1. Centre for Telematics and Information Technology, University of Twente, Enschede, The Netherlands
2. Roessingh Research and Development, Enschede, The Netherlands
3. Roessingh Research and Development, Enschede, The Netherlands; Faculty of Electrical Engineering, Mathematics and Computer Science, University of Twente, Enschede, The Netherlands
4. Centre for Telematics and Information Technology, University of Twente, Enschede, The Netherlands; Philips Research, Department Information Processing Architectures, Sector Digital Lifestyle Technology of Philips Research,
Eindhoven, The Netherlands