Provided by: gscan2pdf_1.2.3-1_all 
Name
gscan2pdf - A GUI to produce PDFs or DjVus from scanned documents
Synopsis
1. Scan one or several pages in with File/Scan
2. Create PDF of selected pages with File/Save
Description
gscan2pdf has the following command-line options:
--device=<device> Specifies the device to use, instead of getting the list of devices from
via the SANE API. This can be useful if the scanner is on a remote computer which is not
broadcasting its existence.
--help Displays this help page and exits.
--log=<log file> Specifies a file to store logging messages.
--(debug|info|warn|error|fatal) Defines the log level. If a log file is specified, this
defaults to 'debug', otherwise 'warn'.
--version Displays the program version and exits.
Scanning is handled with SANE via scanimage. PDF conversion is done by PDF::API2. TIFF
export is handled by libtiff (faster and smaller memory footprint for multipage files).
Download
gscan2pdf is available on Sourceforge
(<http://sourceforge.net/projects/gscan2pdf/files/gscan2pdf/>).
Debian-based
If you are using Debian, you should find that sid has the latest version already packaged.
If you are using a Ubuntu-based system, you can automatically keep up to date with the
latest version via the ppa:
"sudo apt-add-repository ppa:jeffreyratcliffe/ppa"
If you are you are using Synaptic, then use menu Edit/Reload Package Information, search
for gscan2pdf in the package list, and lo and behold, you can install the nice shiny new
version.
From the command line:
"sudo apt-get update"
"sudo apt-get install gscan2pdf"
RPMs
Download the rpm from Sourceforge, and then install it with "rpm -i gscan2pdf-version.rpm"
From source
The source is hosted in the files section of the gscan2pdf project on Sourceforge
(<http://sourceforge.net/projects/gscan2pdf/files/>).
From the repository
gscan2pdf uses Git for its Revision Control System. You can browse the tree at
<http://sourceforge.net/p/gscan2pdf/code/>.
Git users can clone the complete tree with "git clone
git://git.code.sf.net/p/gscan2pdf/code"
Building gscan2pdf from source
Having downloaded the source either from a Sourceforge file release, or from the Git
repository, unpack it if necessary with "tar xvfz gscan2pdf-x.x.x.tar.gz cd
gscan2pdf-x.x.x"
"perl Makefile.PL", will create the Makefile. There is a "make test", but this is not
machine-dependent, and therefore really just for my benefit to make sure I haven't broken
the device-dependent options parsing routine.
You can install directly from the source with "make install", but building the appropriate
package for your distribution should be as straightforward as "make debdist" or "make
rpmdist". However, you will additionally need the rpm, devscripts, fakeroot, debhelper and
gettext packages.
Dependencies
The list below looks daunting, but all packages are available from any reasonable up-to-
date distribution. If you are using Synaptic, having installed gscan2pdf, locate the
gscan2pdf entry in Synaptic, right-click it and you can install them under Recommends.
Note also that the library names given below are the Debian/Ubuntu ones. Those
distributions using RPM typically use perl(module) where Debian has libmodule-perl.
Required
libgtk2.0-0 (>= 2.4)
The GTK+ graphical user interface library.
libglib-perl (>= 1.100-1)
Perl interface to the GLib and GObject libraries
libgtk2-perl (>= 1:1.043-1)
Perl interface to the 2.x series of the Gimp Toolkit library
libgtk2-imageview-perl
Perl bindings to the gtkimageview widget. See
<http://trac.bjourne.webfactional.com/>
libgtk2-ex-simple-list-perl
A simple interface to Gtk2's complex MVC list widget
liblocale-gettext-perl (>= 1.05)
Using libc functions for internationalization in Perl
libpdf-api2-perl
provides the functions for creating PDF documents in Perl
libsane
API library for scanners
libsane-perl
Perl bindings for libsane.
libset-intspan-perl
manages sets of integers
libtiff-tools
TIFF manipulation and conversion tools
Imagemagick
Image manipulation programs
perlmagick
A perl interface to the libMagick graphics routines
sane-utils
API library for scanners -- utilities.
Optional
sane
scanner graphical frontends. Only required for the scanadf frontend.
libgtk2-ex-podviewer-perl
Perl Gtk2 widget for displaying Plain Old Documentation (POD). Not required if you
don't need the gscan2pdf documentation (which is anyway repeated on the website).
unpaper
post-processing tool for scanned pages. See <http://unpaper.berlios.de/>.
xdg-utils
Desktop integration utilities from freedesktop.org. Required for Email as PDF.
See <http://portland.freedesktop.org/wiki/>
djvulibre-bin
Utilities for the DjVu image format. See <http://djvu.sourceforge.net/>
gocr
A command line OCR. See <http://jocr.sourceforge.net/>.
tesseract
A command line OCR. See <http://code.google.com/p/tesseract-ocr/>
ocropus
A command line OCR. See <http://code.google.com/p/ocropus/>
cuneiform
A command line OCR. See <http://launchpad.net/cuneiform-linux>
Support
There are two mailing lists for gscan2pdf:
gscan2pdf-announce
A low-traffic list for announcements, mostly of new releases. You can subscribe at
<http://lists.sourceforge.net/lists/listinfo/gscan2pdf-announce>
gscan2pdf-help
General support, questions, etc.. You can subscribe at
<http://lists.sourceforge.net/lists/listinfo/gscan2pdf-help>
Reporting bugs
Before reporting bugs, please read the "FAQs" section.
