Linking external Annotations targeting a Canvas to a Manifest

Use Case

You want to keep a resolvable link between annotations (contained in an external Annotation Page) and the Manifest containing the Canvases they are pointing at.

Usually, annotations in an external Annotation Page point to a Canvas or a Canvas fragment. This can cause problems for annotation consuming viewers as the Canvas identifier doesn’t have to resolve. To get the information from a Canvas a viewer needs access to the containing Manifest.

Implementation Notes

The Annotation Pages stored in an external JSON file contain a list of Annotations. While often the target of the annotations is an URL containing the identifier of the Canvas the target can also be a Specific Resource. The Specific Resource can have a source attribute containing the id pointing at the Canvas identifier and a partOf attribute pointing at the Manifest. Hence, the partOf attribute will contain the Manifest identifier in the id attribute, while the type attribute will be “Manifest”.

Restrictions

There is usually no advantage in using partOf attribute for pointing at Manifest with Annotations contained in a Manifest. In this case, it is implicit that they are about the Manifest containing them.

Example

The example is based on the recipe Embedded or referenced Annotations.

However, the target of the Annotation contained in the Annotation Page file will be a Specific Resource, which allows us to use a partOf attribute inside the source element to point at the original Manifest containing the Canvas. The partOf id attribute is the resolvable link of the Manifest.

In the example, it is also shown the usage of the selector attribute of the Specific Resource that allows us to select a region of the image using the value attribute of the Fragment Selector. The value attribute follows the Fragment Selector syntax [Fragment Selectors][0020].

Annotation Page file

JSON-LD

Manifest file

JSON-LD | View in Mirador | View in Annona | View in Glycerine Viewer | View in Theseus

Related Recipes

• Embedded or Referenced Annotations an Annotation Page without links to the original Manifest.
• Annotate specific images or layers Specific Resource used for annotating specific images or layers.
• Simple Annotation — Tagging for an Annotation using a Fragment Selector.
• [Fragment Selectors][0020] for understanding how to use a Fragment Selector.