- From: Yarden Katz <katz@underlevel.net>
- Date: Sun, 30 Mar 2003 19:12:20 -0500
- To: Dave Beckett <dave.beckett@bristol.ac.uk>
- Cc: www-rdf-interest@w3.org
Dave Beckett <dave.beckett@bristol.ac.uk> writes: >>>>Yarden Katz said: > > [Aside, this message probably didn't need cross posting ] Sorry, my bad, I meant to post only to www-rdf-interest. >> Hi, >> >> What are some approaches to assign MIME-types to certain RDF or DAML >> resources? For example, consider the following: >> >> <daml:ObjectProperty rdf:ID="Picture"> >> <rdfs:label>A Picture</rdfs:label> >> <rdfs:comment>A cute picture class in DAML</rdfs:comment> >> <rdfs:domain rdf:resource="#SomeObject"/> >> <rdfs:range rdf:resource="#????"/> >> </daml:ObjectProperty> > > I'm not familiar with the semantics of daml:ObjectProperty (or the > OWL equivalent), however ... > >> An agent attempting to render RDF data has no way of knowing that >> resources linked to using the above property are images and are to >> be handled as such. How can these meaning be conveyed in RDF? The >> obvious method seems to be to assign a MIME type such as >> "image/jpeg" as the range of this property, but I do not know how >> that can be expressed. Googling showed up a seemingly relevant link >> "Mapping Between Content-Types (MIME types) and URIs" from >> <http://rdfig.xmlhack.com/2001/05/09/2001-05-09.html> but it is >> broken. Any ideas you may have on how to attach this elementary >> problem would be great, whether involving usage of MIME or not. > > A quick google finds: > > Mapping between URIs and Internet Media Types > TAG Finding 8 April 2002 (Revised 27 May 2002) > > http://www.w3.org/2001/tag/2002/01-uriMediaType-9 As I pointed out in my original post: Googling showed up a seemingly relevant link "Mapping Between Content-Types (MIME types) and URIs" The W3C document you made reference to contains two broken links to IETF documents, one of which I mentioned above. > The other way uses familiar and well deployed Dublin Core vocabulary > an it's dc:format property. It takes as primary recommend value the > IMT / MIME Type as a literal. You might be able to do some inference > magic to imply that all your 'Picture's have the dc:format > "image/jpeg". Otherwise you'd need to put it in the instance data. Great! I never knew about this property of DC. However, I'm not quite sure I understand your suggestion about inferencing. As far as I can tell, I could use dc:format as follows: Given: <Picture rdf:resource="http://foo/bar.jpg"> <rdf:Description rdf:resource="http://foo/bar.jpg"> <dc:format>image/jpeg</dc:format> </rdf:Description> But I'm unsure of a way to express that "all resources pointed to by [i.e., everything in the rdfs:range] 'Picture' have dc:format of image/jpeg". If I hardcode it into the agent, well, then it's not really inferencing :) > See http://dublincore.org/documents/1999/07/02/dces/ > and many DC and RDF apps use this already. > >> >> I have a second question that's related to the above: is there some >> uniform way to note coordinates on an image (similar to an image >> map) in RDF? For example, expressing something a long the lines of >> "Instances of Object X should be placed in coordinate (X, Y)" The >> most relevant link I found was: >> <http://www.w3.org/2001/08/rdfweb/foafwho/imagemap/> but it does not >> show an RDF representation of an image map, only the plain HTML one. > > Sorry, I've no info on this question. > > Dave Thanks, -- Yarden Katz <katz@underlevel.net> | Mind the gap
Received on Sunday, 30 March 2003 18:40:45 UTC