Northwestern University

The library at Northwestern University

The library at Northwestern University

Repository | images

Northwestern University is working on a Hydra application that provides extensive functionality for its image collections.

What is Repository | images?

Repository | images is an Hydra application that provides a repository solution for discovery of and access to images for the public, faculty, students, and scholars.


In 2007 the Library assumed responsibility for the Visual Media Collection (Art History Slide Library) and had to evaluate issues in three major areas of image collection management: digitization and cataloging, service assessment, and providing tools to make the collection useable. The Visual Media Collection was to become a wider Digital Image Library, thus collections and affiliated services were evaluated to determine how they would integrate with the digital repository and transition from serving one discipline to many. The result was the development of Repository | images : an institutional repository for images built using the Hydra technology framework and based on the Fedora digital repository system.  The application went into production for the 2013 fall semester.

Some important features are:

Users with a NetID can …

  • Access the collection of 115,000 images
  • Build a custom collection of images using drag-and-drop
  • Re-order images within a custom collection using drag-and-drop
  • Nest custom collections within other collections
  • PowerPoint size / Small (JPG) image download
  • Create details/crops of images
    • add those details/crops to custom collections
  • Upload personal images
    • Add item level metadata
  • Export a custom collection to a PowerPoint presentation
  • Share to logged in users
  • Zoom, rotate images

Users without a NetID can ..

  • Access digital library collections that are defined as public
  • Publication size / Large (TIFF) image download for certain collections (World War II posters)
  • PowerPoint size / Small (JPG) image download
  • Zoom, rotate images

Our Hydra application also has a REST API that a robust metadata cataloging tool and a migration process utilize. This Hydra-based API ensures that the objects get indexed in Solr and updated in Fedora, all with simple REST calls.


Northwestern University is collaborating with Indiana University on the Avalon Project.  Avalon uses Hydra technologies to provide a powerful repository for use with video materials.

University website:

Images Repository website:

Avalon website: