1. School of Automation, Chongqing University of Posts and Telecommunications, Chongqing 400065, China
2. Key Laboratory of Optoelectronic Technology & Systems, Ministry of Education, Chongqing University, Chongqing 400044, China
3. College of Forestry, Henan Agricultural University, Zhengzhou 450002, China
4. College of Computer Science and Technology, Chongqing University of Posts and Telecommunications, Chongqing 400065, China