Information Technology Reference
In-Depth Information
An important point to notice here is that webble annotations describe only
webbles and their slots. Indeed, the example annotation of Figure 3 does not
say anything about the image
http://a/b/c.jpeg
displayed by the image web-
ble
wi
. In other words, webble annotations in this figure annotate only media
containers
and do not annotate media
contents
.
2.2 Annotating Slot Values
To annotate media contents, our approach uses an entailment rule to
infer
anno-
tations of media contents from annotations of media containers and their state.
In other words, our framework assumes that metadata of a media content is
represented as state of a media container. Regarding the webble architecture,
the state of a webble is externalized as a set of slot values.
An(wm)
=
{
(dc:title, "Metadata"), (rdf:type, DublinCoreWebble),
(wb:hasSlot, wm:#url), (wb:hasSlot, wm:#title), ...
}
{
(dc:title, "URL"), (rdf:type, TextSlot),
(wb:hasValue, "")
}
An(wm:#title)
=
{
(dc:title, "Title"), (rdf:type, TextSlot)
}
(wb:represents, dc:title), (wb:annotatesValueOf, wm:#url),
(wb:hasValue, "La Joconde")
An(wm:#url)
=
}
... ... ...
Fig. 4.
Slot value annotation example
Figure 4 shows an example annotation of DublinCoreWebble
wm
and its slots
(only annotations of
url
slot and
title
slot are shown).
The properties
wb:represents
and
wb:annotatesValueOf
in the annotation
of
title
slot are terms from the webble vocabulary used for annotating
values
of slots. Intuitively, the annotation of
title
slot says that “the value of
title
slot represents
dc:title
of something specified by
url
slot”.
This statement is represented by three terms of webble vocabulary and one
entailment rule. Figure 5 illustrates the mechanism of slot value annotation.
In this figure,
wb:represents
associates slot
t
with an attribute name
p
.
p
v
s
v
t
wb:
hasValue
wb:
hasValue
wb:annotates
ValueOF
wb:represents
p
s
t
Fig. 5.
wb:represents
and
wb:annotatesValueOf
