1. College of Computer Science, Nankai University, Tianjin, China
2. Center for Machine Vision and Signal Analysis (CMVS), University of Oulu, Oulu, Finland
3. Aviation University of Air Force, Changchun, Jilin, China
4. Institute of Information Engineering, Chinese Academy of Sciences, Beijing, China
5. College of Electronic Science and Technology, Nation University of Defense Technology, Changsha, Hunan, China
6. Center for Machine Vision and Signal Analysis, University of Oulu, Oulu, Finland