on November 14, 2011

If it is locked, then perhaps these instructions from a Lifehacker comment will work: http://lifehacker.com/396534/freeware-pdf-unlocker-enables-copypaste-functions-without-passwords?comment=42468835#comments

Also another website for unlocking is http://www.unlock-pdf.com/

Disclosure: I haven't tried either one myself.
posted by gearspring at 11:46 AM on November 14, 2011

The Google Books project constructs the PDFs by scanning paper books and assembling the series of images for each book into a PDF. While Google did OCR these images to enable searching the content of these books, OCR technology is not good enough to reliably reverse engineer the text and page layout of a scanned book without human input (and Google has not done this additional work). Since they're just a bunch of images, they do not contain "text", and thus adjusting the font size size has no effect. If you want actual reliable text versions of old books, you'll have to go to one of projects that starts with the scans and produces real text from them (such as Project Gutenberg).
posted by RichardP at 11:47 AM on November 14, 2011 [6 favorites]

What happens if you convert those files from pdf to mobi with calibre?
posted by 8dot3 at 11:47 AM on November 14, 2011

Yes, as 8dot3 says you need to convert these files to .mobi using Calibre. The resulting OCR will be problematic, most likely mixing up "rn" with "m" and similar issues, depending on the resolution of the original document and the font.

You may also get random special characters too, %^ especially. Odinsdream almost certainly hit the nail on the head---you have pictures of text, not "text", which is also why your filesize is probably larger than you may otherwise expect AND the text is probably blurrier.

You can't up the font size enough on the Kindle to make it legible? You may be better off trying to permanently zoom the document instead of adjusting font size.

(Also, if it's fully free on google books, it's also likely fully free on the Kindle store. Potentially worth checking out.)
posted by TomMelee at 12:35 PM on November 14, 2011

8dt3: Tried to convert to .mobi with no results. These titles are too obscure to be available on Gutenberg.

Thanks All
posted by Raybun at 4:33 PM on November 14, 2011

When you download it from google books can you download it as an epub instead of PDF and then convert to mobi?

I have a bunch of obscure books from google books I've read with Stanza on my iPad but I used the epub format. They are mostly readable with some OCR errors.

I don't have a kindle so I don't know about converting from epub to mobi, so I'm not sure if that part will work.
posted by interplanetjanet at 5:02 PM on November 14, 2011

I just went back to Google books and looked at one of the books I downloaded before and now and I see what your problem is. You have to download it as epub not PDF. The PDFs from Google books are not OCRed so you can't read it as an ebook. You could use Adobe Pro or some other software to OCR the PDF file if you wanted to but it is easier to just download the epub file.
posted by interplanetjanet at 5:13 PM on November 14, 2011