1. Department of Electrical and Computer Engineering, Multimedia Understanding Group, Aristotle University of Thessaloniki, Thessaloniki, Greece
2. Centre for Research and Technology Hellas (CERTH), Information Technologies Institute, Thessaloniki, Greece
3. Department of Visitor Management and National Park Monitoring, Bavarian Forest National Park, Grafenau, Germany
4. Šumava National Park, Kašperské Hory, Czech Republic