`makedjvu` — A simple Makefile script to produce a DjVu book from a set of page images

The script were tested with ScanTailor Advanced output, but will probably work with any other bilevel and mixed output too.

Для описания на русском языке обратитесь к README.rus.md.

Installation and requirements

Just download the Makefile and place it near the out/ directory containing the ScanTailor output images:

$ cd ~/MyLibrary/MyNewBook
$ ls
out/ MyNewBook.ScanTailor
$ wget https://github.com/pavrorov/makedjvu/blob/main/Makefile

You can also clone this repo and copy Makefile to the book folder:

$ git clone https://github.com/pavrorov/makedjvu.git
$ cd makedjvu
$ cp Makefile ~/MyLibrary/MyNewBook
$ cd ~/MyLibrary/MyNewBook

Requirements

In order to work, the script needs the following software to be installed:

GNU Coreutils (https://www.gnu.org/software/coreutils/coreutils.html).
GNU Make (https://www.gnu.org/software/make/).
ImageMagick (https://imagemagick.org/index.php).
Utils from the DjVuLibre project (http://djvu.sourceforge.net/).

Having that software installed, the following commands should be available on the system: make, tr, cat, sed, identify, convert, cjb2, c44, djvumake, djvuextract, djvm.

Usage

Basic usage

To produce the book DjVu file using the default options, just enter:

make

However, before stating the process it's better to overview it. make info will show you the brief description of what and how be produced:

$ make info
Book name: MyNewBook.djvu
Mixed pages: out/00-front.tif out/page-0002_1L.tif out/zz-back.tif
Cover pages: out/00-front.tif out/zz-back.tif
C44 options: (default)
CJB2 options: -lossy -clean
Mask threshold: 1%
Cover dpi: 100
Workdir: djvudir

First of all, the book DjVu file is named after the name of the folder the Makefile resides. Please note, however, that any spaces in the filename are substituted by _ in order to make the filename compatible with make.

Below the book filename there are lists of mixed (i.e. with illustrations) and cover pages. The cover pages, if any, are assumed to be the first and the last pages in out/ and only if they are color images. Bitonal covers are processed as any other pages.

After the list of special pages the command prints image processing parameters. For the set of c44 options see c44(1) manual page, and for cjb2 options, please, refer to the cjb2(1). The mask threshold value is the number used to extract the foreground layer from the mixed pages.

Please note, that the current version of the Makefile doesn't support ScanTailor's "split output" mode for mixed pages. Instead of that it uses the threshold filter to split the image of a mixed page onto foreground and background parts. The default threshold value of %1 for white seems to be enough because ScanTailor is known to make foreground parts completely black.

The next notable parameter is the DPI for cover pages. While the other (including the mixed ones) pages of the book are processed as are, the cover pages are downsampled by default. Why? Because from my point of view it isn't good to make the resulting DjVu file 3-5 times bigger than it could be just to have the covers included.

The last info line is the name of the working directory that is used to keep intermediate files.

Advanced usage

All the above and some additional parameters can be overridden on the command line. For instance, run:

make CJB2_OPTS="-losslevel 0"

to keep all bitonal material identical to TIFF images.

Another example: overriding the page directory and file suffixes:

make PAGESUF=.png PAGEDIR=pngdir

By the above command the script will look for PNG image files in the pngdir/ directory.

The complete list of currently supported options:

Option	Comment	Default value
`PAGEDIR`	Page image directory.	`out`
`PAGESUF`	Image file suffix (including the dot).	`.tif`
`C44`	Name (path) of `c44` command.	`c44`
`CJB2`	Name (path) of `cjb2` command.	`cjb2`
`CONVERT`	Name (path) of `convert` command.	`convert`
`IDENTIFY`	Name (path) of `identify` command.	`identify`
`DJVUMAKE`	Name (path) of `djvumake` command.	`djvumake`
`DJVUEXTRACT`	Name (path) of `djvuextract` command.	`djvuextract`
`DJVM`	Name (path) of `djvm` command.	`djvm`
`C44_OPTS`	Options for `c44` command.	(no options)
`CJB2_OPTS`	Options for `cjb2` command.	`-lossy -clean`
`THRESHOLD`	White threshold value for mixed page separation.	1%
`COVER_DPI`	DPI to downsample cover images to.	100
`NAME`	Book base name.	After the name of the current folder with spaces substituted by `_`.
`FILENAME`	Book file name.	`NAME` + `.djvu`
`WORKDIR`	Name of the directory for intermediate files.	`djvudir`

License

makedjvu — produce a DjVu book from a set of page images.

This program is free software: you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation, either version 3 of the License, or (at your option) any later version.

This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details.

You should have received a copy of the GNU General Public License along with this program. If not, see https://www.gnu.org/licenses/.

pavrorov/makedjvu