Image Open Access: Implementing IIIF in CONTENTdm

CONTENTdm is a complete digital collection management software solution. It offers libraries, museums, curators and institutions the ability to build, preserve and showcase their digital collections. The latest release of CONTENTdm introduced support for the International Image Interoperability Framework (IIIF) Image API version 2.1.  

IIIF is a standard that allows images to be interoperable on the web so that they can be shared across institutions and used in a variety of exciting ways. IIIF was created by a community of the world’s leading cultural heritage institutions. This community develops shared APIs, implements them in software, and exposes interoperable content. Further, IIIF is a global framework for images from any institution to be delivered in a standard way.  

The impact of CONTENTdm and IIIF  

By supporting IIIF, CONTENTdm adds approximately 20 million images from more than 1,000 repositories to the IIIF universe, helping to bring “critical mass” to IIIF. In addition, a large number of Digital Public Library of America (DPLA) contributors are using CONTENTdm, which can also help DPLA reach the critical mass needed to support IIIF.  

IIIF enables CONTENTdm and OCLC to 

• offer optimized image functionality,

• join an interoperable global cultural heritage community,

• use existing plug-and-play software like OpenSeadragon (see below), and 

• enable annotation and other emerging uses in the future.

IIIF enables CONTENTdm users to

• have speedy access to images hosted in CONTENTdm,

• use easy-to-use viewers to zoom and pan,

• access CONTENTdm images in any IIIF compatible software, and

• mix and match CONTENTdm image resources with those from other providers.

CONTENTdm is widely used by those who wish to do extensive customizations, but it is also very popular for use off the shelf by those who don’t have the resources for customization. Therefore, by supporting IIIF natively, CONTENTdm helps bring interoperability to those institutions who do not have the resources to implement it themselves.

Using OpenSeadragon in CONTENTdm

OpenSeadragon implementation in CONTENTdm

OpenSeadragon is an open-source, web-based viewer for high-resolution zoomable images. The OpenSeadragon viewer is now available on CONTENTdm hosted websites, bringing a much faster, smoother viewing experience to the software. IIIF is the building block that allows this modern viewer to operate.

To try OpenSeadragon in CONTENTdm, visit this item in the CONTENTdm Sandbox and click on the expand icon in the upper right hand corner of the image.

Accessing IIIF images available via CONTENTdm

IIIF images in CONTENTdm can be accessed using the following syntax:

{YourCONTENTdmWebsiteURL}/digital/iiif/{collectionAlias}/{item ID}/{region}/{size}/{rotation}/{quality}.{format}

More information on IIIF URI syntax is available at http://iiif.io/api/image/2.1/ - uri-syntax.  

All unrestricted images in CONTENTdm are now available via the IIIF Image API by default. However, CONTENTdm administrators can choose not to have their images made publicly available via IIIF by using CONTENTdm’s Website Configuration Tool.

Next steps

Next up for CONTENTdm is work to support the IIIF Presentation API. The Presentation API “allows the structure and layout of a complex image-based object to be made available in a standard manner. Many different styles of viewer can be implemented that consume the information to enable a rich and dynamic experience, consuming content from across collections and hosting institutions.” However, this presents a challenge in CONTENTdm. CONTENTdm has a proprietary data structure for compound objects that is used in a number of diverse ways. This data structure is not compatible with the Presentation API without modification.

An example of the CONTENTdm compound object structure in XML

We are working internally with our development and research teams to solve this. When we get there, we hope to expand the functionality we can offer in CONTENTdm by using the Presentation API to incorporate further functionality enabled by IIIF, such as citation and annotation. We also hope to allow CONTENTdm images to be used in software like Mirador, an open-source, web-based, multi-window image viewing platform with the ability to zoom, display, compare and annotate images from around the world.