W3C Notes: RDF and XLink; Photo-RDF

The W3C Tech Reports page (http://www.w3.org/TR/) has a couple of new
RDF-related additions. Ron Daniel's "Harvesting RDF Statements from
XLinks" doc is now a W3C Note, alongside an updated version of the Yves
Lafon and Bert Bos Note on "Describing and retrieving photos using RDF
and HTTP". Nice work :-)

Both are backed up with code. Ron's note now includes an appendix, 
"Implementing the Harvesting in XSLT",http://www.w3.org/TR/xlink2rdf/#xslt
while the digital imaging note is accompanied by an opensource Java
implementation, RDFPic - http://jigsaw.w3.org/rdfpic/

As an aside regarding XSLT for XLink extraction, semantic web
screenscraping, RDF parsing etc., I recently stumbled across XSLTC,
and "XSLT to C++ Compiler". While I didn't manage to get the 0.4 release
to compile when I had a quick look yesterday, it does seem a promising
tool for speeding up XSLT-based apps. If anyone gets this running I'd love
to know how some of the RDF XSLT stuff compares in performance, in
particular the RDF/XSLT parsers. More information:
http://xmlhack.com/read.php?item=681 -> http://www3.cybercities.com/x/xsltc/


Details of the two W3C Notes follow below...

Dan


http://www.w3.org/TR/xlink2rdf/
W3C Note 29 September 2000
Editor: Ron Daniel Jr. (Metacode Technologies Inc.) <rdaniel@metacode.com> 

Abstract: [[
Both XLink [XLink] and RDF [RDF] provide a way of asserting
relations between resources. RDF is primarily for describing
resources and their relations, while XLink is primarily for
specifying and traversing hyperlinks. However, the overlap between
the two is sufficient that a mapping from XLink links to
statements in an RDF model can be defined. Such a mapping allows
XLink elements to be harvested as a source of RDF
statements. XLink links (hereafter, "links") thus provide an alternate
syntax for RDF information that may be useful in some situations. 

This Note specifies such a mapping, so that links can be
harvested and RDF statements generated. The purpose of this
harvesting is to create RDF models that, in some sense,
represent the intent of the XML document. The purpose is not to
represent the XLink structure in enough detail that a set of
links could be round-tripped through an RDF model. 
]]



http://www.w3.org/TR/photo-rdf/
Describing and retrieving photos using RDF and HTTP
W3C Note, 28 September 2000
Authors: 
	Yves Lafon, W3C, ylafon@w3.org
	Bert Bos, W3C, bert@w3.org 
Abstract: [[
This note describes a project for describing & retrieving
(digitized) photos with (RDF) metadata. It describes the RDF schemas,
a data-entry program for quickly entering metadata for large
numbers of photos, a way to serve the photos and the metadata
over HTTP, and some suggestions for search methods to retrieve
photos based on their descriptions.

The data-entry program has been implemented in Java, a
specific Jigsaw frame has been done to retrieve the RDF from the
image through HTTP. The RDF schema uses the Dublin Core schema
as well as additional schemas for technical data.
]]

See also:
http://www.w3.org/TR/photo-rdf/#dlsoft
->http://jigsaw.w3.org/rdfpic/

[[
RDFPic is a tool to embed an RDF description of a picture into the
picture itself, as described by Describing and retrieving photos using
RDF and HTTP. 

The source code and documentation is available, as well as a
ready-to-run jar file (java 1.2 or better is needed). 
]]

Received on Saturday, 30 September 2000 09:22:17 UTC