1. Hubei Key Laboratory of Optical Information and Pattern Recognition School of Optical Information and Energy Engineering Wuhan Institute of Technology Wuhan Hubei 430205 P. R. China
2. School of Electronics and Information Engineering Hubei University of Science and Technology Xianning 437100 P. R. China
3. National Engineering Research Center for Agro-Ecological Big Data Analysis & Application School of Electronics and Information Engineering Anhui University Hefei Anhui 230601 P. R. China
4. School of Optoelectronic Engineering Guangdong Polytechnic Normal University Guangzhou 510665 P. R. China
5. School of Physics and Technology Key Laboratory of Artificial Micro- and Nano-structures of the Ministry of Education and School of Physics and Technology Wuhan University Wuhan 430072 P. R. China