Page 151 - Building Digital Libraries

CHAPTER 6

image interaction) was developed and largely adopted in the early 2000s, the
implementations of the readers, the APIs utilized to render and call images,
were largely proprietary. This made it very difficult for scholars to utilize
content from disparate systems, and stunted the ability of digital humanities
scholars who were interested in comparing, searching, or analyzing large
swaths of image data. IIIF was developed to solve this issue. IIIF’s image
protocol defined a common set of parameters, allowing systems to represent
their images as JSON objects. This allowed the library community and those
external to the library community to develop common methods of consum-
ing image content, leading to the development of tools like Mirador or the
Universal Browser, which co-opt the OpenSeadragon project to provide
an open-source, easy-to-use image-rendering and manipulation viewer.
The development of the IIIF standard, and the viewers that could utilize
the standard, opened new veins of research. Archivists now had ways to
re-create long-lost manuscripts digitally by leveraging the IIIF framework
to create their own digital editions, and humanities scholars were able to
develop tools that could mine and interact with digital library systems sup-
porting IIIF easily. Below, I’d like to specifically highlight the IIIF image and
presentation schemas.

iiiF image Schema
The IIIF Image schema is the oldest and best-established IIIF format. The
Image schema provides a JSON representation of an image object, which
can then be used by an image viewer to render and interact with the object
on the system—enabling libraries to encourage the embedding of digital
content, while still maintaining control of the digital asset.
Figure 6.9 demonstrates how an image may be represented utilizing the
IIIF Image schema. In addition to defining how an image object might be
represented, the schema provides a common language for requesting data
from IIIF-enabled image servers. This allows repositories to respond to a
common set of instructions, and it allows users to request full or scaled
images, as well as full or specific regions. The protocol standardizes image
rendering and manipulation, providing interoperability between a wide
range of images being served via IIIF-enabled servers.

iiiF Presentation Schema
The IIIF Presentation schema provides a method for digital library systems
to define the structure of a digital object. Whether this structure is repre-
sented as a monograph (with a table of contents) or a collection, or a set of
digital objects, the IIIF Presentation schema provides systems with a method
to represent the physical structure and relationships of a set of objects. If
this sounds familiar, it should, since the IIIF Presentation schema’s goals
mirror the same goals found with METS. Unlike METS, however, IIIF’s
Presentation schema is very lightweight and is developed to be action-
able. Utilizing JSON, the IIIF Presentation schema can be consumed and
processed by most current-generation programming languages and tool

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