1. Shenzhen Research Institute, Beijing Institute of Technology; Shenzhen 518057 China
2. College of Computer Science and Technology; Taiyuan University of Technology; Taiyuan 030024 China
3. Key Laboratory of Photoelectronic Imaging Technology and System of Ministry of Education, School of Optoelectronics; Beijing Institute of Technology; Beijing 100081 China
4. School of Information/Vision and Affective Science Integrated Laboratory; Research Institute, Kochi University of Technology; Kami Kochi 782-8502 Japan