1. College of Electronic and Information Engineering, Machine Vision Engineering Research Center of Hebei Province, Hebei University, Baoding, China
2. Key Laboratory of Digital Medical Engineering of Hebei Province, College of Electronic and Information Engineering, Hebei University, Baoding, China
3. National Laboratory of Pattern Recognition, Institute of Automation, Chinese Academy of Sciences, Beijing, China
4. School of Computer Science and Technology, Henan Polytechnic University, Jiaozuo, China