Scantpaper

A GUI to produce PDFs or DjVus from scanned documents.

Scantpaper is a Linux application (it needs GTK3, SANE, and a Python 3 interpreter, all of which are available on other Unix-like systems like MacOS or BSD as well). It is the Python rewrite (v3) of the popular gscan2pdf.

Scan single- or double-sided, with automatic interleaving
OCR with tesseract for searchable PDF/A, without the need for temporary files
Edit with crop, rotate, threshold, unsharp mask, and unpaper clean-up
Save as PDF, DjVu, TIFF, PS, TXT, hOCR, or image files
Recover crashed sessions and restore them on the next start

Screenshot: Main page

Quick Start

Install scantpaper and its dependencies (see Download, Installation & Removal), then:

Start the application with scantpaper (or python3 -m scantpaper.app from a source checkout, with PYTHONPATH=src set). Add --debug|info|warn|error|fatal to enable logging at the required level.
Scan one or several pages with File → Scan.
Select the pages and create a PDF with File → Save.
To make the saved PDF searchable, enable OCR in the scan window or run Tools → OCR before saving.

Description

scantpaper provides a GUI for scanning, editing, and saving documents as PDF, DjVu, TIFF, PS, TXT, hOCR, SDB (scantpaper session), or image files (PNG, JPEG, PNM, GIF), and can prepend or append to an existing PDF. It supports batch scanning, metadata, OCR, and various editing tools.

How it works

Scans are acquired with SANE and held in a session database while you edit them. When saving, PDFs are produced with img2pdf and OCR'd with ocrmypdf (which produces PDF/A out of the box); DjVu export uses djvulibre-bin, TIFF export uses libtiff, and images are written with ImageMagick.

┌─────────┐   ┌─────────────────┐   ┌──────────────┐   ┌──────────────────┐
│  SANE   │   │ SQLite session  │   │ edit tools / │   │ img2pdf /        │──▶ PDF (PDF/A)
│ scanner │──▶│ (pages in temp  │──▶│ OCR          │──▶│ ocrmypdf         │
│         │   │  directory)     │   │ (tesseract)  │   ├──────────────────┤──▶ DjVu
└─────────┘   └─────────────────┘   └──────────────┘   │ djvulibre-bin    │
                                                       ├──────────────────┤──▶ TIFF
                                                       │ libtiff          │
                                                       ├──────────────────┤──▶ PNG, JPEG, PNM, GIF
                                                       │ imagemagick      │
                                                       └──────────────────┘

Page Numbering

Page numbers are always consecutive (1, 2, 3, …). Deleting a page renumbers the remainder automatically, and editing a page's number in the document table moves that page to the corresponding position.

Scan Flow

Single-sided: Each scan is appended at the end.
Double-sided: Scan all facing pages first (front 1, front 2, …, front n); they are appended in order. When you flip the stack the ADF feeds them in reverse (back of page n, then back of page n-1, …, back of page 1). Each reverse page is inserted immediately after its matching front page, producing a fully interleaved result: front 1, back 1, front 2, back 2, …, front n, back n.
```
scan pass 1 (fronts):     front 1, front 2, ..., front n
flip stack
scan pass 2 (backs):      back n, back n-1, ..., back 1
interleaved result:       front 1, back 1, front 2, back 2, ..., front n, back n
```
Extended mode (insert before page N): Each new scan is inserted before the selected page, advancing the insertion point for the next scan.

ADF / duplex scanning

Automatic document feeder (ADF) and duplex scans now import every side of the document. Some Brother scanners (e.g. the DS-740D) prefetch the reverse side of a sheet as soon as the front side finishes reading; cancelling the scan session between pages discarded that buffered side, so only the first page of a duplex job was imported. Scantpaper no longer cancels the session between pages when scanning from a feeder, which preserves the prefetched side. The session is still cancelled at the end of the batch, when the requested page count is reached, on error, or when you cancel the scan.

For multi-page flatbed batches the behaviour follows gscan2pdf semantics: the Force new scan job between pages preference (enabled via Edit → Preferences, only available when Allow batch scanning from flatbed is enabled) controls whether the session is cancelled between flatbed pages; the session is always cancelled at the end of the batch.

