1. Department of Photogrammetry and Remote Sensing, Faculty of Geodesy and Geomatics, K.N. Toosi University of Technology, Tehran 15433-19967, Iran
2. SFI Centre for Research Training in Machine Learning, School of Computer Science, University College Dublin, D04 V1W8 Dublin, Ireland
3. Department of Computing Science and Mathematics, University of Stirling, Stirling FK9 4LA, UK