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Technologies and Software Development

IIIF and Mirador

The Bavarian State Library is proud to make a growing part of its digital collections available via the IIIF standard. IIIF (pronounced 'Triple-I-F') stands for International Image Interoperability Framework and comprises a number of interfaces which are jointly developed by the worldwide GLAM community (GLAM='Galleries, Libraries, Archives, Museums') in an open process.

Open standards and public APIs instead of silos

Since the beginning of cultural property digitization in the 1990s, numerous technical solutions were developed for Internet presentation of digital assets from libraries, archives, and museums. Therefore, today's users of digital image repositories are compelled to deal with a variety of viewers and diverse functionalities. These numerous, isolated technical solutions have become a major challenge for digitizing facilities, especially in terms of maintenance and care. The standards of IIIF allow uniformed data provision, simple data exchange and higher user-friendliness, and thus offer the best conditions for international cooperation in research.

IIIF Technology

The International Interoperability Framework (IIIF) consists of two Application Programming Interfaces (APIs):

  • The Image API defines a web service for the delivery of images. Adjustments are possible in terms of format, output size, zoom level, cropping, color depth or rotation.

  • The Presentation API describes a service for the delivery of structural and presentation information about digital content. The output is done as JSON-LD object [example of a JSON-LD object]; the output of the images according to the Image API is integrated.

IIIF offers unprecedented interoperability, cross-institutional exchange of digital objects and location-independent display in a wide variety of viewers. The standards enable:

  • Maintenance and servicing of only one uniform technical infrastructure

  • Provision of high-resolution images with a dot density of 300 ppi and more

  • Uniform interfaces that can be used internally and externally, and thus interoperability with other IIIF image repositories

  • Re-use of a growing number of IIIF-compliant developments, e.g. viewers like Mirador or Universal Viewer for videos, audio, images and 3D objects

Mirador Viewer

The MDZ uses the viewer software Mirador for its IIIF web presence. The software, a development of the universities Harvard and Stanford within the IIIF community, runs as a browser application based on HTML5 and JavaScript. Besides viewing and browsing digital objects, Mirador allows annotating and comparing objects from various IIIF-compliant repositories worldwide. Further functions are stepless zooming in high-resolution images as well as temporary image manipulation (rotation of the image, change of brightness, contrast and saturation, inversion of colors ('negative view'), greyscale). In addition, Mirador offers URL generation to a specific image section for use in a CMS or for download. A video help for use can be found on our help page.

The IIIF Community

The International Image Interoperability Framework was created in 2011 with the support of the Mellon Foundation from a joint initiative of renowned memory organizations, including Harvard University, Stanford University Libraries, Cornell University, British Library, Bodleian Libraries (Oxford) and the national libraries of France and Norway. Today the IIIF community is supported by numerous museums, libraries and archives scattered around the globe. The Bavarian State Library itself has been a member of the IIIF Core Founding Member Consortium since June 2015.

Open Source

The MDZ relies on open standards for its software. Therefore we do not only use Open Source products, but also participate in their development. In addition, we make reusable components of our own products available under an open source license and develop them in constant dialogue with the community. Examples are our Java implementation of the IIIF standard, plugins to highlight OCR in Solr, Java bindings for high-performance JPEG and JPEG2000 processing and our data processing framework Flusswerk.

You can find an overview of all our Open Source products on GitHub.