The ZERI & LODe project stems from a joint venture between the Federico Zeri Foundation and a team of ICT and digital humanities experts from Bologna University, the aim being to transform the Zeri Photo Archive catalogue data into Linked Open Data, thus making them accessible, retrievable and re-usable by users and other applications, in line with the new semantic web and its requirements.

The need to display data in the form of Linked Open Data forms part of the PHAROS (Photo Archives Online Search) project, of which the Foundation is a member. That Consortium links 14 art historical photo archives of international calibre in Europe and the USA. Their pooled resources amount to 25 million images. The Consortium fosters active collaboration among the partner institutions towards creation of a common platform for research into images and metadata pertaining to works of art.

LOD were chosen as the medium for data sharing. To ensure they have the widest possible semantic interoperability, the data have been mapped mainly on the international standard CIDOC-CRM.


One important phase of the ZERI & LODe project has been research into the field of ontological development. Before being made open, the data are structured according to an ontological model which:

  • reflects the analytical principles of the OA and F ministerial files used to describe the Zeri Photo Archive photographs
  • captures the complexity of the photo object
  • translates the specific qualities of an artwork photo into an archive system
  • enhances and upgrades the semantic resources of the Zeri Photo Archive catalogue

supplies the shortcomings of CIDOC-CRM by integrating with other established ontologies.

This process has led to publication of the available OA Entry and F Entry ontologies on the ZERI & LODe website, along with the rest of the documentation.

The RDF dataset and integration of the Zeri Photo Archive catalogue

At present the RDF dataset comprises the subset of data pertaining to 16th-century Italian painting which are already available on the Zeri Foundation website and partially retrievable on the Europeana portal.

Some 19,000 artworks and 31,000 photographs, as well as information on artists, photographers, bibliography and relevant documentation, are described by over 11 million triple RDFs.

To assist with preliminary exploration of RDF-format data, a special interface has been set up in Lodview. Data can be downloaded from the dedicated website page and re-used under CC-BY license.

The Zeri Photo Archive online catalogue has been enriched by LOD integrating it by links to authorities and datasets available in Linked Open Data: links to the Getty ULANViafDBpedia, and Wikidata records and Wikipedia pages are available concerning artists and photographers; links to Getty Art and Architecture Thesaurus (AAT) records are scheduled for terms pertaining to art objects and photographs; while links to Geonames records will be provided to supply names of geographical locations.