LAREX is a semi-automatic open-source tool for layout analysis on early printed books. It uses a rule based connected components approach which is very fast, easily comprehensible for the user and allows an intuitive manual correction if necessary. The PAGE XML format is used to support integration into existing OCR workflows. Evaluations showed that LAREX provides an efficient and flexible way to segment pages of early printed books.
Please feel free to visit the tool homepage. A short user manual is available here.
Additional information about developing for LAREX see here
This guide uses Docker and allows a platform agnostic installation of LAREX
- See: LAREX Docker
- Configure
development/build.sh, runcd developmentandsh build.sh
This guide uses Tomcat 8, Java 8 and Ubuntu (please adjust accordingly for your setup)
- Install required packages:
apt-get install tomcat8 maven openjdk-8-jdk - Clone Repository:
git clone https://github.com/OCR4all/LAREX.git - Compile:
mvn clean install -f LAREX/pom.xml. - Copy or link the created war file to Tomcat:
- Copy
cp LAREX/target/Larex.war /var/lib/tomcat8/webapps/Larex.war - Link:
sudo ln -s $PWD/LAREX/target/Larex.war /var/lib/tomcat8/webapps/Larex.war
- Copy
- Start Tomcat:
systemctl start tomcat8- (Restart Tomcat via
systemctl restart tomcat8) - (To start Tomcat automatically at system boot
systemctl enable tomcat8)
- (Restart Tomcat via
This guide uses Eclipse to simplify the setup on Windows
- Install Eclipse IDE for Enterprise Java Developers from the official website
- Download Tomcat 8 or up from the official website
- Create a Tomcat server in eclipse:
- Open
Window->Show View->Other...->Server->Servers - Click prompt to add a new server, select
Apache->Tomcat <version> Server->Next-> set your Tomcat installation directory ->Finish.
- Open
- Clone Repository:
File->Import->Git->Projects from Git->Clone URI-> SetURI: https://github.com/OCR4all/LAREX.git->[✓] master->Next >->Next >->Import as gernal project->Finish
- Set as Maven Project:
- Import Project
- Right click on
Larex->Configure->Convert to Maven Project->Finish
- Right click on
- Update maven project (if not updated automatically)
- Rightclick on
Larex->Maven->Update Project...->OK
- Rightclick on
- Start Larex
- Right click on
Larex->Run As->Run on Server.
- Right click on
Note: LAREX is mainly developed on Linux so the macOS build introductions may be outdated from time to time. If this is the case, feel free to contact us This guide uses homebrew (please adjust accordingly for your setup).
- Install Homebrew (see https://brew.sh/) and run
brew update. - Install required packages:
brew cask install adoptopenjdk8brew install tomcat git maven
- (Verify Tomcat installation):
brew services listtomcat should be listed in the output of this command
- Clone Repository:
git clone https://github.com/OCR4all/LAREX.git
- Compile:
- run
mvn clean install -f LAREX/pom.xml.
- run
- Copy or link the created war file to Tomcat
- Copy:
cp LAREX/target/Larex.war /usr/local/Cellar/tomcat/[version]/libexec/webapps/Larex.war - Link:
ln -s $PWD/LAREX/target/Larex.war /usr/local/Cellar/tomcat/[version]/libexec/webapps/Larex.war
- Copy:
- Start Tomcat:
brew services start tomcat- (Restart Tomcat via
brew services restart tomcat)
Go to localhost:8080/Larex.
You can add your own books by copying them to src/webapp/resources/books
(Or an alternative direction set in the config file. See section Configuration for more information).
Book directories must have the following structure:
bookDir/
├── <book_name>/
│ ├── <page_name>.png
│ └── <page_name>.xml
└── <book2_name>/
└── …
Detailed information about the usage of LAREX can be found in the OCR4all getting started guides.
See sections and chapters about Segmentation, Ground Truth Correction and Post Correction.
LAREX contains a configuration file (src/webapp/WEB-INF/larex.properties) with a few settings that can be set before running the application.
The setting bookpath sets the file path of the books folder.
e.g. bookpath=/home/user/books (Linux)
e.g. bookpath=C:\Users\user\Documents\books (Windows)
LAREX will load the books from this folder.
[default /src/main/webapp/resources/books]
The setting localsave tells the application how to handle results locally when saved.
Please note:
To work properly in local mode it's required that the Page@imageFilename-attribute matches the actual filename (apart from the extension). This label will be used for local storage.
<mode>=[bookpath|savedir|none]
bookpath: save the result in the bookpath
savedir: save the result in a defined savedir
none: do not save the result locally [default]
e.g. localsave:bookpath
The setting savedir is needed if localsave mode is set to "savedir".
e.g. savedir=/home/user/save (Linux)
e.g. savedir=C:\Users\user\Documents\save (Windows)
The setting websave tells the application how to handle results on the browser side when saved.
<value>=[true|false]
true: download the result after saving [default]
false: no action after saving
e.g. websave=true
Set the accessible modes in the LAREX GUI <value>=[[segment][edit][lines][text]]
A combination of the modes "segment", "edit", "lines" and "text" can be set as
a space separated string.
e.g. modes=segment lines
The order of those modes in the string also determines which mode is opened on startup, with the first in the list being opened as main mode. The mode "segment" can be replaced with "edit" in order to hide all auto segmentation features. ("edit" will be ignored if both are present)
[Default] modes=segment lines text
This setting enables or disables the direct open feature.
<value>=[enable|disable]
This feature allows users to load a book from everywhere on the servers drive as well as to alter the options websave, localsave and savedir.
enable: enable direct request
disable: disable direct request [default]
e.g. directrequest=enable
This feature should be used with caution but is very useful when using LAREX in a workflow with other web applications. (e.g. in Docker)
The easiest direct request would be via a html form with the values bookpath, bookname, websave (optional), localsave (optional) and savedir (optional).
<form action="http://localhost:8080/Larex/direct" method="POST">
bookpath: <input type="text" name="bookpath"/><br>
bookname: <input type="text" name="bookname"/><br>
websave: <input type="text" name="websave"/><br>
localsave: <input type="text" name="localsave"/><br>
savedir: <input type="text" name="savedir"/><br>
modes: <input type="text" name="modes"/><br>
<input type="submit"/>
</form>This setting enables or disables OCR4all UI mode.
<value>=[enable|disable]
This setting allows displaying and/or hiding certain UI elements when LAREX is used in combination with OCR4all.
enable: enable OCR4all UI mode
disable: disable OCR4all UI mode [default]
e.g. ocr4all=enable
If you are using LAREX please cite:
Reul, C., Springmann, U., Puppe, F.: Larex: A semi-automatic open-source tool for layout analysis and region extraction on early printed books Proceedings of the 2nd International Conference on Digital Access to Textual Cultural Heritage (2017)
@inproceedings{reul2017larex,
title={Larex: A semi-automatic open-source tool for layout analysis and region extraction on early printed books},
author={Reul, Christian and Springmann, Uwe and Puppe, Frank},
booktitle={Proceedings of the 2nd International Conference on Digital Access to Textual Cultural Heritage},
pages={137--142},
year={2017}
}
![dependabot[bot] avatar](https://avatars.githubusercontent.com/in/29110?v=4 "dependabot[bot]")
React
Typescript
Django
Laravel
Facebook
Microsoft
Google
Alibaba
D3
Tencent