Main Features

Scan: Options for device, page count, source document, side to scan, and device-dependent options (page size, mode, resolution, batch-scan, etc.). Optionally OCR each page on scan. When applying a scan-options profile, the scanner driver may revert an option (some drivers couple or alias options, e.g. page size and scan area); such an option is then set at most twice and dropped for the rest of that apply, so the scan still proceeds instead of ending in a reload-recursion error.
Save: Save selected/all pages in multiple formats. Supports metadata. The Title, Author, Subject, and Keywords fields offer autocompletion, suggesting values from imported documents and values you have entered before. When saving as PDF, the progress bar tracks each page as it is written and reports the PDF conversion step. Imported images are stored in a compact format (JPEG for scanned pages, the original bytes for imported JPEG/PNG files, lossless PNG for bilevel or transparent pages), and PDF saves embed stored JPEG images directly instead of re-encoding them.
Thumbnails: Page thumbnails are generated with a decimate-then-LANCZOS downscale for a sharp preview in the thumbnail panel without slowing down bulk imports, and bilevel or palette pages (common in scanned/OCR PDFs) are anti-aliased so their previews stay legible.
Email as PDF: Attach pages as PDF to a blank email (requires xdg-email).
Print: Print selected/all pages.

Edit Menu

Undo, Redo: Undo or redo the last action.
Cut, Copy, Paste: Cut, copy, or paste selected pages.
Delete: Remove selected pages.
Select: Select all, odd, even, inverted, blank, dark, or modified pages, or pages without (up-to-date) OCR.
Properties: Edit image metadata.
Preferences: Configure default behaviors and frontends.

View Menu

Pan, Select, Select & Pan tools:
- Pan: Use the left mouse button to drag the image or canvas to pan the view
- Select: Use the left mouse button to select a rectangular box
- Select & Pan: Use the left mouse button to select a rectangular box, and the middle mouse button to drag the image or canvas to pan the view
- In all of the above, the mouse wheel zooms in or out.
Zoom: 100%, fit to window, in, and out.
Rendering: pages are shown at high quality whenever they are static, so the full-page view is easy to assess; a faster rendering is used only while you are panning or zooming, for smooth interaction.
Rotate: 90° clockwise, 180°, and 90° anticlockwise.

Keyboard Shortcuts

Action	Shortcut
New	Ctrl+N
Open	Ctrl+O
Scan	Ctrl+G
Save	Ctrl+S
Email as PDF	Ctrl+E
Print	Ctrl+P
Quit	Ctrl+Q
Undo	Ctrl+Z
Redo	Ctrl+Shift+Z
Cut	Ctrl+X
Copy	Ctrl+C
Paste	Ctrl+V
Delete	Del
Select
All	Ctrl+A
Odd	Ctrl+1
Even	Ctrl+2
Invert	Ctrl+I
Blank	Ctrl+B
Dark	Ctrl+D
Modified	Ctrl+M
View
Zoom in	+
Zoom out	−
Rotate 90° clockwise	Ctrl+Shift+R
Rotate 180°	Ctrl+Shift+F
Rotate 90° anticlockwise	Ctrl+Shift+C
Help	Ctrl+H

Tools

Threshold: Binarize images. The value is an ink-strength cutoff: pixels that differ from the paper colour by more than the given percentage are rendered black, so coloured text and annotations (stamps, highlighters) on white paper are kept. The default is 20; values saved by older versions are migrated automatically.
Brightness / Contrast: Adjust brightness and contrast.
Negate: Invert colours.
Unsharp mask: Sharpen images.
Crop: Crop selected pages.
Clean up: Use unpaper to clean up scans.
Split: Split pages vertically or horizontally.
OCR: Use tesseract to create a text layer for the selected pages. The text layer is embedded into saved PDFs, making them searchable, and can be viewed and edited in the text layer window. Page pixels are fed to tesseract in memory and the stored image is reused, so OCR is faster than in previous versions.
User-defined: Run user-defined commands.

User-defined Tool Variables

%i - input filename
%o - output filename
%r - resolution

Command-line Options

scantpaper supports the following options:

--device <device> [...] Specifies the device(s) to use, instead of getting the list from the SANE API. Useful for remote scanners. May be repeated, or given multiple space-separated devices.
--help
Displays help and exits.
--log=<log-file>
Specifies a file to store logging messages. On exit, the log is compressed to <log-file>.xz.
--debug, --info, --warn, --error, --fatal
Defines the log level. Defaults to --debug if a log file is specified, otherwise --warn.
--import=<PDF|DjVu|images>
Imports the specified file(s). For multi-page documents, a window is displayed to select required pages.
--import-all=<PDF|DjVu|images>
Imports all pages of the specified file(s).
--locale=<directory> Sets the directory containing translated messages. See Translations.
--version
Displays the program version and exits.

