1. Department of Remote Sensing Science and Technology, School of Electronic Engineering, Xidian University, Xi'an, China
2. School of Computer Science and Engineering, North Minzu University, Yinchuan, China
3. Laboratory of Information Processing and Transmission, Institut Galilée, University Paris XIII, Villetaneuse, France
4. Academy of Advanced Interdisciplinary Research, Xidian University, Xi'an, China