1. College of Mathematics and Computer Science, Zhejiang A&F University, Hangzhou 311300, China
2. Key Laboratory of Forestry Intelligent Monitoring and Information Technology of Zhejiang Province, Hangzhou 311300, China
3. China Key Laboratory of State Forestry and Grassland Administration on Forestry Sensing Technology and Intelligent Equipment, Hangzhou 311300, China
4. College of Optical, Mechanical and Electrical Engineering, Zhejiang A&F University, Lin′an, Hangzhou 311300, China