Sonja Zillner

EMMA – A Query Algebra for Enhanced Multimedia Meta Objects

Enhanced Multimedia Meta Objects (EMMOs) are a novel approach to multimedia content modeling, combining media, semantic relationships between those media, as well as functionality on the media, such as rendering, into tradeable knowledge-enriched units of multimedia content. For the processing of EMMOs and the knowledge they contain, suitable querying facilities are required. In this paper, we present EMMA, an expressive query algebra that is adequate and complete with regard to the EMMO model. EMMA offers a rich set of formally-defined, orthogonal query operators that give access to all aspects of EMMOs, enable query optimization, and allow the representation of elementary ontology knowledge within queries. Thereby, EMMA provides a sound and adequate foundation for the realization of powerful EMMO querying facilities.

Integration of ontological knowledge within the authoring and retrieval of multimedia metaobjects

To enable efficient authoring, management and access to multimedia content, media data has to be augmented by semantic metadata and functionality. Semantic representation has to be integrated with domain ontologies to fully exploit domain-specific knowledge. This knowledge can be used within the authoring process and for the efficient management of multimedia content. Also, this knowledge can be used for refining ambiguous user queries by closing the conceptual gap between the user and the information to be retrieved. In our previous research, we have introduced Enhanced Multimedia Metaobjects (EMMOs) as a new approach for semantic multimedia meta modelling, as well as the query algebra EMMA, which is adequate and complete with regard to the EMMO model. This paper illustrates how ontological knowledge can be used within the authoring process of EMMOs, integrated into the EMMO knowledge structures and exploited for refining EMMA queries.

EMMA - towards a query algebra for enhanced multimedia meta objects

For efficient access to multimedia content the media data has to be enriched with additional information about the contents semantic description and functionality, e.g. style sheets for rendering. Current approaches for semantic modeling of multimedia content store the information about the contents semantics and functionality in different files and at different locations, which makes the retrieval and reuse of multimedia content very difficult. We have proposed enhanced multimedia meta objects (EMMOs) as a new means for semantic multimedia modeling that indivisibly combines multimedia content with its description and functionality. In this paper, we give an overview of the structure of EMMA, a query algebra, which is adequate and complete with regard to the EMMO model, enables query optimization, allows the integration of ontology knowledge, and supports distributive collaborative authoring.

The Design and Implementation of a Query Algebra of Multimedia Meta Objects

Enhanced multimedia meta objects (EMMOs) are a novel approach for the semantic modeling of multimedia content. For accessing the knowledge contained within EMMOs an adequate and efficient query mechanism is required. In this paper, we introduce the design and implementation architecture of EMMA, an expressive query algebra that is adequate with regard to the EMMO model and provides the basis for query rewriting and optimization

EMMA – a formal basis for querying enhanced multimedia meta objects

Todays multimedia content formats primarily encode the presentation of content but not the information the content conveys. However, this presentation-oriented modeling only permits the inflexible, hard-wired presentation of multimedia content. For the realization of advanced operations like the retrieval and reuse of content, automatic composition, or adaptation to a users needs, the multimedia content has to be enriched by additional semantic information, e.g. the semantic interrelationships between single multimedia content items. Enhanced Multimedia Meta Objects (EMMOs) are a novel approach to multimedia content modeling, which combines media, semantic relationships between those media, as well as functionality on the media (such as rendering) into tradeable and versionable knowledge-enriched units of multimedia content. For the processing of EMMOs and the knowledge they incorporate, suitable querying facilities are required. Based on the formal definition of the EMMO model, in this paper, we propose and formally define the EMMO Algebra EMMA, a query algebra that is adequate and complete with regard to the EMMO model. EMMA offers a rich set of orthogonal query operators, which are sufficiently expressive to provide access to all aspects of EMMOs and enable efficient query rewriting and optimization. In addition, they allow for the seamless integration of ontological knowledge within queries, such as supertype/subtype relationships, transitive and inverse associations, etc. Thus, EMMA represents a sound and adequate foundation for the realization of powerful EMMO querying facilities. We have finished the implementation of an EMMO container environment and an EMMA query execution engine, and are currently in the process of evaluating the query algebra in several case studies.