A Possible Extension of the Generic AV DS to Incorporate Highlighting and Ordering Functionalities

In this document, we propose an extension for the MPEG-7 Generic DS [2]. We believe that some important functionalities for MPEG-7, not yet addressed by the actual DS, should deal with the capability to (1) highlight description items (e.g. images, sounds, events, objects etc.) most relevant to the purpose for which a certain content description of a multimedia (MM) document has been created and (2) the capability of description information ordering. In other words, due to a possible large amount of description items, an entity who will create descriptions of multimedia (MM) documents, according to MPEG-7 specification (i.e. a description provider), shall highlight certain items most representative for the kind of document being described in order to facilitate user queries. Besides we consider the need of providing users with ordering mechanisms a very relevant issue for MPEG-7. Such ordering mechanisms are derivable from descriptors (e.g. a set of key – frames ordered on the basis a color descriptor or a set of sounds ordered by means of a loudness D). However a possible large variety in the types of descriptors composing a description could lead to a consequent high number of ordering criteria to arrange description items. Therefore we propose that the description provider should also select a reduced set of descriptors allowing to order a subset of description elements (e.g. key frames, events etc.) pertinent to the MM document being described. Our proposal consists in the incorporation in the current Generic Ds of two DSs covering the aforementioned functionalities. The document is organized as follows: in Section 2, we explain, after a quick overview of the current Generic DS, the motivation behind our proposals and in Section 3, we show the detailed structure of the DSs.