Validate and transform between OCR file formats (hOCR, ALTO, PAGE, FineReader)
You can run the command line scripts and web interface as a Docker container, you only need Docker installed.
To start the web interface on http://localhost:8080:
docker run --rm -it -p 8080:8080 ubma/ocr-fileformat
To run the command line scripts, mount the directory containing your input
files into the container's /data
directory:
docker run --rm -it -v "$PWD":/data ubma/ocr-fileformat ocr-transform alto2.0 hocr somefile.alto
To install system-wide to /usr/local
:
sudo make install
To install without sudo
to your home directory:
make install PREFIX=$HOME/.local
If $HOME/.local/bin
is not in your PATH
, add this to your shell startup file (e.g. ~/.bashrc
or ~/.zshrc
):
export PATH="$HOME/.local/bin $PATH"
The web application has a PHP backed. You can deploy it on any PHP-capable
server by copying the web
folder somewhere below the document root
of your server, e.g. /var/www/html
for Apache on Debian/Ubuntu:
sudo -u www-data cp -r web /var/www/html/ocr-fileformat
In this example the GUI would be available under http://localhost/ocr-fileformat/.
The project offers two functionalities, which can be accessd via a command line script (CLI), using a web interface (GUI) or in you own tools (API)
ocr-transform
: Transformation of OCR output between OCR formatsocr-validate
: Validation of OCR output against OCR format schemasThe web interface is for testing validation and transformations. You can upload a file or select an input file by URL.
$PREFIX/share/ocr-fileformat/xslt
- XSLT stylesheets$PREFIX/share/ocr-fileformat/xsd
- XSD schemas$PREFIX/share/ocr-fileformat/script/transform
- Transformation scripts$PREFIX/share/ocr-fileformat/script/validate
- Validation scriptsUsage: ocr-transform [-dl] <input-fmt> <output-fmt> [<input> [<output>]] [-- <saxon_opts>]
For example, you can transform an ALTO XML to a hOCR file with:
ocr-transform alto hocr sample.xml sample.hocr
Or convert from ALTO XML (version 2.1) to hOCR with:
ocr-transform alto2.1 hocr sample.alto sample.hocr
You can also pass arguments directly to the Saxon CLI by passing them after a double dash (--
). For example, to set the foo
parameter to bar
:
ocr-transform alto hocr sample.xml sample.hocr -- foo=bar
Try ocr-transform -h
to get an overview:
Usage:
ocr-transform [OPTIONS] <from> <to> [<infile> [<outfile>]] [-- <script-args>]
ocr-transform [OPTIONS] <from> <to> --help-args Show script-args, and exit
ocr-transform [OPTIONS] -h|--help Show this help, and exit
ocr-transform [OPTIONS] -v|--version Show version, and exit
ocr-transform [OPTIONS] -L|--list List available from/to, and exit
Options:
--debug -d Increase debug level by 1, can be repeated
Transformations:
abbyy hocr
abbyy page
alto hocr
alto page
alto text
alto2.0 alto3.0
alto2.0 alto3.1
alto2.0 hocr
alto2.1 alto3.0
alto2.1 alto3.1
alto2.1 hocr
alto4.2 alto2.1
gcv alto
gcv hocr
gcv page
hocr alto
hocr alto2.0
hocr alto2.1
hocr alto3.0
hocr alto4.0
hocr page
hocr tei
hocr text
mybib alto3.0
page alto
page alto_legacy
page hocr
page page2019
page text
tei hocr
textract page
Select the Transform
menu option. Choose a URL, an input and an output
format. Click Transform
.
The stylesheets are installed in $PREFIX/share/ocr-fileformat/xslt
and can be
used directly in your scripts and software. You will need to use an XSLT 2.0
capable stylesheet transformer.
From ╲ To | hOCR | ALTO | PAGEXML | TEI | Text |
---|---|---|---|---|---|
hOCR | - | ✓ | ✓ | ✓ | ✓ |
ALTO | ✓ | ✓ | ✓ | - | ✓ |
PAGEXML | ✓ | ✓ | ✓ | - | ✓ |
ABBYY FineReader | ✓ | - | ✓ | - | - |
Google Cloud Vision | ✓ | ✓ | ✓ | - | - |
Amazon AWS Textract | - | - | ✓ | - | - |
TEI | ✓ | - | - | - | - |
Usage:
ocr-validate [OPTIONS] <schema> <file> [<resultsFile>]
ocr-validate [OPTIONS] -h|--help Show this help, and exit
ocr-validate [OPTIONS] -v|--version Show version, and exit
ocr-validate [OPTIONS] -L|--list List available schemas, and exit
Options:
--debug -d Increase debug level by 1, can be repeated
Schemas:
hocr
alto-1-0 alto-1-1 alto-1-2 alto-1-3 alto-1-4 alto-2-0 alto-2-1 alto-2-2-draft alto-3-0 alto-3-1 alto-3-2-draft alto-4-0 alto-4-1 alto-4-2 alto-4-3
abbyy-6-schema-v1 abbyy-8-schema-v2 abbyy-9-schema-v1 abbyy-10-schema-v1
page-2009-03-16 page-2010-01-12 page-2010-03-19 page-2013-07-15 page-2016-07-15 page-2017-07-15 page-2018-07-15 page-2019-07-15
For example, to validate an XML file against the ALTO 3.1 schema:
ocr-validate alto-3-1 myFile.alto
Select the Validate
menu option. Choose a URL and an schema. Click Validate
.
The XSD files are installed under $PREFIX/share/ocr-fileformat/xsd
hOCR | ALTO | PAGEXML | FineReader | Google Cloud Vision | Amazon AWS Textract | |
---|---|---|---|---|---|---|
Validation | ✓ | ✓ | ✓ | ✓ | - | - |
This is free software. You may use it under the terms of the MIT License.
During the installation process several projects are included (in ./vendor
). These projects have different licenses:
MPL
.CC BY SA 4.0
since ALTO 4.0?
Apache 2.0
?
MIT
MIT
CC BY 4.0
Apache 2.0
Apache 2.0
Apache 2.0
Apache 2.0