Linked Art API: Digital Object

Introduction

The Digital Object API is a method of getting access to descriptions of digital content, such as images, documents or other electronic media, regardless of whether that file is accessible over the network at all. Access to the digital content itself, when it is available online, is provided through the access_point property within the description. The Digital Object API is of average complexity with many familiar properties and patterns, plus several additions to describe the object's relationship to other entities.

For more information about the usage of Digital Object records, please see the Digital model description.

Property Definitions

Dereferencing an entity via the Digital Object endpoint would result in a JSON-LD document containing a single JSON object with the following properties.

Properties of Digital Objects

Properties of Digital Services

Property Diagram

JSON Schema

See the schema documentation and the schema itself

Incoming Properties

Digital Object instances are typically found as the object of the following properties, other than the self-referential properties above. This list is not exhaustive, but is intended to cover the likely cases where other endpoints refer to digital objects.

Example

The JSON for a Digital Object entry for a digital image of a self-portrait by Van Gogh could be as below.

• It has the Linked Art context document reference in @context
• It self-documents its URI in id
• It has a type of "DigitalObject"
• It has a _label with the value "Digital Image of Self-Portrait of Van Gogh" for people reading the JSON
• It is classified_as a "Digital Image", which has an id of "aat:300215302"
• It is identified_by ...
  • ... a Name, with the content "Self-Portrait Dedicated to Paul Gauguin"
  • ... and an Identifier, with the content "47174896", which is classified_as an Owner-Assigned number
• It has two Dimension entries ...
  • ... a height ("aat:300055644") of 2550 pixels ("aat:300266190")
  • ... a width ("aat:300055647") of 2087 pixels ("aat:300266190")
• It is a member_of a Set of Van Gogh self-portraits (possibly both digital and physical)
• It is available to be retrieved from the URI in access_point
• It has a media type (or MIME type) of "image/jpeg"
• It digitally_shows the same visual content as the physical painting
• It is part_of another Digital Object, in this case a IIIF Manifest
• It is digitally_available_via a Digital Service which ...
  • ... conforms_to the IIIF Image API
  • ... is available to be interacted with at the URI in access_point
• It was created_by a Creation which ...
  • ... was carried_out_by the Harvard Art Museums
  • ... used_specific_object of the physical painting

{
  "@context": "https://linked.art/ns/v1/linked-art.json",
  "id": "https://linked.art/example/digital/0",
  "type": "DigitalObject",
  "_label": "Digital Image of Self-Portrait of Van Gogh",
  "classified_as": [
    {
      "id": "http://vocab.getty.edu/aat/300215302",
      "type": "Type",
      "_label": "Digital Image"
    }
  ],
  "identified_by": [
    {
      "type": "Name",
      "content": "Self-Portrait Dedicated to Paul Gauguin"
    },
    {
      "type": "Identifier",
      "classified_as": [
        {
          "id": "http://vocab.getty.edu/aat/300404621",
          "type": "Type",
          "_label": "Owner-Assigned Number"
        }
      ],
      "content": "47174896"
    }
  ],
  "dimension": [
    {
      "type": "Dimension",
      "classified_as": [
        {
          "id": "http://vocab.getty.edu/aat/300055644",
          "type": "Type",
          "_label": "Height"
        }
      ],
      "value": 2550,
      "unit": {
        "id": "http://vocab.getty.edu/aat/300266190",
        "type": "MeasurementUnit",
        "_label": "pixels"
      }
    },
    {
      "type": "Dimension",
      "classified_as": [
        {
          "id": "http://vocab.getty.edu/aat/300055647",
          "type": "Type",
          "_label": "Width"
        }
      ],
      "value": 2087,
      "unit": {
        "id": "http://vocab.getty.edu/aat/300266190",
        "type": "MeasurementUnit",
        "_label": "pixels"
      }
    }
  ],
  "member_of": [
    {
      "id": "https://linked.art/example/set/0",
      "type": "Set",
      "_label": "Images of Self-Portraits of Van Gogh"
    }
  ],
  "access_point": [
    {
      "id": "https://ids.lib.harvard.edu/ids/iiif/47174896/full/full/0/default.jpg",
      "type": "DigitalObject"
    }
  ],
  "digitally_shows": [
    {
      "type": "VisualItem",
      "_label": "Visual Content of Self-Portrait of Van Gogh"
    }
  ],
  "format": "image/jpeg",
  "digitally_available_via": [
    {
      "type": "DigitalService",
      "_label": "IIIF Service",
      "access_point": [
        {
          "id": "https://ids.lib.harvard.edu/ids/iiif/47174896",
          "type": "DigitalObject"
        }
      ],
      "conforms_to": [
        {
          "id": "https://iiif.io/api/image/2/context.json",
          "type": "InformationObject"
        }
      ]
    }
  ],
  "created_by": {
    "type": "Creation",
    "carried_out_by": [
      {
        "id": "https://linked.art/example/group/harvardartmuseums.org",
        "type": "Group",
        "_label": "Harvard Art Museums"
      }
    ],
    "used_specific_object": [
      {
        "id": "https://harvardartmuseums.org/collections/object/299843",
        "type": "HumanMadeObject",
        "_label": "Self-Portrait of Van Gogh"
      }
    ]
  },
  "part_of": [
    {
      "id": "https://iiif.harvardartmuseums.org/manifests/object/299843",
      "type": "DigitalObject",
      "_label": "IIIF Manifest"
    }
  ]
}