基于热红外与可见光图像融合的生菜水分胁迫指数模型研究  

Study on Water Stress Index Model of Lettuce Based on Fusion of Thermal Infrared and Visible Light Images

作　　者：何婷婷 黄媛[3] 高海荣 张钟莉莉 郭瑞[1] 杨英茹[3] HE Ting-ting;HUANG Yuan;GAO Hai-rong;ZHANGZHONG Li-li;GUO Rui;YANG Ying-ru(Intelligent Euipment Technology Research Center,Beijing Academy of Agriculture and Forestry Sciences,Beijing 100097,China;Shanxi Agricultural University,Taigu 030801,Shanxi Province,China;Shijiazhuang Academy of Agriculture and Forestry Sciences,Shijiazhuang 050041,China;Information Equipment Technology Research Center,Beijing Academy of Agriculture and Forestry Sciences,Beijing 100097,China)

机构地区：[1]北京市农林科学院智能装备技术研究中心,北京100097 [2]山西农业大学,山西太谷030801 [3]石家庄市农林科学研究院,石家庄050041 [4]北京市农林科学院信息技术研究中心,北京100097

出　　处：《节水灌溉》2023年第3期116-122,共7页Water Saving Irrigation

基　　金：河北省重点研发计划项目(22327401D);北京市乡村振兴科技项目(20220818)。

摘　　要：为了准确提取作物冠层温度,监测作物水分亏缺状态,以不同水分处理的生菜为研究对象,分别利用手持式热像仪和佳能相机获取生菜的热红外和可见光图像,计算生菜冠层可见光图像与热红外图像的仿射变换参数,并进行配准融合,以获取生菜冠层区域的热红外图像,而后计算不同处理下的基于冠层温度的水分胁迫指数(Crop Water Stress Index, CWSI)与日蒸散量(Evapotranspiration,ET),分析不同灌溉处理下CWSI同ET的相关关系来监测生菜水分亏缺程度。结果表明,基于仿射变换的热红外目标提取方法可以实现生菜冠层的准确提取,剔除背景后生菜冠层的平均温度值由20.25℃下降至19.25℃。不同水分处理下的生菜热红外冠层的CWSI值展示出明显的差异,且CWSI与ET呈显著负相关,当CWSI越大,ET越小,表明CWSI可以应用在生菜水分胁迫状态监测,能够很好的反应土壤水分含量变化状况。In order to accurately extract the temperature of the crop canopy and monitor the state of crop water deficit, this study took lettuce with different moisture treatments as the research object, used a handheld thermal imager and a Canon camera to obtain the thermal infrared and visible light images of the lettuce, respectively. Calculating the affine transformation parameters of the visible light and the thermal infrared image of lettuce crown, and the registration and fusion of the visible and thermal infrared images were performed to obtain the thermal infrared image of the lettuce canopy area. Then the crop water stress index(CWSI) and daily evapotranspiration(ET) based on canopy temperature under different treatments were calculated, and the correlation between CWSI and ET was analyzed to monitor the degree of water deficit in lettuce. The results showed that the thermal infrared target extraction method based on affine transformation could achieve the accurate extraction of lettuce canopy, the average temperature of the lettuce canopy decreased from 20.25 ℃ to 19.25 ℃ after removing the background. The CWSI values of lettuce thermal infrared canopy under different water treatments showed obvious differences, and CWSI was significantly negatively correlated with ET. The larger the CWSI, the smaller the ET, indicating that CWSI can be applied to the monitoring of lettuce water stress, which can well reflect the change of soil water content.

关 键 词：生菜 热红外图像 可见光图像 仿射变换 背景剔除 不同水分处理 作物水分胁迫指数CWSI 

分 类 号：S152.75[农业科学—土壤学]