1School of Automation, Northwestern Polytechnical University, Xi’an, Shanxi 710072, China 2Department of Electronics and Informatics (ETRO), Vrije Universiteit Brussel (VUB), Pleinlaan 2, 1050 Brussels, Belgium 3Department of Computer Engineering, Sejong University, Seoul 143-747, Republic of Korea 4Anhui Institute of Optics and Fine Mechanics, Chinese Academy of Sciences, Hefei, Anhui 230031, China 5Department of Electrical Engineering, National Taipei University of Technology, Taipei 10608, Taiwan 6Remote Sensing Signal and Image Processing Laboratory (RSSIPL), University of Maryland Baltimore County (UMBC), Baltimore, MD 21201, USA