k2pdfopt: optimizes PDFs for viewing on e-readers

[GOODMAN]

dear Willus
i am using windows xp 32 bit.
when i try to load batch of pdf files the application crashes after processing first file especially in native pdf output. can u fix it?

[willus]

Originally Posted by GOODMAN

...when i try to load batch of pdf files the application crashes after processing first file especially in native pdf output...

I've re-produced this error. I'll fix it in the next release. Thanks for letting me know.

[CK2go]

Hi Willus,

first I'd like to thank you for this great tool. Wouldn't be possible to read scientific papers on the Kindle in such a comfortable way without k2pdfopt. Thanks!

I've got a question on native PDF output and text reflow...

In the command line documentation it says:

1. Native PDF output cannot be used with text wrapping
   on (see -wrap option).  Turning it on will disable
   text wrapping.

So I guess it is not possible now to reflow/wrap the text.

Will it be possible in the future? I'm asking, as the native PDFs have much smoother fonts and therefore are much nicer to read, but as they still have the same number of word's per line, esp. single column documents become hard to read due to small font size...

Thanks a lot,
Carsten

[willus]

Originally Posted by CK2go

Will it be possible [to use text re-flow and native PDF output together] in the future? I'm asking, as the native PDFs have much smoother fonts and therefore are much nicer to read, but as they still have the same number of word's per line, esp. single column documents become hard to read due to small font size...

You wouldn't like the result using them together--trust me. It would take too long to render the PDF page and probably run your device out of memory, and selecting text would not work well. But if you don't mind a larger output file size, you can get an arbitrarily smooth font in the re-flow conversion by increasing the output file resolution. See the 4th question on my FAQ page. Also turn on OCR if you want to be able to search for or select the text.

[CK2go]

Thanks for te fast answer. Will try the higher resolution then...

[gadd]

hi willus,

thank you once again for such a terrific program.

i am having difficulty to convert a scanned two page in a row file into k2opt format. i have tried -ocr command but the result was ineffective. which command lines would you suggest to get a solid version of this pdf for kindle device?

p.s. i attach those files to the post.

[rostamiani]

I converted a document using -n -dev kpw for kindle paperwhite and is tooooo slow on kindle + Low Memory crash !!!

This is the file :
http://www.4shared.com/office/xcmp4h...ses_k2opt.html

[willus]

Originally Posted by rostamiani

I converted a document using -n -dev kpw for kindle paperwhite and is tooooo slow on kindle + Low Memory crash !!!

This is the file :
http://www.4shared.com/office/xcmp4h...ses_k2opt.html

Can you post the source document?

[willus]

Originally Posted by gadd

i am having difficulty to convert a scanned two page in a row file into k2opt format. i have tried -ocr command but the result was ineffective. which command lines would you suggest to get a solid version of this pdf for kindle device?

p.s. i attach those files to the post.

This is a tough one because the scan isn't great quality. Try both the commands below in succession. (I've re-named your file to be more manageable on the command-line):

k2pdfopt -mode copy -n -grid 2x1x1.5 -w 1t -h 1t century20.pdf -o temp.pdf

k2pdfopt -dev kpw -as temp.pdf -m 0.4,0.2,0.4,0.2 -de 1.5 -gtr .015 -o century20_k2pdfopt.pdf

The first command splits the book into a one-page-per-page temp file so that each page can be auto-straightened. The second command processes the new temp file to create the final output. If you want to turn on OCR, Tesseract does a decent job of OCR-ing the temp file if you have it installed. Just add -ocr to the second command. Here's what some of the other options do (a complete list of command-line options is here):

-dev kpw sets for paperwhite. You can leave that off if you have an older kindle.

-as will auto-straighten each page, which will help k2pdfopt break up the rows correctly.

-m 0.4,0.2,0.4,0.2 will ignore 0.4 inches on the sides and 0.2 inches on the top and bottom of the temp file. This will chop off some of the unwanted marks in the margins that are keeping k2pdfopt from re-flowing the document correctly.

-de 1.5 sets the defect size to 1.5 points so that little marks that are up to 1.5 points in size will be ignored (the scan quality is poor and you have lots of these).

-gtr 0.015 will make k2pdfopt a little more aggressive than normal in breaking lines of text since some of them are pretty close together.

Of course, you can try adjusting any or all of the options above--I only had four pages of your book to work with, so they might no be tuned quite correctly. I wasn't able to get a perfect result, but it's an improvement over what you got, I think.

[rostamiani]

Originally Posted by willus

Can you post the source document?

Its not about this document, All of my documents cause kindle to stop and restart !!!
This is the source file :

http://www.4shared.com/office/GGuGXW...e_Atlases.html

[willus]

Originally Posted by rostamiani

Its not about this document, All of my documents cause kindle to stop and restart !!!
This is the source file :

http://www.4shared.com/office/GGuGXW...e_Atlases.html

Have you looked through my native output help page (with video demonstration)? Using one of the -mode options will probably solve your issue.

[dgvirtual]

I am having problem dealing with superscript (footnote references) in files.

Here is the original pdf, that has reference 60 in the second paragraph: https://dl.dropbox.com/u/4047484/superscript-input.pdf

And here is the output file with pretty much default options used: https://dl.dropbox.com/u/4047484/superscript-output.pdf

As you can see, the superscript causes two lines not to be treated as separate lines of text...

Is there a way to deal with this problem?

[willus]

Originally Posted by dgvirtual

I am having problem dealing with superscript (footnote references) in files.

Here is the original pdf, that has reference 60 in the second paragraph: https://dl.dropbox.com/u/4047484/superscript-input.pdf

And here is the output file with pretty much default options used: https://dl.dropbox.com/u/4047484/superscript-output.pdf

As you can see, the superscript causes two lines not to be treated as separate lines of text...

Is there a way to deal with this problem?

Yes--use a larger value for the -gtr option (default is 0.006). This worked with your particular example:

k2pdfopt -gtr 0.03 superscript-input.pdf

This makes k2pdfopt more aggressive about breaking apart lines of text, but potentially at the expense of inadvertently breaking apart figures. For more on options, see my help page with the command-line options.

[dgvirtual]

Originally Posted by willus

Yes--use a larger value for the -gtr option (default is 0.006). This worked with your particular example:

k2pdfopt -gtr 0.03 superscript-input.pdf

This makes k2pdfopt more aggressive about breaking apart lines of text, but potentially at the expense of inadvertently breaking apart figures. For more on options, see my help page with the command-line options.

Thanks, it did work, but also it broke both graphs ant tables in the paper... Oh well, one cannot have it all...

I guess, there is no easy way to make the program treat different pages using different settings, unless I want to do conversion page by page, joining the document afterwards?

[dgvirtual]

What could optimization settings for Kobo Glo look like?

it has screen of 122mm x 90,3mm, screen size in pixels is 1024x768. I tried kindle paperwhite settings (-dev kpw) but those do not procude an image that could be used without further fitting (I use vertical fitting, and then I can see the whole page and turn it without scrolling).

Besides, Kobo Glo has the page count bar at the bottom which is 9,3 mm high.

Would it be possible to add Kobo Glo as a -dev preset?