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 PageXML 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 and the web application. A short user manual is available here.

Mainly due to the efforts of @NesbiDevelopment over the last few months all existing functionality has been successfully integrated into the web tool and several additional enhancements and bug fixes have been made.

As a next step we plan to restructure parts of the client server communication since the current solution lacks modularity which already caused some issues in the past. Performing these modifications will probably take 1-2 months. However, with these changes made, the realization of the next two planned milestones (segmenting by component selection and vastly improved editing/post correction options) should become a lot easier.

Obviously, we will still try to deal with upcoming or already existing issues. However, depending on their cost-benefit ratio some issues might be put on hold for the time being.

In the last few weeks a new, browser based GUI has been built from scratch. This also required some substantial changes within the rest of the code. We are now working on a step by step adaption and integration of the existing functionality. Nevertheless, feel free to start testing right away but please keep in mind that it's work in progress.

For this guide tomcat version 7 is used.

apt-get install tomcat7

apt-get install maven

apt-get install openjdk-8-jdk

git clone https://github.com/chreul/LAREX.git

run mvn clean install -f LAREX/Larex/pom.xml.

Either: sudo ln -s $PWD/LAREX/Larex/target/Larex.war /var/lib/tomcat7/webapps/Larex.war

or cp LAREX/Larex/target/Larex.war /var/lib/tomcat7/webapps/Larex.war

systemctl start tomcat7

to restart systemctl restart tomcat7

to start automatically at system boot systemctl enable tomcat7

It is recommended to use Eclipse.

In Eclipse go to Help -> Install New Software -> Work with neon -> Install Web, XML, Java EE and OSGi Enterprise Development

Install Maven as seen above and build the project.

Download the most recent version under http://tomcat.apache.org/download-90.cgi.

Select the web perspective and add the Tomcat server.

Install homebrew (see https://brew.sh/).

Afterwards install all required packages (java, Tomcat, git, and maven): brew cask install java brew install tomcat git maven

To verify the Tomcat installation use homebrew’s services utility. Tomcat should now be listed here: brew services list

Run in your desired project directory git clone https://github.com/chreul/LAREX.git to clone the repository.

run mvn clean install -f LAREX/Larex/pom.xml.

Either: sudo ln -s $PWD/LAREX/Larex/target/Larex.war /usr/local/Cellar/tomcat/[version]/libexec/webapps/Larex.war

or cp LAREX/Larex/target/Larex.war /usr/local/Cellar/tomcat/[version]/libexec/webapps/Larex.war

brew services start tomcat

to restart 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 Configuration for more information).

Larex contains a configuration file (src/webapp/WEB-INF/larex.config) 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.

<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

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 aswell 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>
	<input type="submit"/>
</form>

Reul, Christian; Springmann, Uwe; Puppe, Frank: LAREX – A semi-automatic open-source Tool for Layout Analysis and Region Extraction on Early Printed Books. In Proceedings of the 2nd International Conference on Digital Access to Textual Cultural Heritage (2017). ACM. Draft available at arXiv.

Reul, Christian; Dittrich, Marco; Gruner, Martin: Case Study of a highly automated Layout Analysis and OCR of an incunabulum: ‘Der Heiligen Leben’ (1488). In Proceedings of the 2nd International Conference on Digital Access to Textual Cultural Heritage (2017). ACM. Draft available at arXiv.