During the last decade, multimedia has emerged as a major research and de velopment area. Pushed by advanced technology like huge-capacity storage de vices, fast networks, and powerful work stations, new applications have arisen. Many definitions of multimedia systems exist, one of them being computer sys tems that support interactive use of at least one of the following information sources: graphics, image, voice, sound, and video. These systems have caused a boom in the world of entertainment, but also in other business areas great opportunities for novel products and services are...