SiriusGeoAnnotator: Ontology-driven Knowledge Graph Population for Geological Image Annotation

Retrieving geological images according to the geological information they embed is a complex task that requires to extract this information and represent it in a way that can be accessible to geoscientists. We have designed and implemented SiriusGeoAnnotator—a system that generates annotations in the form of a knowledge graph and drives the annotation process according to an ontology and the previously generated annotations. We have also implemented SiriusGeoOnto—an ontology tailored to the semantic annotation of geological images. The creation of a knowledge graph to represent the annotations enables the use of the available Semantic Web infrastructure to perform automated reasoning and explore the annotations via semantic queries.

SiriusGeoAnnotator applies the notion of navigation graph to present the user with relevant annotation suggestions. The suggestions are exhaustive but presented on-demand to avoid overloading the user interface. SiriusGeoAnnotator also includes autocompletion features to facilitate the search of the relevant annotations. The navigation graph relies on the support of the OWL 2 reasoner HermiT reasoner to obtain the classification of the ontology and the triplestore reasoner RDFox to saturate the knowledge graph (i.e., entail new triples) according to the axioms in the ontology.

Documentation and Demo

A public demo is available here:

Documentation: a quick start guide, extended guidelines, poster and demo videos.

Source Codes

The source codes of SiriusGeoAnnotator are available on Gitlab under the GNU General Public License version 2 as published by the Free Software Foundation.

The back-end relies on RDFox for which an academic license can be requested.

SiriusGeoAnnotator uses Java 8 features and Maven for project organisation and build. SiriusGeoAnnotator has been tested on Windows, Linux and macOS. The source code also contains a Dockerfile that can be used to provide a Tomcat server ready to run SiriusGeoAnnotator (tested on Tomcat 9).

The SiriusGeoOnto Ontology

We have designed and implemented the SiriusGeoOnto ontology to cover the information embedded in the geological images. SiriusGeoOnto has been modelled in the OWL 2 ontology language using the ontology editor Protégé. SiriusGeoOnto includes the hierarchy of geological periods of time based on the International Chronostratigraphic Chart (v2018/08).

SiriusGeoOnto is publicly available as a Zenodo dataset:

Knowledge Graph Exploration

The generated knowledge graph can be accessed, in a standard way, as a RDF graph via SPARQL queries. To do so we have set up a SPARQL endpoint that can be accessed programmatically (e.g., via Python or Java) or via user-friendly systems like SemFacet and OptiqueVQS that deal with the query generation.

Relevant Publications


This work was supported by the SIRIUS Centre for Scalable Data Access (Research Council of Norway, project 237889).