pdf2kobo

Overview

Convert your PDFs for easy reading on Kobo (and e-readers counterparts)

This shell script automates the steps needed for converting PDF files, thus any document originally in A4 portrait (or with maladjusted layout) will be readable in landscape mode, without any adjustment on the e-reader. And regardless of the origin of the document: ebook or web printing.

Introduction

Motivation

E-readers all offer a fantastic quality of reading compared to conventional computer screens and tablets. The Kobo, especially in its backlit HD version does not broke this rule.

However, when it comes to properly read a PDF file in A4 portrait, even large screens (typically 7 inches) are not enough, and it is necessary to double tap to zoom, scroll up or down the page, zoom out to change the page…​

Even the rotation of the document in landscape format does not completely solve the problem since one will still have to zoom and drag. In short these hassles spoil all the fun of having one’s library into his pocket.

Solution

Why not prepare their PDFs to enjoy reading before the transfer on the device?

This proposed shell script does the following:

1. creates two files. One with the upper part of a page and the other for the lower part.

2. assembles these two files into one. We then have double number of pages compared to the original, this will be equivalent to a 200% zoom.

3. to further maximize the display area, deletes margins.

4. finally turns the pages of -90° (a) to be in `landscape' mode.

(a) On the Kobo it is not possible to change the `action areas' to turn pages. This counterclockwise rotation allows to move forward in the document by clicking on the bottom of the screen, which seems more logical.

All these transformations are performed by the following tools:

• pdftocairo (up/down separation)

• pdftk (assembly of halves and rotation)

• briss (removal of margins)

Note that when the pages are cut in half, a slight overlap is expected. This will allow a line of text which has been cut in the middle to be repeated in the lower part of the page.

Installation

Main script

$ wget -O pdf2kobo https://raw.github.com/obarbeau/pdf2kobo/master/pdf2kobo.sh
$ chmod +x pdf2kobo
$ sudo mv pdf2kobo /usr/local/bin

External tools

To install the tools listed above, run the following command (Fedora):

yum install poppler-utils pdftk

For Briss, please follow the procedure on http://briss.sourceforge.net/ and set the BRISS_HOME variable in the main script on the directory choosen for installation.

Usage

pdf2kobo file-to-convert

Next steps

• Send the result directly to the Kobo if mounted under linux.

• Also accept .odt files, converting them to PDF first.

Known bugs

• If the final margin is very small, the text can be slightly cut on the left.

• ebooks with back covers might be problematic. In this case you must print the original document `in a file', with a standard A4 format, then use the script.

Licensing

This script is distributed under GPL v3. See LICENSE for details.