GSCAN2PDF(1)          User Contributed Perl Documentation         GSCAN2PDF(1)

       gscan2pdf - A GUI to produce PDFs or DjVus from scanned documents

       1. Scan one or several pages in with File/Scan
       2. Create PDF of selected pages with File/Save


       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
       --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'.
       --import=<PDF|DjVu|images> Imports the specified file(s). If the
       document has more than one page, a window is displayed to select the
       required pages.
       --import-all=<PDF|DjVu|images> Imports all pages of the specified
       --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).

       To diagnose a possible error, start gscan2pdf from the command line
       with logging enabled:

       "gscan2pdf --log=file.log"

       and check file.log.


       gscan2pdf creates a text resource file in ~/.config/gscan2pdfrc. The
       directory can be changed by setting the $XDG_CONFIG_HOME variable.
       Generally, however, preferences should be changed via the
       Edit/Preferences menu, or are captured automatically during normal
       usage of the program.

       None known.

       Whilst it is possible to import PDFs, this is intended to be able to
       round-trip files created by gscan2pdf.

       gscan2pdf is available on Sourceforge

       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"

       Download the rpm from Sourceforge, and then install it with "rpm -i

   From source
       The source is hosted in the files section of the gscan2pdf project on
       Sourceforge (<>).

   From the repository
       gscan2pdf uses Git for its Revision Control System. You can browse the
       tree at <>.

       Git users can clone the complete tree with "git clone

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.

       "make test" should run several hundred tests to confirm that things
       will work properly on your system.

       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

       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

           libgtk3-perl >= 0.028
               There is a bug in version of libgtk3-perl before 0.028 that
               causes gscan2pdf to crash when saving. Whilst I could prevent
               gscan2pdf from crashing, it would still be impossible to save
               anything, rendering gscan2pdf rather useless.

               A simple interface to Gtk3's complex MVC list widget

           liblocale-gettext-perl (>= 1.05)
               Using libc functions for internationalisation in Perl

               provides the functions for creating PDF documents in Perl

               API library for scanners

               Perl bindings for libsane.

               manages sets of integers

               TIFF manipulation and conversion tools

               Image manipulation programs

               A perl interface to the libMagick graphics routines

               API library for scanners -- utilities.

               scanner graphical frontends. Only required for the scanadf

               post-processing tool for scanned pages. See

               Desktop integration utilities from Required
               for Email as PDF.  See

               Utilities for the DjVu image format. See

               A command line OCR. See <>.

               A command line OCR. See

               A command line OCR. See <>

               A command line OCR. See <>

       There are two mailing lists for gscan2pdf:

           A low-traffic list for announcements, mostly of new releases. You
           can subscribe at

           General support, questions, etc.. You can subscribe at

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.  The Debian tool "reportbug" provides a convenient
       GUI for doing so.


       Alternatively, there is a bug tracker for the gscan2pdf project on

       Please include the log file created by "gscan2pdf --log=log" with any
       new bug report.

       gscan2pdf has already been partly translated into several languages.
       If you would like to contribute to an existing or new translation,
       please check out Rosetta:

       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
       ( and have a look at the po/
       directory in the source code <>.

       Alternatively, Ubuntu has its own translation project. For the 9.04
       release, the translations are available at


       Clears the page list.


       Opens any format that imagemagick supports. PDFs will have their
       embedded images extracted and imported one per page.

       Note that files can also be imported by dragging them into the
       thumbnail list from a program like nautilus or konqueror.


       Sets options before scanning via SANE.


       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

           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

           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)
           Guarantees that a "no documents" condition will be returned after
           the last scanned page, to prevent endless flatbed scans after a
           batch scan.

           After sending the scan command, wait until the button on the
           scanner is pressed before actually starting the scan process.

           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.


