An Adaptation Framework For Web Multimedia Presentations

A multimedia document is composed of several media-objects that are presented to user/application with respect to certain spatio-temporal relationships defined over them (called also multimedia presentation). In Web environments, those media objects could be located onto different servers and hence pose the problem of delivering multimedia documents with respect to those constrains. In many situations, it is not always possible to support the presentation spatio-temporal constraints. This is due to noisy problems such as low bandwidth, or user preferences/profile as the lack of audio devise. One interesting alternative consists in adapting the presentation by substituting media elements by others media that are semantically equivalent. This adaptation is not obvious and could lead, if it is not carried out carefully, to a misunderstood presentation. This paper deals with the problem of finding adequate multimedia presentation that fulfils spatio-temporal constraints. More precisely, we first propose a spatio-temporal algebra for the composition of multimedia presentations. Secondly, we present a semantic adaptation strategy by means of substitution of media elements that preserves presentation semantics.