IIIF: International interfaces for image-based cultural assets

IIIF (pronounced Triple -I-F) is an acronym for the International Image Interoperability Framework - a technical standard dedicated to providing unified access to image-based cultural assets from around the world. IIIF was invented in the scope of cultural heritage digitization and is maintained and will be developed further by a growing community of cultural institutions. As part of the Polonsky Foundation digitization project "Manuscripts from German-Speaking Lands", the introduction of the IIIF technology is being tested at the HAB. The project is three-year cooperation between the Bodleian Libraries and the Herzog August Bibliothek. Together the two libraries will digitize approximately 600 manuscripts.

The IIIF consortium is approaching the challenges of digitization by defining programming interfaces (see info box) and thereby creating an excellent user experience for displaying, comparing, editing and annotating images. A special focus lies on the interoperability of the digitized material; traditionally, each library has its own image repository (colloquial and pejorative: data silo), which can be accessed with a wide variety of viewers. The programming interfaces defined by IIIF are to be understood as universal tools that allow access to digital copies from several repositories at the same time. 

In addition to the manuscript department, employees of the digital library, the photography department and the IT department were involved in the implementation of IIIF at the HAB. Of course, such an innovation also entails infrastructural changes and requires the adaptation of workflows.

The results of the introduction of this unifying technology at the HAB can be seen in the digitized manuscripts from the Polonsky Foundation digitization project, which are available at https://hab.bodleian.ox.ac.uk/en/digitised-items/.


The introduction of IIIF facilitated processes which would have meant extensive organizational efforts before: The presentation of digitized manuscripts from both institutions in a common format with uniform accompanying information. As a result, the close collaboration between the Bodleian Libraries and the Herzog August Bibliothek is clearly noticeable for the viewers of the digitized manuscripts from both institutions.




The technical details...

IIIF defines the following four application programming interfaces (API):

The Image API... provides images of digitized cultural objects. Information about the region, size, rotation, quality characteristics and format of the requested image is transmitted via the URL.

The Presentation API... provides metadata (in JSON-LD format) describing the structure and content of the digitized objects. This metadata indicates, amongst other information, what kind of object it is and in what order the digitized pages have to be displayed.

The Authentication API... is used to regulate access to certain objects as required and to implement access controls if necessary.

The Content Search API... allows users to search for full text and annotations within an object.

For more information on IIIF see http://iiif.io