trifle performs all of the image server background tasks and also provides an interface for adding to the IIIF metadata to enhance the viewing experience. During the hilda ingestion the relevant information is assembled and sent to trifle, while jpeg2000 versions of the images are generated and sent to the image server. As schmit does, trifle relates images to collections and maintains the links with the catalogue description of the item digitised. It retains links to all the subordinate images within a digitised volume and the order in which they should appear and creates a basic IIIF manifest to publish this information. as a background process (currently overnight) all of this is sent to the image server and made public.
As well as the information about the book, trifle also provides access to the individual parts (images of each page) and any ranges that might have been created (such as separate works within a manuscript)
Rangs are a particularly useful element for understanding the structure of an online book, as they can be rendered by viewers as a table of contents and so enhance navigation. They are extremely tedious to create by editing the IIIF manifest text directly, so trifle provides an interface for creating them much more easily. It is possible to open the IIIF compliant viewer Mirador within trifle and use it as a visual editor for the manifest.
The left-hand column open in the Mirador viewer here represents an editable table of contents. The plus sign adds a new entry and then the thumbnail images of the relevant pages along the bottom of the viewer are selected and dragged over on to the entry to populate it. Entries can include the same image (items seldom end neatly in manuscripts) as other entries, and can be nested to multiple depths. The table of contents can then be saved and published as a new version of the manifest to the image server.