       Saves the selected or all pages as a PDF, DjVu, TIFF, PNG, JPEG, PNM or


       Metadata are information that are not visible when viewing the
       PDF/DjVu, but are embedded in the file and so searchable and can be
       examined, typically with the "Properties" option of the document

       The metadata are completely optional, but can also be used to generate
       the filename see preferences for details.

       The date can be selected with use of the calendar widget. The displayed
       date can be incremented or decremented with use of the '+' and '-'


       Both black and white, and colour images produce better compression than
       PDF. See <> 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.


       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.


       Deletes the selected page.


       Renumbers the pages from 1..n.

       Note that the page order can also be changed by drag and drop in the
       thumbnail view.


       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.


       When an image is scanned, gscan2pdf attempts to extract the resolution
       from the scan options. This nearly always works without problem.

       Importing an image can be trickier, however. Some image formats such as
       PNM do not encode metadata for resolution. In other cases, the data is
       incorrect.  Edit/Properties allows the user to manually correct the
       metadata for a particular page, thus correcting the size of final PDF
       or DjVu. The image itself is otherwise not changed - it is not down- or


       The preferences menu item allows the control of the default behaviour
       of various functions. Most of these are self-explanatory.


       gscan2pdf initially supported 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. These are called

       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.

       In 1.8.3, New Perl bindings for SANE were introduced. These are called
       libimage-sane-perl and are the preferred frontend.

       In 1.8.5, support for libsane-perl was removed.

       Device blacklist

       Ignore listed devices.

       Note that this is a device name regular expression, e.g. /dev/video,
       and not the name as listed in the scan window, e.g. Noname

       Default filename for PDF or DjVu files

       All strftime codes (e.g. %Y for the current year) are available as
       variables, with the following additions:

        %Da    author
        %De    filename extension
        %Dt    title

       All document date codes use strftime codes with a leading D, e.g.:

        %DY    document year
        %Dm    document month
        %Dd    document day

       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


       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.



       unpaper (see <>) 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
       An important conclusion was that 400ppi is necessary for decent

       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.

   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?
       In Edit/Preferences, tick the box "Allow batch scanning from flatbed".

       Some Brother scanners report "out of documents", despite scanning from
       flatbed.  This can be worked around by ticking the box "Force new scan
       job between pages".

       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.

       If you are quick, you might be able to change the document on the
       flatbed whilst the scan head is returning.

       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, and
       therefore only the changelogs from official Ubuntu builds are

   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
       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 (<>)

       ·   plone (<>)

       ·   pdfgrep (<>

       ·   swish-e (<>)

       ·   recoll (<>)

       ·   terrier (<>)

   How can I change the colour of the selection box in the image viewer?
       Create a file called "~/.config/gtk-3.0/gtk.css" with the following

        flowbox rubberband,
        treeview.view rubberband,
        .content-view rubberband,
        .content-view .rubberband {
          border: 1px solid #2a76c6;
          background-color: rgba(42, 118, 198, 0.2); }

   How can I change the colour of the OCR output
       Create a file called "~/.config/gtk-3.0/gtk.css" with the following

       #gscan2pdf-ocr-output {
         color: black; }

See Also
       XSane (<>)

       Scan Tailor (<>)

       Jeffrey Ratcliffe (jffry at posteo dot net)

Thanks to
       ·   all the people who have sent patches, translations, bugs and

       ·   the gtk+ project for a most excellent graphics toolkit.

       ·   the Gtk3-Perl project for their superb Perl bindings for GTK3.

       ·   The SANE project for scanner access

       ·   Björn Lindqvist for the gtkimageview widget

       ·   Sourceforge for hosting the project.

       Copyright (C) 2006--2019 Jeffrey Ratcliffe <>

       This program is free software: you can redistribute it and/or modify it
       under the terms of the version 3 GNU General Public License as
       published by the Free Software Foundation.

       This program is distributed in the hope that it will be useful, but
       WITHOUT ANY WARRANTY; without even the implied warranty of
       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 <>.

perl v5.30.1                      2019-12-14                      GSCAN2PDF(1)