1. Department of Computer Engineering and Informatics, University of Patras, Patras, Greece
2. IATE, University Montpellier, INRA, CIRAD, Montpellier SupAgro, Montpellier, France & INRIA GraphIK, LIRMM, Montpellier, France
3. Department of Computer Engineering and Informatics, University of Patras, Patras, Greece & CTI - Computer Technology Institute and Press “Diophantus”, Patras, Greece