Improve display of citation-only images

[andrewjbtw]

The "citation-only" rights setting means that only metadata is available to the public. For items with still imagery, metadata includes a thumbnail with a maximum size of 400px on the long-edge. (See the SUL policy on Use of Thumbnail Digital Images in Online Initiatives.)

This presents a challenge for display because it results in the viewer showing blurry images for citation-only objects. (Example.) We also don't have any public-facing message on the image and book viewers indicating when rights are restricted. Over the years, we've received numerous messages from users expressing a mix of confusion and frustration with citation-only objects.

We have yet to work on designs to address this problem but I'm filing an issue here because it tends to get lost in the sw- and purl-feedback queues. A new design is likely to address:

• The display itself. Could we show a thumbnail that is not blurred, possibly including turning off dynamic zoom capability?
• Restriction messaging. We do now have restriction messages in the media viewer, which could be a model for other viewers.

There was some discussion in 2021-2022 about proposing a change to the thumbnail policy to allow larger thumbnails, but I don't think that has gone forward. We may still pursue that but I think it's likely we'll continue to have to work with the 400px restriction for years.