Detection of Water Content in Lettuce Canopies Based on Hyperspectral Imaging Technology under Outdoor Conditions

To solve the problem of non-destructive crop water content of detection under outdoor conditions, we propose a method to predict lettuce canopy water content by collecting outdoor hyperspectral images of potted lettuce plants and combining spectral analysis techniques and model training methods. Fir...

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Main Authors: Jing Zhao, Hong Li, Chao Chen, Yiyuan Pang, Xiaoqing Zhu
Format: Article
Language:English
Published: MDPI AG 2022-10-01
Series:Agriculture
Subjects:
Online Access:https://www.mdpi.com/2077-0472/12/11/1796
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author Jing Zhao
Hong Li
Chao Chen
Yiyuan Pang
Xiaoqing Zhu
author_facet Jing Zhao
Hong Li
Chao Chen
Yiyuan Pang
Xiaoqing Zhu
author_sort Jing Zhao
collection DOAJ
description To solve the problem of non-destructive crop water content of detection under outdoor conditions, we propose a method to predict lettuce canopy water content by collecting outdoor hyperspectral images of potted lettuce plants and combining spectral analysis techniques and model training methods. Firstly, background noise was removed by correlation segmentation, proposed in this paper, whereby light intensity correction is performed on the segmented lettuce canopy images. We then chose the first derivative combined with mean centering (MC) to preprocess the raw spectral data. Hereafter, feature bands were screened by a combination of Monte Carlo uninformative variable elimination (MCUVE) and competitive adaptive reweighting sampling (CARS) to eliminate redundant information. Finally, a lettuce canopy moisture prediction model was constructed by combining partial least squares (PLS). The correlation coefficient between model predicted and measured values was used as the main model performance evaluation index, and the modeling set correlation coefficient <i>R<sub>c</sub></i> was 82.71%, while the prediction set correlation coefficient <i>R<sub>P</sub></i> was 84.67%. The water content of each lettuce canopy pixel was calculated by the constructed model, and the visualized lettuce water distribution map was generated by pseudo-color image processing, which finally revealed a visualization of the water content of the lettuce canopy leaves under outdoor conditions. This study extends the hyperspectral image prediction possibilities of lettuce canopy water content under outdoor conditions.
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spelling doaj.art-db97f9a6209f43b78051970cec61e24b2023-11-24T03:17:02ZengMDPI AGAgriculture2077-04722022-10-011211179610.3390/agriculture12111796Detection of Water Content in Lettuce Canopies Based on Hyperspectral Imaging Technology under Outdoor ConditionsJing Zhao0Hong Li1Chao Chen2Yiyuan Pang3Xiaoqing Zhu4Research Centre of Fluid Machinery Engineering and Technology, Jiangsu University, Zhenjiang 212013, ChinaResearch Centre of Fluid Machinery Engineering and Technology, Jiangsu University, Zhenjiang 212013, ChinaResearch Centre of Fluid Machinery Engineering and Technology, Jiangsu University, Zhenjiang 212013, ChinaResearch Centre of Fluid Machinery Engineering and Technology, Jiangsu University, Zhenjiang 212013, ChinaResearch Centre of Fluid Machinery Engineering and Technology, Jiangsu University, Zhenjiang 212013, ChinaTo solve the problem of non-destructive crop water content of detection under outdoor conditions, we propose a method to predict lettuce canopy water content by collecting outdoor hyperspectral images of potted lettuce plants and combining spectral analysis techniques and model training methods. Firstly, background noise was removed by correlation segmentation, proposed in this paper, whereby light intensity correction is performed on the segmented lettuce canopy images. We then chose the first derivative combined with mean centering (MC) to preprocess the raw spectral data. Hereafter, feature bands were screened by a combination of Monte Carlo uninformative variable elimination (MCUVE) and competitive adaptive reweighting sampling (CARS) to eliminate redundant information. Finally, a lettuce canopy moisture prediction model was constructed by combining partial least squares (PLS). The correlation coefficient between model predicted and measured values was used as the main model performance evaluation index, and the modeling set correlation coefficient <i>R<sub>c</sub></i> was 82.71%, while the prediction set correlation coefficient <i>R<sub>P</sub></i> was 84.67%. The water content of each lettuce canopy pixel was calculated by the constructed model, and the visualized lettuce water distribution map was generated by pseudo-color image processing, which finally revealed a visualization of the water content of the lettuce canopy leaves under outdoor conditions. This study extends the hyperspectral image prediction possibilities of lettuce canopy water content under outdoor conditions.https://www.mdpi.com/2077-0472/12/11/1796hyperspectral imagingoutdoor conditionspreprocessingfeature selectionwater content predictionlettuce
spellingShingle Jing Zhao
Hong Li
Chao Chen
Yiyuan Pang
Xiaoqing Zhu
Detection of Water Content in Lettuce Canopies Based on Hyperspectral Imaging Technology under Outdoor Conditions
Agriculture
hyperspectral imaging
outdoor conditions
preprocessing
feature selection
water content prediction
lettuce
title Detection of Water Content in Lettuce Canopies Based on Hyperspectral Imaging Technology under Outdoor Conditions
title_full Detection of Water Content in Lettuce Canopies Based on Hyperspectral Imaging Technology under Outdoor Conditions
title_fullStr Detection of Water Content in Lettuce Canopies Based on Hyperspectral Imaging Technology under Outdoor Conditions
title_full_unstemmed Detection of Water Content in Lettuce Canopies Based on Hyperspectral Imaging Technology under Outdoor Conditions
title_short Detection of Water Content in Lettuce Canopies Based on Hyperspectral Imaging Technology under Outdoor Conditions
title_sort detection of water content in lettuce canopies based on hyperspectral imaging technology under outdoor conditions
topic hyperspectral imaging
outdoor conditions
preprocessing
feature selection
water content prediction
lettuce
url https://www.mdpi.com/2077-0472/12/11/1796
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AT hongli detectionofwatercontentinlettucecanopiesbasedonhyperspectralimagingtechnologyunderoutdoorconditions
AT chaochen detectionofwatercontentinlettucecanopiesbasedonhyperspectralimagingtechnologyunderoutdoorconditions
AT yiyuanpang detectionofwatercontentinlettucecanopiesbasedonhyperspectralimagingtechnologyunderoutdoorconditions
AT xiaoqingzhu detectionofwatercontentinlettucecanopiesbasedonhyperspectralimagingtechnologyunderoutdoorconditions