Thanks, Stefano. The example of the Getty is very useful.
As for placing IIIF manifests for wiki articles into IIIF collections,
you're right, I had overlooked this.
It's a good idea -- though for Wikimedia there may be a wrinkle, that
I'll come to below.
To think about its relevance for Wikimedia, it is probably useful to
take Commons and the Wikipedias separately.
For Commons, it's a good idea but its relevance is limited, because
there are rather few articles ("galleries") - I think the figures
currently are about 70,000 galleries on Commons, compared to about 9
million categories.
So for Commons (which is where high-resolution images contributed by
partner institutions would normally be hosted), to make the images
discoverable at scale by IIIF tools, I do see the main way forward as
via a manifest of the all images in the Commons category.
If one also had a IIIF collection for the category, that could contain
that main manifest, any other manifests associated with the category;
plus collections representing sub-categories of that Commons category,
to capture the hierarchical structure of the Commons category tree.
So, yes, that would be a very natural place also for manifests for any
Commons galleries associated with the category, as you suggest; even if
it would only be the occasional category that would have such a gallery
(and most galleries have not been maintained, so might not contain the
best pictures, and sometimes/often not even the best version of a
particular picture).
Compared to Commons, the situation on Wikipedias is reversed, in that
articles rather than categories are the objects that are most important,
most visible, and most curated.
However there is an additional issue with the Wikipedias (most of them
anyway), namely fair-use images (eg record covers, company logos, etc,
and certain other non-free copyright images, all typically limited to
only about 300 x 300 pixels).
Legally the making available of the fair-use images is only justified by
their contextual relevance in the articles which contain them. So I am
a little wary about any readiness with which they would be made
available, if the proximity to that context became more remote.
I do think that an "IIIF manifest" link in the sidebar of every
Wikipedia article would be the best way to advertise any IIIF image API
capability on the platform, if it becomes available; and indeed to
highlight IIIF and its possibilities as a whole to users. So it would
be nice to see such links appearing early.
But on the other hand, to put off till later any issues involving
fair-use content, parhaps the initial IIIF collection hierarchy should
just focus on Commons, at least to start with.
One way round might be for manifests for Wikipedia articles to only
include the content in them drawn from Commons. (Which might be an
initial development stepping-stone anyway).
But the right way forward after that might take some thinking about.
Would it be confusing if manifests for an article did not present all of
the content from that article, but only the free content? Would it
instead be more useful and intuitive if the manifests instead contained
all the content (including the non-free content), but then were not
gathered into collections? If the largest images were discoverable
through IIIF collections for Commons categories, would it matter if
there were not collections for the Wikipedia article manifests? Or
perhaps I am over-thinking this, and such a degree of caution about
non-free images is just unneeded pernicketiness? I am not sure.
But whatever eventual way forward, I do think an IIIF collection
hierarchy for Commons would be a good start.
And by adding the capability to MediaWiki for that use, that should also
make at least the capability available for third parties running their
wikis on Mediawiki, to use as they want. So with luck that should be
3rd parties too, making IIIF manifests and IIIF collections available,
derived from their wikis.
So yes, the capability for manifests derived from wiki articles to then
appear in collections relating to wiki categories is definitely worth
remembering, and I hope would indeed be useful.
Thanks again,
James.