IIIF API Support in CONTENTdm
The International Image Interoperability Framework (IIIF) is a community effort among the world’s leading research libraries and image repositories to collaboratively produce an interoperable technology and community framework for image delivery.
OCLC and CONTENTdm are part of this community effort and are adding support for the APIs defined by IIIF. CONTENTdm repositories running an up-to-date version now have full support for the IIIF Image and Presentation APIs for all image-based records.
Working with the IIIF Image API
Here is an example CONTENTdm image record that utilizes the IIIF Image API for the image display:
https://sandbox.contentdm.oclc.org/digital/collection/coll16/id/357
To verify that a CONTENTdm image is supported by the IIIF Image API, a request can be made to return a JSON document providing image information, including width, height, and scaling information.
This CONTENTdm image information URL pattern follows the IIIF Image API specification:
{base CONTENTdm URL}/digital/iiif/{CONTENTdm collection alias}/{Record identifier}/info.json
For the example record noted above, the "info.json" URL is
https://sandbox.contentdm.oclc.org/digital/iiif/coll16/357/info.json
The IIIF Image API is a powerful and flexible service for interaction with digital images. For example, here's a request to generate a JPEG of the entire image at 25% zoom:
https://sandbox.contentdm.oclc.org/digital/iiif/coll16/357/full/pct:25/0/default.jpg
And here's another request, showing a selected detail from the full image:
https://sandbox.contentdm.oclc.org/digital/iiif/coll16/357/1500,1000,1200,1400/pct:25/0/default.jpg
And one more example, showing the image resized for use as a thumbnail image:
https://sandbox.contentdm.oclc.org/digital/iiif/coll16/357/full/150,/0/default.jpg
For more information on these and other methods for calling the CONTENTdm IIIF Image API service, please consult the IIIF Image API specification.
Working with the IIIF Presentation API
Here is an example CONTENTdm image record that support a IIIF Presentation API response:
https://sandbox.contentdm.oclc.org/digital/collection/coll16/id/357
And here is the IIIF Presentation API call that returns the JSON manifest:
https://sandbox.contentdm.oclc.org/digital/iiif-info/coll16/357
CONTENTdm's Presentation API request URL follows the pattern described in the IIIF Presentation API specification:
{base CONTENTdm URL}/digital/iiif-info/{CONTENTdm collection alias}/{Record identifier}
For more information on these and other methods for calling the CONTENTdm IIIF Presentation API service, please consult the IIIF Presentation API specification.
A note about HTTPS
CONTENTdm's IIIF API functionality supports HTTPS requests. As long as the URL being requested is at oclc.org, both the Image and Presentation API requests will automatically redirect to HTTPS. This allows you to include IIIF calls directly in your other content served over HTTPS.