    | DocBook: The Definitive Guide 2.0.17 (Alpha) |
| | DocBook: The Definitive Guide 2.0.17 (Alpha) |
$Revision: 1666 $
$Date: 2002-06-12 07:19:37 -0400 (Wed, 12 Jun 2002) $
imageobjectco — A wrapper for an image object with callouts
Callouts, such as numbered bullets, are an annotation mechanism. In an
online system, these bullets are frequently “hot,” and clicking on
them navigates to the corresponding annotation.
A ImageObjectCO is a wrapper around an AreaSpec and
an ImageObject. An AreaSpec identifies the locations
(coordinates)
on the image where the Callouts occur.
The ImageObjectCO may also contain the list of annotations in
a CalloutList, although the CalloutList may also
occur outside of the wrapper, elsewhere in the document.
Formatted as a displayed block. It may not be rendered at all, depending on its placement
within the MediaObject that contains it and
the constraints on the publishing system. For a more detailed description
of the semantics involved, see MediaObject.
The mandatory processing expectations of a ImageObjectCO are
minimal: a system is expected to render the image, if possible, and the
callout list, if present.
In online environments, the processing system may be able to instantiate the linking relationships between the callout marks on the image and the annotations. For example, an HTML presentation system might use the coordinate information to construct a client-side image map. Some processing systems may even be able to go a step further and generate the callout marks automatically from the coordinate information. But this level of sophistication is not mandatory.
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| imageobject | | important |