Example output

$ scantpaper --version
scantpaper X.Y.Z

(Replace X.Y.Z with your installed version.)

$ scantpaper --help
usage: scantpaper [-h] [--device DEVICE [DEVICE ...]]
                  [--import IMPORT_FILES [IMPORT_FILES ...]]
                  [--import-all IMPORT_ALL [IMPORT_ALL ...]] [--locale LOCALE]
                  [--log LOG] [--version] [--debug] [--info] [--warn]
                  [--error] [--fatal]

A GUI to produce PDFs or DjVus from scanned documents

options:
  -h, --help            show this help message and exit
  --device DEVICE [DEVICE ...]
  --import IMPORT_FILES [IMPORT_FILES ...]
  --import-all IMPORT_ALL [IMPORT_ALL ...]
  --locale LOCALE
  --log LOG
  --version             show program's version number and exit
  --debug
  --info
  --warn
  --error
  --fatal

Please see /usr/share/doc/C/scantpaper/documentation.html for more detail

Examples

# Import every page of a PDF, letting you edit before saving
scantpaper --import-all ~/scans/document.pdf

# Import a PDF, choosing the pages to import in a dialog
scantpaper --import ~/scans/document.pdf

# Use a remote scanner
scantpaper --device "net:scanner.example.com:6566"

Scanning is handled with SANE. PDF conversion uses img2pdf and ocrmypdf. TIFF export uses libtiff.

Saved PDFs are marked as created by scantpaper: the document info Creator field and the XMP creator tool begin with scantpaper v<version>, followed by the OCR toolchain used, e.g. scantpaper v3.0.16 / OCRmyPDF 16.13.0 / Tesseract OCR-hOCR 5.5.0. The Producer field continues to name the library that wrote the file.

Diagnostics

To diagnose errors, start scantpaper from the command line with logging enabled:

PYTHONPATH=src python3 -m scantpaper.app --debug

Configuration

scantpaper creates a config file at ~/.config/scantpaperrc. The directory can be changed by setting $XDG_CONFIG_HOME. Preferences are usually set via Edit → Preferences.

If the config file cannot be read as JSON (for example after a partial write or a hand edit), scantpaper rescues as many recognised settings as it can and resets the rest to their defaults. The unreadable original is kept as a backup at ~/.config/scantpaperrc.old, and the start-up message tells you which settings were kept. Wrongly typed values (e.g. a string where a number is expected) are corrected when possible; each correction is written to the log rather than shown in the start-up message. Only values that cannot be corrected are reported. The original file is never silently overwritten: saving on exit waits until the message has been acknowledged.

Scan options saved in the configuration file by gscan2pdf 2.x (whose default-scan-options block has no frontend list) are recognised and applied to the scan dialog on startup, and are kept when the file is written back.

Sessions

All session data (pages, edits, OCR, annotations) is stored in an SQLite database in a temporary directory named scantpaper-????????, created under $TMPDIR (or /tmp) by default. You can change this location in Edit → Preferences. On exit the session directory is cleaned up.

If scantpaper crashes, the session directory survives. On the next start you are asked whether to restore it via File → Open crashed session.

Dependencies

Package names below are the Debian package names. Equivalent packages for other distributions are given in the wheel file installation instructions.

Required

gir1.2-gdkpixbuf-2.0
gir1.2-gtk-3.0
imagemagick
img2pdf
libtiff-tools
ocrmypdf
poppler-utils
python3-gi
python3-gi-cairo
python3-iso639
python3-pil
python3-sane
python3-tesserocr

Optional

djvulibre-bin
qpdf (for PDF encryption)
unpaper
xdg-utils

Development

python3-pytest-mock
python3-pytest-cov
python3-pytest-timeout
python3-pytest-xvfb

Download, Installation & Removal

Requirements

Python 3.10 or later.
The dependencies listed below. They are installed automatically when installing from a wheel or with uv, but must be installed manually when running from a tarball or the repository.

