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Willus.com's K2pdfopt
 
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v2.34b
21 Mar 2016

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(Windows, Linux, OSX)

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(GUIs; Native Kindle PDF Viewer)

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OVERVIEW
K2pdfopt optimizes PDF/DJVU files for mobile e-readers (e.g. the Kindle) and smartphones. It works well on multi-column PDF/DJVU files and can re-flow text even on scanned PDF files. It can also be used as a general PDF copying/cropping/re-sizing/OCR-ing manipulation tool. It can generate native or bitmapped PDF output, with an optional OCR layer. There are downloads for MS Windows, Mac OSX, and Linux. The MS Windows version has an integrated GUI. K2pdfopt is open source. Here's a quick example (click on the images below to get the PDF files):
IT TURNS THIS . . .

(8.5 x 11 PDF or DJVU file)
   . . . INTO THIS.

(6-inch reader screen)
     . . . OR THIS.

(4-inch smartphone screen)


 
MS Windows integrated GUI front-end


Unsolicited comments from k2pdfopt users (refresh the page to change the comments):

         "I wanted thank you for your really great software. I was this close to return my kindle back, since I mostly deal with PDF files, and I couldn't find a way to deal with them." -- September 8, 2014         

         "...many thanks for your wonderful tool for making kindle friendly pdf from 2 column pdfs which are quite common in research literature!" -- November 21, 2013         

LATEST NEWS
21 Mar 2016    K2pdfopt v2.34b released. This release fixes two more MS Windows bugs. The Linux and Mac versions are not affected (still v2.34a).
20 Mar 2016    Updated mupdf_mod/string.c in the v2.34 source archive. It was not the correct version.
19 Mar 2016    K2pdfopt v2.34a released. This release fixes a couple more bugs, including a critical GUI issue which did not allow editing of the "Additional Options" entry.
18 Mar 2016    K2pdfopt v2.34 released. This release adds some feature requests and bug fixes from the past few months, including the ability to select the font size of the converted document and the selection of an output folder in the MS Windows GUI. See all of the other new features, improvements and bug fixes in the k2pdfopt version history.
3 Oct 2015    K2pdfopt v2.33a released. This release fixes a bug in the MS Windows GUI--the preview page selection control went missing in v2.33. So much for my GUI regression testing.
27 Sep 2015    K2pdfopt v2.33 released. This release adds some feature requests and bug fixes from the past few months. In the MS Windows GUI, I've added the ability to select multiple crop boxes. See all of the other new features, improvements and numerous bug fixes in the k2pdfopt version history.
6 Mar 2015    K2pdfopt v2.32 released. This release adds a feature I've long wanted to implement in the MS Windows GUI--graphical selection of the crop margins. See all of the other new features, improvements and numerous bug fixes in the k2pdfopt version history.
23 Jan 2015    K2pdfopt was used by the JSTOR folks as part of their participation in the NYPL Open E-book Hackathon.
[... more news]


ABOUT K2PDFOPT (MORE DETAIL)
K2pdfopt (Kindle 2 PDF Optimizer) is a stand-alone program which optimizes the format of PDF (or DJVU) files for viewing on small (e.g. 6-inch) mobile reader and smartphone screens such as the Kindle's. The output from k2pdfopt is a new (optimized) PDF file. K2pdfopt is meant for text-based files on a white background which may also have graphics or figures, and it works equally well on native and/or scanned or bitmapped PDF or DJVU files. It is fully automated and can batch-process PDF/DJVU files. K2pdfopt works by converting each page of the PDF/DJVU file to a bitmap and then scanning the bitmap for viewable areas (rectangular regions) and cutting and cropping these regions and assembling them into multiple smaller pages without excess margins so that the viewing region is maximized. Making use of this method, k2pdfopt can re-flow text lines, even on scanned documents (see the Winnie the Pooh example below). You can see another example of how k2pdfopt works on this help page.

