Title
Lychee Fruit Detection Based on Monocular Machine Vision in Orchard Environment.
Abstract
Due to the change of illumination environment and overlapping conditions caused by the neighboring fruits and other background objects, the simple application of the traditional machine vision method limits the detection accuracy of lychee fruits in natural orchard environments. Therefore, this research presented a detection method based on monocular machine vision to detect lychee fruits growing in overlapped conditions. Specifically, a combination of contrast limited adaptive histogram equalization (CLAHE), red/blue chromatic mapping, Otsu thresholding and morphology operations were adopted to segment the foreground regions of the lychees. A stepwise method was proposed for extracting individual lychee fruit from the lychee foreground region. The first step in this process was based on the relative position relation of the Hough circle and an equivalent area circle (equal to the area of the potential lychee foreground region) and was designed to distinguish lychee fruits growing in isolated or overlapped states. Then, a process based on the three-point definite circle theorem was performed to extract individual lychee fruits from the foreground regions of overlapped lychee fruit clusters. Finally, to enhance the robustness of the detection method, a local binary pattern support vector machine (LBP-SVM) was adopted to filter out the false positive detections generated by background chaff interferences. The performance of the presented method was evaluated using 485 images captured in a natural lychee orchard in Conghua (Area), Guangzhou. The detection results showed that the recall rate was 86.66%, the precision rate was greater than 87% and the F-1-score was 87.07%.
Year
DOI
Venue
2019
10.3390/s19194091
SENSORS
Keywords
Field
DocType
overlapped lychee detection,monocular vision,Hough circle,three-point definite circle,LBP-SVM
Monocular vision,Machine vision,Pattern recognition,Local binary patterns,Support vector machine,Adaptive histogram equalization,Electronic engineering,Robustness (computer science),Artificial intelligence,Engineering,Thresholding,Monocular
Journal
Volume
Issue
ISSN
19
19.0
1424-8220
Citations 
PageRank 
References 
0
0.34
0
Authors
9
Name
Order
Citations
PageRank
Qiwei Guo100.68
Yayong Chen200.34
Yu Tang3449.61
Jiajun Zhuang401.01
Yong He54415.57
Chaojun Hou601.01
Xuan Chu700.68
Zhenyu Zhong800.68
Shaoming Luo901.69