Fixing slow PDFs

PF4Mobile · 09-21-2011, 06:56 PM

Hi all

I was wondering if any of you who are complaining about Onyx Boox 90 being slow with some PDFs has tried to fix the pdf by:

splitting the PDF in smaller docs

optimizing the PDF -Adobe Acrobat and others like it can do various things with PDF files.

There are a couple of PDF formats and I was wondering if you guys would like to start experimenting with different formats. I do not have the device but I am willing to help with converting between PDF formats (where possible) and with optimizing PDFs

A possible clue why some PDFs are slow when loaded, can be found here

There are two layouts to the PDF files—non-linear (not "optimized") and linear ("optimized"). Non-linear PDF files consume less disk space than their linear counterparts, though they are slower to access because portions of the data required to assemble pages of the document are scattered throughout the PDF file. Linear PDF files (also called "optimized" or "web optimized" PDF files) are constructed in a manner that enables them to be read in a Web browser plugin without waiting for the entire file to download, since they are written to disk in a linear (as in page order) fashion.[10] PDF files may be optimized using Adobe Acrobat software or QPDF.

I believe that linearity might be a cause for slower loading in your case too, I believe that the PDF viewer that Onyx implemented might be affected by this although it is not a browser.

Please either post PDFs that are giving you hard time or let't get in touch and send me the files. Alternatively you can upload them on file sharing servers and post the link here. This last method will have the advantage of allowing all Onyx owners to try the file.
Let't work together on this!

Thanks
PF

PS: for an introduction in PDF formats please read this:
http://en.wikipedia.org/wiki/Portable_Document_Format

jian1 · 09-25-2011, 03:04 AM

Well...linearizing PDF doesn't solve the slow issue.

I have tried qpdf under linux and linearized most of my non-linear PDFs, the result: same slowiness.

PF4Mobile · 09-25-2011, 10:07 AM

Quote:

Originally Posted by jian1

Well...linearizing PDF doesn't solve the slow issue.

I have tried qpdf under linux and linearized most of my non-linear PDFs, the result: same slowiness.

Good to know. thnaks for trying and getting back to the community
How about splitting the initial PDF in smaller ones?

Elfwreck · 09-25-2011, 10:39 AM

I don't have a Boox, but I run across slow PDFs with my PEZ sometimes. I find it helps to leave that book, open something else, change the page, and then go back to the other book--apparently the memory gets "full" or something like that? (I regularly convert 150k+ words fanfic novels to PDFs sized for 6" screens, so I get 1500 page PDFs.)

Splitting into smaller units should help. I don't get this on "normal" small PDFs. I've gotten weird slowdowns on some PDFs that are text-under-image productions, like those from Wowio.com, that have a weird metadata lock on them. To fully edit them, I have to remove the standard lock and then use BeCyPDFMetaEdit -- not Acrobat -- to remove all metadata, before I can edit the title/author fields. *Those* PDFs are prone to being slow to load, because there's an image of each page on top of the (invisible) text.

09-21-2011, 06:56 PM	#1
PF4Mobile Guru Posts: 629 Karma: 3526 Join Date: Jun 2011 Device: Kobo Touch, Nook Touch, EEE 800 Note, Entourage PE, finally M92	Fixing slow PDFs Hi all I was wondering if any of you who are complaining about Onyx Boox 90 being slow with some PDFs has tried to fix the pdf by: splitting the PDF in smaller docs optimizing the PDF -Adobe Acrobat and others like it can do various things with PDF files. There are a couple of PDF formats and I was wondering if you guys would like to start experimenting with different formats. I do not have the device but I am willing to help with converting between PDF formats (where possible) and with optimizing PDFs A possible clue why some PDFs are slow when loaded, can be found here There are two layouts to the PDF files—non-linear (not "optimized") and linear ("optimized"). Non-linear PDF files consume less disk space than their linear counterparts, though they are slower to access because portions of the data required to assemble pages of the document are scattered throughout the PDF file. Linear PDF files (also called "optimized" or "web optimized" PDF files) are constructed in a manner that enables them to be read in a Web browser plugin without waiting for the entire file to download, since they are written to disk in a linear (as in page order) fashion.[10] PDF files may be optimized using Adobe Acrobat software or QPDF. I believe that linearity might be a cause for slower loading in your case too, I believe that the PDF viewer that Onyx implemented might be affected by this although it is not a browser. Please either post PDFs that are giving you hard time or let't get in touch and send me the files. Alternatively you can upload them on file sharing servers and post the link here. This last method will have the advantage of allowing all Onyx owners to try the file. Let't work together on this! Thanks PF PS: for an introduction in PDF formats please read this: http://en.wikipedia.org/wiki/Portable_Document_Format Last edited by PF4Mobile; 10-02-2011 at 08:43 AM.

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09-25-2011, 03:04 AM	#2
jian1 Banned Posts: 140 Karma: 5766 Join Date: Jan 2011 Device: Onyx Boox M92	Well...linearizing PDF doesn't solve the slow issue. I have tried qpdf under linux and linearized most of my non-linear PDFs, the result: same slowiness.

09-25-2011, 10:39 AM	#4
Elfwreck Grand Sorcerer Posts: 5,185 Karma: 25133758 Join Date: Nov 2008 Location: SF Bay Area, California, USA Device: Pocketbook Touch HD3 (Past: Kobo Mini, PEZ, PRS-505, Clié)	I don't have a Boox, but I run across slow PDFs with my PEZ sometimes. I find it helps to leave that book, open something else, change the page, and then go back to the other book--apparently the memory gets "full" or something like that? (I regularly convert 150k+ words fanfic novels to PDFs sized for 6" screens, so I get 1500 page PDFs.) Splitting into smaller units should help. I don't get this on "normal" small PDFs. I've gotten weird slowdowns on some PDFs that are text-under-image productions, like those from Wowio.com, that have a weird metadata lock on them. To fully edit them, I have to remove the standard lock and then use BeCyPDFMetaEdit -- not Acrobat -- to remove all metadata, before I can edit the title/author fields. Those PDFs are prone to being slow to load, because there's an image of each page on top of the (invisible) text.