GSCAN2PDF(1) User Contributed Perl Documentation GSCAN2PDF(1)Namegscan2pdf - A GUI to produce a multipage PDF or DjVu from a scan.
Synopsis
1. Scan one or several pages in with File/Scan
2. Create PDF of selected pages with File/Save
Description
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).
Downloadgscan2pdf is available on Sourceforge
(<https://sourceforge.net/project/showfiles.php?group_id=174140&package_id=199621>).
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, just add the following line to
your "/etc/apt/sources.list" file:
"deb http://ppa.launchpad.net/jeffreyratcliffe/ubuntu <release> main"
"deb-src http://ppa.launchpad.net/jeffreyratcliffe/ubuntu <release>
main"
where "<release>" is the version of Ubuntu you are using.
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 automatically.
From the command line:
"apt-get update"
"apt-get install gscan2pdf"
If you add my key to your list of trusted keys, then you will no longer
get the "not authenticated" warnings. Fetch the key:
"gpg --keyserver subkeys.pgp.net --recv-keys 4DD7CC93"
Then add it to the apt keyring:
"gpg --export --armor 4DD7CC93 | sudo apt-key add -"
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/project/showfiles.php?group_id=174140>).
From the repository
gscan2pdf uses Git for its Revision Control System. You can browse the
tree at http://gscan2pdf.git.sourceforge.net/git/gitweb.cgi?p=gscan2pdf
Git users can clone the complete tree with "git clone
git://gscan2pdf.git.sourceforge.net/gitroot/gscan2pdf/gscan2pdf"
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.
libforks-perl
a drop-in replacement for Perl threads using fork()
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/>
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
(<https://sourceforge.net/tracker/?group_id=174140&atid=868098>).
Please include the output of "gscan2pdf --debug" with any new bug
report.
Translationsgscan2pdf 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.
Import
Imports 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 dpi)
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.
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.
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 or ocropus 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 400dpi is necessary for decent
results.
Up to v2.03, the only way to tell which languages were available to
tesseract was to look for the language files. Therefore, gscan2pdf
checks the following paths:
$ENV{TESSDATA_PREFIX}/tessdata
/usr/local/share/tessdata
/usr/share/tesseract-ocr/tessdata
/usr/share/tesseract/tessdata
/usr/share/tessdata
If there are no language files in the above locations, then it
gscan2pdf assumes that tesseract v1.0 is installed, which had no
language files.
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">
To Do
· Print (using Net::Cups).
· Copier.
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
· BjA~Xrn Lindqvist for the gtkimageview widget
· Sourceforge for hosting the project.
perl v5.10.1 2010-02-01 GSCAN2PDF(1)
