The intersection of Archival Resource Keys (ARKs) and IIIF resources

Julien A. Raemy (University of Basel / DaSCH)
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IIIF Community Call | Wednesday, 25 January 2023

Background

Julien A. Raemy | ARKs and IIIF

ARKs and IIIF

  • Open communities that maintain standards/infrastructure
  • Prevalent in the Cultural Heritage field
  • Highly flexible in terms of associated metadata
  • No (direct) fees
Julien A. Raemy | ARKs and IIIF

IIIF Image API

It specifies a RESTful web service that returns an image in response to a standard HTTP(S) request.

  • Image Request
  • Image Information (JSON-LD)

https://iiif.io/api/image

Julien A. Raemy | ARKs and IIIF
Julien A. Raemy | ARKs and IIIF

IIIF Image API expressed via identifiers

[The identifier] may be an ARK, URN, filename, or other identifier.

The API places no restrictions on the form of the identifiers that a server may use or support. All special characters (e.g. ? or #) must be URI encoded to avoid unpredictable client behaviors. The URI syntax relies upon slash (/) separators.

Julien A. Raemy | ARKs and IIIF

IIIF Presentation API expressed via identifiers

While any HTTP(S) URI is technically acceptable for any of the resources in the API, there are several best practices for designing the URIs for the resources. (...) Once published, they should be as persistent and unchanging as possible.

https://iiif.io/api/presentation/3.0/#61-uri-recommendations

Julien A. Raemy | ARKs and IIIF
Julien A. Raemy | ARKs and IIIF

Congruence of ARK extensions and IIIF paths

  • ARK suffixes (extensions), which are used to refer to sub-objects in a hierarchy and to variant formats, are a natural fit for IIIF, with the Image API parameters expressed as path extensions.
  • Because ARKs permit suffix passthrough, it is possible to register just the top-level resolvable ARK to support an infinite number of resolvable suffix combinations.
Julien A. Raemy | ARKs and IIIF

Suffix Passthrough

Julien A. Raemy | ARKs and IIIF

ARKs and IIIF in practice

  • Many organizations use the ARK and IIIF specifications, sometimes in conjunction. Examples include the BnF, the British Library, Durham University Library, DaSCH, etc.
  • The application of ARKs within a IIIF ecosystem can go beyond the Image and Presentation APIs.
Julien A. Raemy | ARKs and IIIF

Some questions

Julien A. Raemy | ARKs and IIIF

Image Credits

Julien A. Raemy | ARKs and IIIF

URI Syntax (part 2) - Identifiers (part 3)

Suffix Passthrough makes every ARK the root of its own "namespace". Any provider-added (or user-added) suffix, which is a common way to form sub-object identifiers, will be passed through to the stored target object. For example, a dataset with X component parts and just this one "ancestor" ARK,