Packaged installs

Debian-based

Debian sid should automatically have the latest version.
```
sudo apt update
sudo apt install scantpaper
```

Ubuntu users can use the PPA:

sudo apt-add-repository ppa:jeffreyratcliffe/ppa
sudo apt update
sudo apt install scantpaper

In either case to remove scantpaper afterwards:

sudo apt remove scantpaper

From a wheel file

Download .whl from Github.

# Install the C-libraries that pip cannot handle:
# For Debian/Ubuntu
sudo apt update
sudo apt install libgirepository-2.0-dev libcairo2-dev pkg-config python3-dev gir1.2-glib-2.0
# For Fedora
sudo dnf install gobject-introspection-devel cairo-devel pkgconf-pkg-config python3-devel
# For Arch
sudo pacman -S gobject-introspection cairo pkgconf python
# For Homebrew
brew install pygobject3 gobject-introspection cairo pkg-config
# Possibly upgrade pip
python3 -m pip install --upgrade pip
# Install from the wheel file, automatically including python dependencies
pip install scantpaper-x.x.x-py3-none-any.whl

If you haven't already, you will then probably have to add ~/.local/bin to your path in order to find the new executable, after which you can start it with:

scantpaper

To then remove it:

pip uninstall scantpaper

With `uv`

To install the runtime dependencies with uv:

uv sync

or with the additional development dependencies:

uv sync --extra test

After which you can start it with:

uv scantpaper

From source

From a tarball

Download .tar.gz from Github. After installing the dependencies listed above:

tar xvfz scantpaper-x.x.x.tar.gz
cd scantpaper-x.x.x
PYTHONPATH=src python3 -m scantpaper.app

From the repository

Browse the code at Github. After installing the dependencies listed above:

git clone https://github.com/carygravel/scantpaper.git
cd scantpaper
PYTHONPATH=src python3 -m scantpaper.app

In either of the above two cases, just delete the source directory to remove it.

Support

Mailing lists:
- gscan2pdf-announce (announcements)
- gscan2pdf-help (general support)

Reporting Bugs

Please read the FAQs first.
Report bugs preferably against the Debian package or Debian Bugs.
Alternatively, use the Github issue tracker.
Include the log file created by scantpaper --log=log with your report. On exit the log is compressed to log.xz, so submit that file.

Translations

scantpaper is partly translated into several languages. Contribute via Launchpad Rosetta.

Scanner option translations come from sane-backends. Contribute via the sane-devel mailing list or SANE project.

To test updated .po files:

python3 dev/compile_mo.py --src po --out src/scantpaper/locale --domain scantpaper
PYTHONPATH=src python3 -m scantpaper.app --log=log --locale=locale

Set locale variables as needed (e.g., for Russian):

LC_ALL=ru_RU.utf8 LC_MESSAGES=ru_RU.utf8 LC_CTYPE=ru_RU.utf8 LANG=ru_RU.utf8 LANGUAGE=ru_RU.utf8 PYTHONPATH=src python3 -m scantpaper.app --log=log --locale=locale

FAQs

Why isn't option xyz available in the scan window?

It may not be supported by SANE or your scanner. If you see it in scanimage --help but not in scantpaper, send the output to the maintainer.

How do I scan a multipage document with a flatbed scanner?

Enable "Allow batch scanning from flatbed" in Preferences. Some scanners require additional settings.

Why is option xyz ghosted out?

The required package may not be installed (e.g., xdg-email, unpaper, imagemagick).

Why can I not scan from the flatbed of my HP scanner?

Set "# Pages" to "1" and "Batch scan" to "No".

Why is the list of changes not displayed when updating in Ubuntu?

Only changelogs from official Ubuntu builds are shown.

Why can't scantpaper find my scanner?

If the scanner is remote and not found automatically, specify the device:

scantpaper --device <device>

How can I search for text in the OCR layer?

Use pdftotext or djvutxt to extract text. Many viewers support searching the embedded text layer.

How can I change the colour of the selection box or OCR output?

Create or edit ~/.config/gtk-3.0/gtk.css:

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

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

What's in a name?

"scant" (https://en.wiktionary.org/wiki/scant) in this sense means "short (of)", as I am trying to digitalise my paperwork, and I liked the play on "scan".

