Description
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.
Processing expectations
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.
Future ChangesChildren
The following elements occur in ImageObjectCO: AreaSpec, CalloutList, ImageObject.
In some contexts, the following elements are allowed anywhere: BeginPage, IndexTerm.