VEP-011: datalink/core#thumbnail

[ada nebot]

Hi Markus,

I wonder what the difference between preview and thumbnail is. In other words: when is one used against the other? when is a small preview considered a thumbnail? Also, does it make any real difference in the behaviour of a client? 

I call thumbnails to small things, but are previews of finding charts for instance thumbnails? For instance, do ZTF or LSST reference images (in whatever format) belong to this category? 

I see that preview is parent of thumbnail so I guess it is up to the data providers to use one or the other and for the client it doesn’t make much of a difference, right? 

Cheers,
Ada


> On 2 Dec 2021, at 11:49, Markus Demleitner <msdemlei at ari.uni-heidelberg.de> wrote:
> 
> Dear Semantics WG, dear DAL,
> 
> We have another proposal for a new term in datalink/core:
> 
> Vocabulary: http://www.ivoa.net/rdf/datalink/core
> Author: pdowler.cadc at gmail.com
> Date: 2021-10-18
> 
> Term: thumbnail
> Action: Addition
> Label: Small Graphical Representation
> Description: A very small preview suitable for displaying many at one time
> Relationships: rdfs:subProperyOf(preview)
> Used-in: https://ws.cadc-ccda.hia-iha.nrc-cnrc.gc.ca/caom2ops/datalink?ID=ivo://cadc.nrc.ca/BLAST?BLASTabell31122006-12-21/REDUCED_250_2009-03-06
> 
> Rationale: The term is used to specify that the link target is a small
> preview suitable for displaying many such "thumbnails" at one time. The
> primary use case is for a user interface to load or display these in a
> table or as a popup, usually one per row but a grid of thumbnails might
> be useful as well.
> 
> This is used in the CADC AdvancedSearch user interface as a popup when
> users mouse over the preview links and allows the application to load
> many of these at once. Example (BLAST + calibrated image query): 
> 
> https://www.cadc-ccda.hia-iha.nrc-cnrc.gc.ca/en/search/?Observation.collection=BLAST&Plane.calibrationLevel=2
> 
> (or in VCS at
> <http://volute.g-vo.org/svn/trunk/projects/semantics/veps/VEP-011.txt>)
> 
> Opinions?  Endorsements?
> 
> Thanks,
> 
>           Markus