OCLC has enhanced its CONTENTdm digital asset management system to expand its support of the International Image Interoperability Framework (IIIF). IIIF, initially proposed in 2011, has gained broad support among digital archive communities for its ability to provide interoperability among collections even when they are based on different image repository platforms. Support of IIIF in CONTENTdm, the most widely implemented digital asset management systems used by libraries, substantially expands the body of materials available within this interoperability framework.
Overview of the International Image Interoperability Framework
IIIF enables researchers to work with multiple image collections using the same interface or tools even when each is based on a different digital asset management system. Virtual aggregate collections can be presented on a given area of interest spanning diverse image repositories. The framework would also enable a unified presentation of collections that have been separated and curated by different institutions. If multiple institutions own and have digitized different fragments for the same manuscripts, a complete presentation of the manuscript could be presented if each repository has implemented IIIF.
The framework includes multiple APIs to enable different aspects of interoperability between image repositories and viewers:
- Image Delivery API (current version 2.1). Implemented on a repository to respond to requests for images through a web service. The Image Delivery API makes a repository able to interoperate with clients or viewers that implement the API for requesting images. This API includes parameters to specify whether the full image or specific regions of the image should be delivered; any rotation values; if the image should be scaled to an alternate resolution; if the image should be delivered in color, grayscale, or bitonal; and its format (JPG, TIFF, PNG, etc.).
- Presentation API (current version 2.1) provides a standard way to describe the structure of digital objects on a repository to enable a viewer or client to present a correct representation of those objects in its interface. The structure of the object is delivered through a manifest, formatted in JSON-LD that describes its images and metadata.
- Search API (current version 1.0) specifies a protocol for performing a search within a given resource for text within its annotations. It is not a general search facility for discovering the resources available with a given repository.
- Authentication API (current version 1.0) enables access to images in a repository that has enabled access restrictions.
The API acts on the basis of existing authentication mechanisms that may be implemented on a repository and allows the user to get the credentials needed to gain access. Institutions involved in the initial development of IIIF include Stanford University, Cornell University, and Los Alamos National Laboratory Research Library in the United States; the British Library and Bodleian Library in the United Kingdom; the National Library of France; and the National Library of Norway. The community of institutions currently involved with IIIF includes libraries, museums, and other cultural institutions managing digital image collections throughout the world.
OCLC has been phasing in support for IIIF over the last year. Support of the IIIF Image API was made available in the January 2017 release of the product. The IIIF Presentation API in CONTENTdm was included in its October 2017 release. No specific announcements have been made regarding adding support for the Search and Authentication APIs.
The extension of CONTENTdm to support IIIF enables libraries and other organizations using the product to access their images through many different viewers and tools beyond the product's own interface. OCLC notes that over 2,500 institutions have implemented CONTENTdm to manage their image collections and that the number of images across these collections totals over 30 million. Many of the libraries contributing to the Digital Public Library of America use CONTENTdm.
Apart from the recent IIIF support, CONTENTdm offers a robust set of its self-defined APIs to enable programmatic access to resources managed within an institution's repository. These APIs can be accessed through a wrapper called dmwebservices and include functions to make requests at the application, server, collection, or item level. An additional set of utility APIs support retrieval of specific images, thumbnails, streams, or files.
The digital asset management system that came to be known as CONTENTdm was originally created by the Center for Information Systems Organization (CISO) at the University of Washington. The software development lab behind the project was led by Greg Zick, who at the time was a Professor of Electrical Engineering for the university. One of the early projects of CISO involved working with the University of Washington Libraries to create a platform to manage a collection of 26,000 images related to theatre productions. The initial version of the software was launched in 1996. The success of the project led to interest outside of the university with some external implementations beginning in about 1999.
A new spin-off was launched in 2001, named DiMeMa, Inc., to commercialize the software, continue development, and provide support services. Greg Zick led the company as its president. Rather than develop its own extensive sales force, DiMeMa entered into a partnership with OCLC in June 2002 as its exclusive marketing and distribution channel for libraries. In August 2006, OCLC acquired CONTENTdm from DiMeMa, naming Zick as its new Vice President for Digital Services; in 2006, he shifted to Vice President of Global Engineering at OCLC, remaining in that role through June 2014.
CONTENTdm was originally offered as a system installed on servers housed in the local institution. In recent years, OCLC has primarily deployed new implementations of CONTENTdm as a hosted service, though the locally hosted versions continue to be supported. The implementation of IIIF reflects the ongoing efforts of OCLC to continue to develop and enhance this product.