中国农业科学 ›› 2020, Vol. 53 ›› Issue (8): 1545-1555.doi: 10.3864/j.issn.0578-1752.2020.08.005

• 耕作栽培·生理生化·农业信息技术 • 上一篇    下一篇

基于无人机多光谱遥感图像的玉米田间杂草识别

赵静1,2,李志铭1,2,鲁力群2,3,贾鹏1,2,杨焕波1,2,兰玉彬1,2()   

  1. 1 山东理工大学农业工程与食品科学学院,山东淄博255000
    2 山东理工大学国际精准农业航空应用技术研究中心,山东淄博255000
    3 山东理工大学交通与车辆工程学院,山东淄博255000
  • 收稿日期:2019-08-29 接受日期:2019-11-04 出版日期:2020-04-16 发布日期:2020-04-29
  • 通讯作者: 兰玉彬
  • 作者简介:赵静,E-mail: zbceozj@163.com。
  • 基金资助:
    山东省引进顶尖人才“一事一议”专项经费资助项目;中央引导地方科技发展专项资金“精准农业航空技术与装备研发”资助项目

Weed Identification in Maize Field Based on Multi-Spectral Remote Sensing of Unmanned Aerial Vehicle

ZHAO Jing1,2,LI ZhiMing1,2,LU LiQun2,3,JIA Peng1,2,YANG HuanBo1,2,LAN YuBin1,2()   

  1. 1 School of Agricultural Engineering and Food Science, Shandong University of Technology, Zibo 255000, Shandong
    2 International Research Center of Precision Agriculture Aviation Application Technology, Shandong University of Technology, Zibo 255000, Shandong
    3 School of Transportation and Vehicle Engineering, Shandong University of Technology, Zibo 255000, Shandong
  • Received:2019-08-29 Accepted:2019-11-04 Online:2020-04-16 Published:2020-04-29
  • Contact: YuBin LAN

摘要:

【目的】为了精确高效识别玉米田间杂草,减少除草剂施用,提高玉米种植管理精准性。【方法】通过六旋翼无人机搭载多光谱相机获取玉米田块多光谱图像。为分离图像中植被与非植被像元,计算了7种植被指数,采用最大类间方差法提取植被指数图像中非植被区域,制作掩膜文件并对多光谱图像掩膜。通过主成分分析对多光谱图像进行变换,保留信息量最多的前3个主成分波段。将试验区域分为训练区域和验证区域,在训练区域中分别选取了675处玉米和525处杂草样本对监督分类模型进行训练,在验证区域选取了240处玉米样本及160处杂草样本评价模型分类精度。将7种植被指数、3个主成分波段的24个纹理特征及经过滤波的10个反射率,共计41项特征作为样本特征参数。利用支持向量机-特征递归消除算法(support vector machines-feature recursive elimination,SVM-RFE)和Relief算法从41项特征中各筛选14项特征构成特征子集,采用支持向量机、K-最近邻、Cart决策树、随机森林和人工神经网络对特征子集进行监督分类。【结果】支持向量机与随机森林对全部特征及2个特征子集分类效果较好,支持向量机总体精度为89.13%—91.94%,Kappa>0.79,随机森林总体精度为89.27%—90.95%,Kappa>0.79。【结论】SVM-RFE算法对数据降维效果优于Relief算法,支持向量机(SVM)模型对区域冠层尺度下玉米与杂草的分类效果最好。

关键词: 杂草识别, 无人机遥感, 多光谱图像, 特征选择, 监督分类

Abstract:

【Objective】In order to reduce the application rate of herbicides and to make the maize planting management more effective, the accurate identification of weeds in maize fields was investigated based on multi-spectral remote sensing of unmanned aerial vehicles (UAV). 【Method】In this paper, a Red Edge-M multi-spectral camera was mounted in a six-rotor UAV to acquire five single-band images of blue, green, red, red edge, and near-infrared, and the application was taken in Zibo, Shandong province, China to acquire multi-spectral images of a maize field in July 14, 2018. In order to separate the vegetation and non-vegetation pixels in the image, 7 vegetation indices were calculated, the OTSU method was used to obtain the non-vegetation area, and the multi-spectral image was masked. Then multi-spectral image was transformed by principal component analysis, retaining the first three principal component bands with the most information. The experimental region was divided into 3 training areas and 1 verification area. 675 maize and 525 weed samples were selected in the training areas to train the supervised classification model, and 240 maize and 160 weed samples were selected in the verification area to evaluate model classification accuracy. The 7 vegetation indices, 24 texture features of the 3 principal component bands and 10 reflectivity of multi-spectral image bands which were filtered, and a total of 41 features were taken as features of maize and weed. Support vector machines-feature recursive elimination (SVM-RFE) algorithm and Relief algorithm were applied to selecting 14 features from 41 features to constitutes a feature subset separately, and supervised classification for weed detection was performed using support vector machine (SVM), K-nearest neighbor (KNN), Cart decision tree (Cart), random forest (RF) and artificial neural network (ANN) .【Result】SVM and RF performed a better classification with all features and SVM-RFE & Relief feature subsets. The overall accuracy of SVM was 89.13%-91.94%, Kappa>0.79, and overall accuracy of random forest was 89.27%-90.95%, Kappa>0.79.【Conclusion】 SVM-RFE feature selection algorithm was better than the Relief feature algorithm for reducing the original features. SVM model had the highest classification accuracy for identification of weed and maize at regional canopy scales.

Key words: weed identification, UAV remote sensing, multi-spectral image, feature selection, supervised classification