Introduction to the International Image Interoperability Framework (IIIF)
The main goal of IIIF is to construct an interoperable way to standardize the delivery of images from external servers to several digital environments on the Web where they can be viewed, compared, annotated and interacted with in many other ways. For further information the IIIF Community delivers a handy introduction and additional information material.
The framework was founded in 2011 with support from the Mellon Foundation through a joint initiative of renowned Cultural Heritage Institutions (CHI) including Harvard University, Stanford University Libraries, Cornell University, the British Library, the Bodleian Library and the national libraries of France and Norway. In 2015, the IIIF Consortium, managing and developing the framework, was formed by 11 institutions. Although the origins of IIIF lie in the library sector, by now there are various different CHIs partaking in the community and developing the standard. Under the following link you can find a list of the community members who work with IIIF and try to enhance its usage in the scientific community.
IIIF stands for International Image Interoperability Framework (spoken Triple-Eye-F). It was created to offer the scientific community a way to productively interact with their digital objects (visual or audio/visual) and use them across different platforms. The framework consists of different APIs (Application Programming Interface) that supplement each other and specify the way a user can work with the digital resources. When implementing IIIF one starts with the Image API. It is the basis of the framework and the other APIs build upon it. At the moment the IIIF community offers the following APIs:
- Image API
- Presentation API
- Content Search API: enables search queries within an IIIF resource
- Authentication API: allows to regulate access to IIIF resources
- Change Discovery API: provides information about object changes (creation, modification, and deletion) within IIIF resources
- Content State API: generates links to objects in certain states
The highlighted APIs are most important and will be described in detail in the following paragraphs.
The Image API
For the images to be delivered in the correct way, IIIF offers the Image API. The interface gets the images from an Image Server that can either be maintained by the institution that offers the images, or by an external host. It defines how pixels are delivered to a viewer. In that manner it allows the pixels to be modified, the image to be changed for enhancing research activities.
The Image API stands for itself and can be used without the Presentation API that will be further explained in the following paragraphs. Through the Image API the image can be modified in sense of choosing a specific region, viewing the image in a smaller or bigger size, rotating and changing the colour of the image. The IIIF Community offers an Image API playground to learn the functionalities and how to make changes.
The Presentation API
If you want to go one step further concerning how you can view and modify your images, the IIIF Community offers the Presentation API. It attaches basic metadata and structure to digital objects and specifies how they are viewed in an image viewer. There are several open source image viewers that can be used for your own projects. In the IIIF workshop, that allows you to learn in your own pace, two viewers are recommended to begin with: Mirador and Universal Viewer.
The Presentation API works via a so-called Manifest, a JSON file that bundles all the information needed for the viewer, like which images are included, which metadata and information you want to add and how you want the different images to be ordered (if your manifest contains several pages/images). There are many products online that help at building manifests for your digital objects.
Once the manifests are ready, their URI can be put into e.g. one of the before-mentioned viewers where they can then be viewed, modified and compared.
The following link is the URI to the manifest of a herbarium specimen of the Royal Botanic Garden Edinburgh (Carex pallescens L.). This shows how a Manifest-Link usually looks like. This link, as mentioned above, can easily be put into one of the viewers.
IIIF and the Natural History Community
As explained in the video above, IIIF plays an important role in the future development of the Natural History Community and the research connected to it. The video also mentions how IIIF is built through the two APIs, the Image API and the Presentation API. There are some additional APIs, but for the basic structure of IIIF there are only those two needed.
The IIIF Community itself offers various guides and documentations online:
- Get started Guides: Browse individually concerning your specific needs
- 5-day Online Workshops: register for the next workshop
- Workshop Recording: learn at your own pace
- For further reading there are also some Non-English IIIF Resources available
Europeana as a platform for cultural heritage actively enhances the usage of IIIF. Therefore, it also offers further learning material: