IIIF v3 canvas requires height+width and/or duration

[ndushay]

per http://prezi3.iiif.io/api/presentation/3.0/#canvas

A Canvas MUST have a rectangular aspect ratio (described with the height and width properties) and/or a duration to provide an extent in time.

It may be that IIIF v3 needs to relax this.

@blalbrit - can you speak to our object types / canvas needs?

types of objects, more or less (see https://docs.google.com/spreadsheets/d/1ud5kM_wNLAsRQCdkfqFtzZAwqRHHjE-dwTFh-QNw-sM/):

• file (???)
• citation (???)
• book (height + width?? is it avail?)
• document (height + width?? is it avail?)
• image (height + width - is it always avail?) example without: yv090xk3108
• audio (duration - do we always have this info avail? )
• video (height + width and duration - do we always have this info avail?)
• 3d object (height + width + depth - avail?)

[blalbrit]

@ndushay - I can start, but I think this is a larger conversation:

• file: expectation is download, what is the canvas in this situation? the thing on which a thumbnail could be painted? need input from editorial group on how to handle.
• citation: my thinking would be that, unless there is a thumbnail that could be painted on a canvas, there would be no IIIF representation.
• book: hxw for each image is available for each canvas and already represented in v2 manifests
• document: if no thumb available, we should seek info from editors - is an arbitrary hxw acceptable in IIIF land? (see https://dms-data.stanford.edu/data/manifests/v3test/bd742gh0511/manifest.json)
• image: hxw is available for each canvas and already represented in v2 manifests. The example provided is a document/document object,
  not image (https://argo.stanford.edu/view/druid:yv090xk3108)
• audio: duration, yes, we have this. There is needed work in the assembly robots to extract it.
• video: hxw & duration, yes, we have this. There is needed work in the assembly robots to extract it.
• 3d object: IIIF3 will not cover this. We are providing something that is completely non-spec to support 3d and it is not clear at all whether we'll have h, w, or z available - perhaps @snydman can weigh in on that.

[ndushay]

For file, we're currently serving out something: https://purl.stanford.edu/bd742gh0511/iiif3/manifest

[ndushay]

I added a note about this to https://github.com/sul-dlss/osullivan/wiki/Questions-about-IIIF-v3