MPEG-7 Requirements to Highlight and Order Description Items

This document proposes some additional requirements to the MPEG-7 Requirements Document [2]. We think that some very important MPEG-7 requirements should deal with the concepts of (1) highlighting description items (e.g. images, sounds, events, objects etc.) which are most relevant to characterize a multimedia document and (2) of information ordering. In other words, due to a possible high amount of description items, an entity who will create descriptions of multimedia (MM) documents, according to MPEG-7 standard specifications (i.e. a description provider), shall highlight the items most representative for the kind of document being described in order to facilitate user needs (such as queries, navigation etc.). Besides, we consider the need of providing users with ordering mechanisms a very relevant issue to MPEG-7. Such ordering mechanisms can be derived by combining descriptor values (e.g., a set of key – frames ordered on the basis a color descriptor or a set of sounds ordered by means of their loudness descriptor). However the possible large variety of descriptors forming a description could consequently lead to a high number of ordering criteria for every description item of a subset of these items. Therefore we propose that the description provider should also highlight a reduced set of descriptors allowing to order some elements (e.g., key frames, events etc.) of a certain description in a proper manner for the MM document being described. The document is organized as follows: we explain the motivation behind our proposals in Section 2 and we present the new requirements in Section 3.