1. National Technical University of Athens, Computer Vision and Photogrammetry Laboratory, Heroon Polytechneiou 9, 15780 Athens, Greece
2. University of Stuttgart, Institute for Photogrammetry, Geschwister-Scholl-Street, 24D, 70174 Stuttgart, Germany
3. Technical University of Crete, Computer Vision and Decision Support Laboratory, Kounoupidiana, 73100 Chania, Greece
4. 7reasons Ltd., Bäuerlegasse 4–6, 1200 Vienna, Austria