Known Limitations

PDFs larger than 2 GiB

Saving more than approximately 250 uncompressed scanned pages (at 300 dpi, 8-bit grayscale) produces a PDF exceeding 2 GiB. At that size, three tools in the save pipeline overflow 32-bit file offsets and produce truncated or corrupt output:

Component	Tested version	Overflow point	Symptom
img2pdf (pikepdf engine, linearization)	0.6.2	32-bit xref offsets in linearized output	Truncated PDF; first pages readable, later pages missing
Ghostscript (PDF/A conversion via ocrmypdf)	10.07.1	32-bit file access in gs interpreter	Ghostscript error or corrupt output
pikepdf / qpdf (xref-stream linearization, metadata save)	pikepdf 10.5.0, qpdf 12.4.0	32-bit offsets in xref streams	"unable to find /Root dictionary"; PDF unopenable

Scantpaper now estimates the output size before conversion and refuses to save when it would exceed 2 GiB, showing an error message suggesting fewer pages.

When updating dependencies, re-test by saving ~250 high-resolution uncompressed pages (e.g., 7000×5000 px grayscale TIFFs) and verifying the output PDF opens correctly in a PDF viewer. Note that Ghostscript's 64-bit integer support (needed for >2 GiB files) is build-dependent — see the Ghostscript documentation on word size.

History

I started writing gscan2pdf as a Perl & Gtk2 project in 2006. Version 2 switched to Gtk3, but kept the basic software architecture. This stored the pages as temporary files with hashed names, which had a couple of major disadvantages:

Difficult to support PDF/A directly
It was impossible to create documents with more than a few hundred pages, as it ran out of open file handles.
In the event of a crash, it was tedious to recreate the document from the image files.
AFAIK, Perl's support for Gtk4 never extended beyond that provided by introspection.

Therefore I decided in 2022 to completely rewrite gscan2pdf in Python and renamed it for v3 scantpaper. The rewrite:

Supports PDF/A by using ocrmypdf to write PDFs
Stores all session data in a single Sqlite database
Should be simple to migrate to Gtk4

See also the changelog for detailed release notes.

Author

Jeffrey Ratcliffe (jffry at posteo dot net)

Thanks To

All contributors (patches, translations, bugs, feedback)
The SANE project
The authors of img2pdf and ocrmypdf, without which this would have been much harder.

Contributing

See contributing.

Donate

License

This program is free software: you can redistribute it and/or modify it under the terms of the GNU General Public License v3 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 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details.

Name		Name	Last commit message	Last commit date
.github		.github
dev		dev
openspec		openspec
po		po
src/scantpaper		src/scantpaper
.gitignore		.gitignore
.pre-commit-config.yaml		.pre-commit-config.yaml
CONTRIBUTING.md		CONTRIBUTING.md
README.md		README.md
changelog.md		changelog.md
org.scantpaper.desktop		org.scantpaper.desktop
org.scantpaper.desktop.metainfo.xml		org.scantpaper.desktop.metainfo.xml
pyproject.toml		pyproject.toml
release_procedure.md		release_procedure.md
screenshot.png		screenshot.png
tox.ini		tox.ini

Latest commit

History

Folders and files

Repository files navigation

Scantpaper

Table of Contents

Quick Start

Description

How it works

Page Numbering

Scan Flow

ADF / duplex scanning

Main Features

Edit Menu

View Menu

Keyboard Shortcuts

Tools

User-defined Tool Variables

Command-line Options

Example output

Examples

Diagnostics

Configuration

Sessions

Dependencies

Required

Optional

Development

Download, Installation & Removal

Requirements

Packaged installs

Debian-based

From a wheel file

With uv

From source

From a tarball

From the repository

Support

Reporting Bugs

Translations

FAQs

Why isn't option xyz available in the scan window?

How do I scan a multipage document with a flatbed scanner?

Why is option xyz ghosted out?

Why can I not scan from the flatbed of my HP scanner?

Why is the list of changes not displayed when updating in Ubuntu?

Why can't scantpaper find my scanner?

How can I search for text in the OCR layer?

How can I change the colour of the selection box or OCR output?

What's in a name?

Known Limitations

PDFs larger than 2 GiB

See Also

History

Author

Thanks To

Contributing

Donate

License

About

Resources

Contributing

Stars

Watchers

Forks

Releases

Packages

Used by

Contributors

Languages

With `uv`