Please report any bugs found, preferably against the Debian package[1][2]. You do not
need to be a Debian user, or set up an account to do this.
1. http://packages.debian.org/sid/gscan2pdf
2. http://www.debian.org/Bugs/
Alternatively, there is a bug tracker for the gscan2pdf project on Sourceforge
(<http://sourceforge.net/p/gscan2pdf/_list/tickets?source=navbar>).
Please include the log file created by "gscan2pdf --log=log" with any new bug report.
Translations
gscan2pdf has already been partly translated several languages. If you would like to
contribute to an existing or new translation, please check out Rosetta:
<https://translations.launchpad.net/gscan2pdf>
Note that the translations for the scanner options are taken directly from sane-backends.
If you would like to contribute to these, you can do so either at contact the sane-devel
mailing list (sane-devel@lists.alioth.debian.org) and have a look at the po/ directory in
the source code <http://www.sane-project.org/cvs.html>.
Alternatively, Ubuntu has its own translation project. For the 9.04 release, the
translations are available at
<https://translations.launchpad.net/ubuntu/jaunty/+source/sane-backends/+pots/sane-backends>
Menus
File
New
Clears the page list.
Open
Opens any format that imagemagick supports. PDFs will have their embedded images extracted
and imported one per page.
Scan
Sets options before scanning via SANE.
Device
Chooses between available scanners.
# Pages
Selects the number of pages, or all pages to scan.
Source document
Selects between single sided or double sides pages.
This affects the page numbering. Single sided scans are numbered consecutively. Double
sided scans are incremented (or decremented, see below) by 2, i.e. 1, 3, 5, etc..
Side to scan
If double sided is selected above, assuming a non-duplex scanner, i.e. a scanner that
cannot automatically scan both sides of a page, this determines whether the page number is
incremented or decremented by 2.
To scan both sides of three pages, i.e. 6 sides:
1. Select:
# Pages = 3 (or "all" if your scanner can detect when it is out of paper)
Double sided
Facing side
2. Scans sides 1, 3 & 5.
3. Put pile back with scanner ready to scan back of last page.
4. Select:
# Pages = 3 (or "all" if your scanner can detect when it is out of paper)
Double sided
Reverse side
5. Scans sides 6, 4 & 2.
6. gscan2pdf automatically sorts the pages so that they appear in the correct order.
Device-dependent options
These, naturally, depend on your scanner. They can include
Page size.
Mode (colour/black & white/greyscale)
Resolution (in PPI)
Batch-scan
Guarantees that a "no documents" condition will be returned after the last scanned
page, to prevent endless flatbed scans after a batch scan.
Wait-for-button/Button-wait
After sending the scan command, wait until the button on the scanner is pressed before
actually starting the scan process.
Source
Selects the document source. Possible options can include Flatbed or ADF. On some
scanners, this is the only way of generating an out-of-documents signal.
Save
Saves the selected or all pages as a PDF, DjVu, TIFF, PNG, JPEG, PNM or GIF.
PDF Metadata
Metadata are information that are not visible when viewing the PDF, but are embedded in
the file and so searchable and can be examined, typically with the "Properties" option of
the PDF viewer.
The metadata are completely optional, but can also be used to generate the filename see
preferences for details.
DjVu
Both black and white, and colour images produce better compression than PDF. See
<http://www.djvuzone.org/> for more details.
Email as PDF
Attaches the selected or all pages as a PDF to a blank email. This requires xdg-email,
which is in the xdg-utils package. If this is not present, the option is ghosted out.
Print
Prints the selected or all pages.
Compress temporary files
If your temporary ($TMPDIR) directory is getting full, this function can be useful -
compressing all images at LZW-compressed TIFFs. These require much less space than the PNM
files that are typically produced by SANE or by importing a PDF.
Edit
Delete
Deletes the selected page.
Renumber
Renumbers the pages from 1..n.
Note that the page order can also be changed by drag and drop in the thumbnail view.
Select
The select menus can be used to select, all, even, odd, blank, dark or modified pages.
Selecting blank or dark pages runs imagemagick to make the decision. Selecting modified
pages selects those which have modified by threshold, unsharp, etc., since the last OCR
run was made.
Preferences
The preferences menu item allows the control of the default behviour of various functions.
Most of these are self-explanatory.
Frontend
gscan2pdf supports two frontends, scanimage and scanadf. scanadf support was added when
it was realised that scanadf works better than scanimage with some scanners. On Debian-
based systems, scanadf is in the sane package, not, like scanimage, in sane-utils. If
scanadf is not present, the option is obviously ghosted out.