As of v1.50, k2pdfopt will also embed OCR text into the PDF so that text can be searched and highlighted, and v1.60 can create output files with the native PDF instructions from the source file (if the source file is PDF). Any kind of PDF/DJVU file (best if it has a primarily white background) can be converted. K2pdfopt works especially well on two-column or multi-column PDF/DJVU files such as IEEE and other technical journal articles (see examples below--it auto-detects two-column regions on the page), but even single-column files will often be significantly improved and much easier to read (see examples). K2pdfopt has the advantage over other PDF converters in that it fully preserves the rendered PDF fonts and graphics from the original file, unlike programs that convert the PDF to an e-book format. Also, because k2pdfopt is completely independent of language or fonts, it will work equally well on documents in any language.


HOW TO USE K2PDFOPT
   No install is required and no extra files or packages are necessary to run k2pdfopt. Just drag and drop your PDF/DJVU file icon onto the k2pdfopt icon to convert it. You will be prompted for conversion options (as of v1.16). Press <Enter> to convert the file using the default settings. A new PDF file with _k2opt at the end of the name will be created. The output file is optimized for viewing on Kindles and other mobile readers with 6-inch screens (if the settings are not customized). Or drop a folder full of PDF/DJVU files onto the k2pdfopt icon to batch process. You can even drop a folder full of bitmap images to have them converted into a single PDF as if they were pages of a PDF file.

See my k2pdfopt help page for more detailed help.

Note that if you have a Kindle 2, it must have the latest firmware that allows it to view native PDF files.

EXAMPLES (click on images to get PDF file)
Example Type Original
File
Optimized
for Kindle

(default settings)
Optimized
for Smartphone

(-odpi 250)
Four-column:
(must use -col 4)

(must use -col 4)
Scanned pages
Two-column #2:
One-column

K2PDFOPT REVIEWS / BLOGS / FORUMS / TWEETS
    3-18-16    epubor.com (nice tutorial)
    7-10-15    blog.the-ebook-reader.com
    6-14-15    MacWorld.co.uk
    7-22-14    VidaSemPapel.com.br (In Portuguese)
    6-20-14    ghacks.net
    4-11-14    betanews.com
    4-11-14    TrishTech.com
    3-14-14    Dr. Simon Bance
    1-28-13    Intelligent Rumblings
    1-7-13    Net Buffalo (In Japanese)
    12-1-12    blog.trufanov.com (In Russian)
    11-4-12    abstractmodem.com (archived)
    9-20-12    ozgurlukicin.org (in Turkish)
    6-27-12    equiscentrico.com (in Spanish)
    6-26-12    ketabkhan.info (in Persian)
    1-4-12    TechLogon.com
    11-9-11    Świat Czytników (in Polish)
    11-5-11    tivasyk.info (in Ukrainian)
    11-1-11    WMLCloud.com
   
    10-31-11    linospapa.blogspot.com (in Greek)
    10-27-11    Steve Gibson's Security Now #324
    10-21-11    addictivetips.com
    10-12-11    Paper4Kindle (in Chinese)
    (varies)    mobileread.com forums
    9-7-11    habrahabr.ru (in Russian)
    8-4-11    steepbend.ru (in Russian)
    8-3-11    ssnjara.wordpress.com (in Croatian)
    8-2-11    howtogeek.com (note comments from "willus")
    7-30-11    artiss.co.uk
    7-30-11    ideasfor.info (in Russian)
    7-27-11    guidingtech.com (note comments from "willus")
    7-22-11    blog.rgub.ru (in Russian)
    7-22-11    aldus2006.typepad.fr (in French)
    7-22-11    korben.info (in French)
    7-21-11    lifehacker.ru (in Russian)
    7-20-11    redferret.net
    7-19-11    freewaregenius.com (full review)

OTHER PDF/CONVERTING SOFTWARE
See my page on PDF Conversion Tips.

RECOMMENDED WINDOWS PDF/E-BOOK READER: SUMATRA
This is my plug for Krzysztof Kowalczyk's Sumatra PDF reader: a small, efficient, yet feature-rich open-source PDF reader that does everything I want. Sumatra also displays several file types other than PDF, including XPS, DJVU, CBZ, CBR, and PS/EPS (PS/EPS requires Ghostscript), EPUB, and MOBI. It is a refreshing alternative to Adobe's bloatware. I highly recommend it.

This page last modified
Saturday, 09-Apr-2016 08:49:02 MDT