As a result of recent progress in hardware and telecommunication technologies, the task of managing large amounts of image, video, audio data, or a combination of them, has become commonplace. A wide range of applications in areas such as content production and distribution, telemedicine, digital libraries, distance learning, tourism, distributed CAD/CAM, GIS, etc. rely on general purpose multimedia database systems. The relatively recent emergence of such applications is due to the rapid proliferation of the Web and improvements in encoding and transmission schemes. The usefulness of these applications is largely determined by their accessibility and portability and as such, multimedia data sets present a great challenge in terms of storing, querying, indexing and retrieval. To face such challenges it is not sufficient to just develop faster hardware or to design more sophisticated algorithms. Rather, a deeper understanding of the information at the semantic level is required. This results in a growing demand for efficient methods for retrieving semantic information and extracting knowledge from such content, since these are key enabling factors for the management and usability of multimedia content. The integration of knowledge technologies in such methods has been identified as one of the most promising approaches in order to efficiently address these issues.
Considering the above, there is a growing body of researchers investigating the convergence of multimedia and knowledge technologies, and a number of European collaborative, as well as nationally funded and commercial projects in this area. Recently, the aceMedia project and a W3C task force both started initiatives to seek greater interoperability and harmonisation in the areas of multimedia ontology development and multimedia annotation. It is an opportune moment to draw together appropriate strands of work from the multimedia, the knowledge and the integrated multimedia-knowledge domains to present a fundamental work which can serve as a reference book for researchers going forward. The main topics are integration of multimedia and Semantic Web technologies for describing, extracting and retrieving semantic information from multimedia coding enables a number of applications such as personalisation of multimedia content and personalised content adaptation.
There remains much confusion regarding the Semantic Web, what it is and what it can offer to industry and consumers. Material which provides practical use and applications is hard to find, so our book focuses on presenting the enabling technologies (ontologies and reasoning) and the practical applications (personalisation and content adaptation) that will help researchers, practitioners, and technologists discover benefits and issues relating to implementation of this new field. There are many open research issues and challenges, so we will focus on those which have reached a level of maturity sufficient to be explained and illustrated with examples and real results.