In 0.9.27, Perl bindings for SANE were introduced and two further frontends, scanimage-
perl and scanadf-perl (scanimage and scanadf transliterated from C into Perl) were added.
Before 1.2.0, options available through CLI frontends like scanimage were made visible as
users asked for them. In 1.2.0, all options can be shown or hidden via Edit/Preferences,
along with the ability to specify which options trigger a reload.
Default filename for PDF files
The following variables are available, which are replaced by the corresponding metadata:
%a author
%t title
%y document's year
%Y today's year
%m document's month
%M today's month
%d document's day
%D today's day
View
Zoom 100%
Zooms to 1:1. How this appears depends on the desktop resolution.
Zoom to fit
Scales the view such that all the page is visible.
Zoom in
Zoom out
Rotate 90 clockwise
The rotate options require the package imagemagick and, if this is not present, are
ghosted out.
Rotate 180
Rotate 90 anticlockwise
Tools
Threshold
Changes all pixels darker than the given value to black; all others become white.
Unsharp mask
The unsharp option sharpens an image. The image is convolved with a Gaussian operator of
the given radius and standard deviation (sigma). For reasonable results, radius should be
larger than sigma. Use a radius of 0 to have the method select a suitable radius.
Crop
unpaper
unpaper (see <http://unpaper.berlios.de/>) is a utility for cleaning up a scan.
OCR (Optical Character Recognition)
The gocr, tesseract, ocropus or cuneiform utilities are used to produce text from an
image.
There is an OCR output buffer for each page and is embedded as plain text behind the
scanned image in the PDF produced. This way, Beagle can index (i.e. search) the plain
text.
In DjVu files, the OCR output buffer is embedded in the hidden text layer. Thus these can
also be indexed by Beagle.
There is an interesting review of OCR software at
<http://web.archive.org/web/20080529012847/http://groundstate.ca/ocr>. An important
conclusion was that 400ppi is necessary for decent results.
Up to v2.04, the only way to tell which languages were available to tesseract was to look
for the language files. Therefore, gscan2pdf checks the path returned by:
tesseract '' '' -l ''
If there are no language files in the above location, then gscan2pdf assumes that
tesseract v1.0 is installed, which had no language files.
Variables for user-defined tools
The following variables are available:
%i input filename
%o output filename
%r resolution
An image can be modified in-place by just specifying %i.
FAQs
Why isn't option xyz available in the scan window?
Possibly because SANE or your scanner doesn't support it.
If an option listed in the output of "scanimage --help" that you would like to use isn't
available, send me the output and I will look at implementing it.
I've only got an old flatbed scanner with no automatic sheetfeeder. How do I scan a multipage
document?
If you are lucky, you have an option like Wait-for-button or Button-wait, where the
scanner will wait for you to press the scan button on the device before it starts the
scan, allowing you to scan multiple pages without touching the computer.
Otherwise, you have to set the number of pages to scan to 1 and hit the scan button on the
scan window for each page.
Why is option xyz ghosted out?
Probably because the package required for that option is not installed. Email as PDF
requires xdg-email (xdg-utils), unpaper and the rotate options require imagemagick.
Why can I not scan from the flatbed of my HP scanner?
Generally for HP scanners with an ADF, to scan from the flatbed, you should set "# Pages"
to "1", and possibly "Batch scan" to "No".
When I update gscan2pdf using the Update Manager in Ubuntu, why is the list of changes never
displayed?
As far as I can tell, this is pulled from changelogs.ubuntu.com, and therefore only the
changelogs from official Ubuntu builds are displayed.
Why can gscan2pdf not find my scanner?
If your scanner is not connected directly to the machine on which you are running
gscan2pdf and you have not installed the SANE daemon, saned, gscan2pdf cannot
automatically find it. In this case, you can specify the scanner device on the command
line:
"gscan2pdf --device <device">
How can I search for text in the OCR layer of the finished PDF or DJVU file?
pdftotext or djvutxt can extract the text layer from PDF or DJVU files. See the respective
man pages for details.
Having opened a PDF or DJVU file in evince or Acrobat Reader, the search function will
typically find the page with the requested text and highlight it.
There are various tools for searching or indexing files, including PDF and DJVU:
• (meta) Tracker (<https://projects.gnome.org/tracker/>)
• plone (<http://plone.org/>)
• pdfgrep (<http://pdfgrep.sourceforge.net/>
• swish-e (<http://www.swish-e.org/>)
• recoll (<http://www.lesbonscomptes.com/recoll/>)
• terrier (<http://www.lesbonscomptes.com/recoll/>)
See Also
Xsane
http://scantailor.sourceforge.net/
Author
Jeffrey Ratcliffe (ra28145 at users dot sf dot net)
Thanks to
• all the people who have sent patches, translations, bugs and feedback.
• the GTK2 project for a most excellent graphics toolkit.
• the Gtk2-Perl project for their superb Perl bindings for GTK2.
• The SANE project for scanner access
• Bjoern Lindqvist for the gtkimageview widget
• Sourceforge for hosting the project.