Handling Pdfs

[MarjaE]

Hi,

I have been using a Kindle Dx to read pdfs. (As well as an Iriver Story Hd, but that has a small screen.) I have coordination problems, so I can't use touch devices, and can't switch to a newer faster device.

Many of the ones from the Internet Archive, DriveThroughRpg, and so on are big pdfs. It can be hard to get to the right place in these pdfs, so can anyone suggest Mac tools to help compress these pdfs, or split them into smaller sections without expanding them?

Librerator can handle djvus, but the basic Kindle system can't.

On the Mac, I have a couple tools to split pdfs, but they expand them, and to compress pdfs, but they are slow and unpredictable. Even something which could check which pdfs are compressible would help.

P.S. cross-posting to Apple's support site for the other side of thinhs.

[Cinisajoy]

If you are reading public domain books, have you looked here for the kindle editions?

[ab7vf]

Hi MarjaE

Try "PDFSAM" ...open source splits on page numbers .. Been a while since I used it but it worked well for me

Jim

[MarjaE]

Originally Posted by Cinisajoy

If you are reading public domain books, have you looked here for the kindle editions?

Now I have, but so far they aren't here. And very few are on Gutenberg.

[HarryT]

You can use any PDF printer (ie a printer driver that "prints" to a PDF) to split a PDF. Just print the desired range of pages from the original document to the new one.

[MarjaE]

Yes, I knoe. I can split them into smaller sections, but that usually expands them.

For example, I just downloaded another manual for research. It was 19.8 mb.

I decided to split off the relevant pages. And the resulting exceprts add up to 630.4 mb.

I have compression software but trying to get to less than 19.9 mb makes everything too blurry.

I can use another route and strip out the color first [in Preview], and then compress [in Pdf Compress Expert] to get to 17.1 mb. Neither of my e-readers can show color anyway.

[johnnyb]

The problem is that most Mac tools rely on the OSX PDF engine which is known to do what it pleases (e.g. expand the size)... I can recommend PDF Scanner (https://itunes.apple.com/de/app/pdfs...10968114?mt=12). It lets you OCR the files and the adjust size for compression. Sometimes gives great results.
Another, although more expensive option, is of course Acrobat Pro. Their ClearScan technology usually produces much smaller files especially for longer documents because it synthesizes fonts from the original documents for OCR, thereby drastically reducing the file size. Just be aware to never save the docs with anything OSX PDF Kit because that will irreversibly ruin the OCR layer. Works best in combination with the monochrome PDFs that you are producing in Preview, or other monochrome PDFs that you could produce in Acrobat.
My usual workflow for Internet Archive PDFs:
- remove unnecessary front and back cover pages
- Crop document in Briss
- Convert to Tiffs with Acrobat
- Reassemble PDF in Acrobat
- Treat with ClearScan
-> small fast PDFs on any reading application including Kindle and Koreader

[Yourcat]

Ghostscript should work, see http://stackoverflow.com/questions/1...th-ghostscript / http://www.cs.virginia.edu/~weimer/pdfsplit/pdfsplit for examples.

Anyhow I didn't split PDF files for a long time, currently I prefer creating huge PDF files from multiple sources. Searching in one file is usually more convenient for offline clients.

PS: http://pages.uoregon.edu/koch/ has a Mac pkg - I don't have a Mac so I won't test it.

[Pajamaman]

Adobe Acrobat Pro can split pdf files. If the pdf is image based, you can also save the pdf as a series of jpgs, clean up the image quality, then recombine them. It is a useful piece of software if you deal a lot with pdf files.

I have only used the Windows version.

[HarryT]

Acrobat is an awfully expensive solution to the problem (unless you already happen to have it, of course). There are a number of free tools available for splitting PDFs. One free and open source one that I've used, and which works very well is:

https://sourceforge.net/projects/pdfsam/

[MarjaE]

Thanks. I checked their help site, but it is full of animation, so I can't read it:

http://www.pdfsam.org/

[MarjaE]

I'm currently using Pdf Toolkit+. It splits and compresses, though it doesn't have the custom compression options some other apps offer.

[MarjaE]

So is there a better way to prep pdfs for the Kindle Dx?

Since the Kindle Dx can't go to a specific page, I've been splitting longer pdfs, with 1 file for 20-30 pages.

But if there's some way to get a Kindle-readable table of contents, or to get Kindle-readable bookmarks, then it might be an alternative.

Since the Kindle Dx can be slow on large pdfs, I've been compressing them. I can go to 150 DPI, but on the Mac, can't take the next step to 72 DPI without losing the text layer.

I thought about converting to epub and mobi, but there doesn't seem to be any practical way to convert regular scanned pdfs to epubs and mobis, without losing tables, and without corrupting numbers, etc. due to ocr errors.

P.S. I could also use some way to test pdfs for kindle compatibility before exporting them. Some don't open, and some do open but don't display as intended.

[shalym]

Originally Posted by MarjaE

So is there a better way to prep pdfs for the Kindle Dx?

Since the Kindle Dx can't go to a specific page, I've been splitting longer pdfs, with 1 file for 20-30 pages.

But if there's some way to get a Kindle-readable table of contents, or to get Kindle-readable bookmarks, then it might be an alternative.

Since the Kindle Dx can be slow on large pdfs, I've been compressing them. I can go to 150 DPI, but on the Mac, can't take the next step to 72 DPI without losing the text layer.

I thought about converting to epub and mobi, but there doesn't seem to be any practical way to convert regular scanned pdfs to epubs and mobis, without losing tables, and without corrupting numbers, etc. due to ocr errors.

Yes, if you have lots of tables in your books, then converting can be a problem. What kinds of books are you reading?

Shari

[MarjaE]

Originally Posted by shalym

Yes, if you have lots of tables in your books, then converting can be a problem. What kinds of books are you reading?

Shari

In pdf format? Most of the fiction is in epub format, and these don't need tables anyway. But a lot of reference books are only available in scanned pdf or djvu. And most roleplaying supplements are only available in prepared pdf.

Scanned pdfs usually have text issues. Prepared pdfs can have text issues with ligatures, and can have other issues due to layers, incompatible images, security, etc. The Kindle app for Mac can read these pdfs without the same problems as the Kindle Dx, so I can't use it to test files before sending to the Kindle Dx.