1. College of Computer Science and Software Engineering, Shenzhen University, Shenzhen, Guangdong 518060, China
2. Department of Medical Imaging, Suzhou Institute of Biomedical Engineering and Technology, Suzhou, Jiangsu 215163, China
3. College of Information Science and Engineering, Guilin University of Technology, Guilin, Guangxi 541004, China
4. School of Electronics and Information Engineering, Tongji University, Shanghai 200092, China