1. Department of Electronics and Information Systems, Multimedia Lab, Ghent University—IBBT, Gaston Crommenlaan 8 bus 201, B-9050 Ledeberg-Ghent, Belgium
2. APEM Computing Lab, Centre for Innovation & Enterprise, Begbroke Science Park, University of Oxford, Begbroke Hill, Woodstock Road, Begbroke, Oxfordshire, OX5 1PF
3. Department of Electronics and Information Systems, Multimedia Lab, Ghent University—IBBT, Gaston Crommenlaan 8 bus 201, B-9050 Ledeberg-Ghent, Belgium, ,