MPEG‐7/21: Structured Metadata for Handling and Personalizing Multimedia Content

In recent years the variety of different multimedia devices, as well as the amount of available multimedia content, has dramatically increased. To serve multimedia consumers according to their needs, personalization aspects are essential. For this MPEG‐7/21 offers a variety of possibilities to describe user preferences, terminal capabilities and transcoding hints within its ‘Digital Item Adaptation’ part. User preferences include information about the specific user, for instance what movie genre he/she prefers. Terminal capabilities describe the user's client device, like e.g. the maximal possible display resolution. In the transcoding hints the authors of multimedia content can define adaptation constraints regarding, e.g., minimum video size, etc. This chapter investigates the provided user preference model and discusses necessary extensions to provide overarching preference descriptions. Currently in the community basically three main approaches are discussed: usage of semantic Web languages & ontologies, XML databases & query languages, or more expressive preference models.