A Wheat Spike Detection Method in UAV Images Based on Improved YOLOv5

Deep-learning-based object detection algorithms have significantly improved the performance of wheat spike detection. However, UAV images crowned with small-sized, highly dense, and overlapping spikes cause the accuracy to decrease for detection. This paper proposes an improved YOLOv5 (You Look Only...

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Main Authors: Jianqing Zhao, Xiaohu Zhang, Jiawei Yan, Xiaolei Qiu, Xia Yao, Yongchao Tian, Yan Zhu, Weixing Cao
Format: Article
Language:English
Published: MDPI AG 2021-08-01
Series:Remote Sensing
Subjects:
Online Access:https://www.mdpi.com/2072-4292/13/16/3095
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author Jianqing Zhao
Xiaohu Zhang
Jiawei Yan
Xiaolei Qiu
Xia Yao
Yongchao Tian
Yan Zhu
Weixing Cao
author_facet Jianqing Zhao
Xiaohu Zhang
Jiawei Yan
Xiaolei Qiu
Xia Yao
Yongchao Tian
Yan Zhu
Weixing Cao
author_sort Jianqing Zhao
collection DOAJ
description Deep-learning-based object detection algorithms have significantly improved the performance of wheat spike detection. However, UAV images crowned with small-sized, highly dense, and overlapping spikes cause the accuracy to decrease for detection. This paper proposes an improved YOLOv5 (You Look Only Once)-based method to detect wheat spikes accurately in UAV images and solve spike error detection and miss detection caused by occlusion conditions. The proposed method introduces data cleaning and data augmentation to improve the generalization ability of the detection network. The network is rebuilt by adding a microscale detection layer, setting prior anchor boxes, and adapting the confidence loss function of the detection layer based on the IoU (Intersection over Union). These refinements improve the feature extraction for small-sized wheat spikes and lead to better detection accuracy. With the confidence weights, the detection boxes in multiresolution images are fused to increase the accuracy under occlusion conditions. The result shows that the proposed method is better than the existing object detection algorithms, such as Faster RCNN, Single Shot MultiBox Detector (SSD), RetinaNet, and standard YOLOv5. The average accuracy (AP) of wheat spike detection in UAV images is 94.1%, which is 10.8% higher than the standard YOLOv5. Thus, the proposed method is a practical way to handle the spike detection in complex field scenarios and provide technical references for field-level wheat phenotype monitoring.
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spelling doaj.art-f1c4d53314d44848a14c2419ba6fa4572023-11-22T09:31:46ZengMDPI AGRemote Sensing2072-42922021-08-011316309510.3390/rs13163095A Wheat Spike Detection Method in UAV Images Based on Improved YOLOv5Jianqing Zhao0Xiaohu Zhang1Jiawei Yan2Xiaolei Qiu3Xia Yao4Yongchao Tian5Yan Zhu6Weixing Cao7National Engineering and Technology Center for Information Agriculture, Nanjing Agricultural University, Nanjing 210095, ChinaNational Engineering and Technology Center for Information Agriculture, Nanjing Agricultural University, Nanjing 210095, ChinaKey Laboratory for Crop System Analysis and Decision Making, Ministry of Agriculture and Rural Affairs, Nanjing 210095, ChinaNational Engineering and Technology Center for Information Agriculture, Nanjing Agricultural University, Nanjing 210095, ChinaNational Engineering and Technology Center for Information Agriculture, Nanjing Agricultural University, Nanjing 210095, ChinaNational Engineering and Technology Center for Information Agriculture, Nanjing Agricultural University, Nanjing 210095, ChinaNational Engineering and Technology Center for Information Agriculture, Nanjing Agricultural University, Nanjing 210095, ChinaNational Engineering and Technology Center for Information Agriculture, Nanjing Agricultural University, Nanjing 210095, ChinaDeep-learning-based object detection algorithms have significantly improved the performance of wheat spike detection. However, UAV images crowned with small-sized, highly dense, and overlapping spikes cause the accuracy to decrease for detection. This paper proposes an improved YOLOv5 (You Look Only Once)-based method to detect wheat spikes accurately in UAV images and solve spike error detection and miss detection caused by occlusion conditions. The proposed method introduces data cleaning and data augmentation to improve the generalization ability of the detection network. The network is rebuilt by adding a microscale detection layer, setting prior anchor boxes, and adapting the confidence loss function of the detection layer based on the IoU (Intersection over Union). These refinements improve the feature extraction for small-sized wheat spikes and lead to better detection accuracy. With the confidence weights, the detection boxes in multiresolution images are fused to increase the accuracy under occlusion conditions. The result shows that the proposed method is better than the existing object detection algorithms, such as Faster RCNN, Single Shot MultiBox Detector (SSD), RetinaNet, and standard YOLOv5. The average accuracy (AP) of wheat spike detection in UAV images is 94.1%, which is 10.8% higher than the standard YOLOv5. Thus, the proposed method is a practical way to handle the spike detection in complex field scenarios and provide technical references for field-level wheat phenotype monitoring.https://www.mdpi.com/2072-4292/13/16/3095wheat spike detectionunmanned aerial vehicledeep learningYOLOv5
spellingShingle Jianqing Zhao
Xiaohu Zhang
Jiawei Yan
Xiaolei Qiu
Xia Yao
Yongchao Tian
Yan Zhu
Weixing Cao
A Wheat Spike Detection Method in UAV Images Based on Improved YOLOv5
Remote Sensing
wheat spike detection
unmanned aerial vehicle
deep learning
YOLOv5
title A Wheat Spike Detection Method in UAV Images Based on Improved YOLOv5
title_full A Wheat Spike Detection Method in UAV Images Based on Improved YOLOv5
title_fullStr A Wheat Spike Detection Method in UAV Images Based on Improved YOLOv5
title_full_unstemmed A Wheat Spike Detection Method in UAV Images Based on Improved YOLOv5
title_short A Wheat Spike Detection Method in UAV Images Based on Improved YOLOv5
title_sort wheat spike detection method in uav images based on improved yolov5
topic wheat spike detection
unmanned aerial vehicle
deep learning
YOLOv5
url https://www.mdpi.com/2072-4292/13/16/3095
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