Department of Electrical and Information Engineering, Polytechnic University of Bari, 70125 Bari, Italy.
Sensors (Basel). 2020 Aug 31;20(17):4915. doi: 10.3390/s20174915.
() is a well-known bacterial plant pathogen mainly transmitted by vector insects and is associated with serious diseases affecting a wide variety of plants, both wild and cultivated; it is known that over 350 plant species are prone to attack. In olive trees, it causes olive quick decline syndrome (OQDS), which is currently a serious threat to the survival of hundreds of thousands of olive trees in the south of Italy and in other countries in the European Union. Controls and countermeasures are in place to limit the further spreading of the bacterium, but it is a tough war to fight mainly due to the invasiveness of the actions that can be taken against it. The most effective weapons against the spread of infection in olive trees are the detection of its presence as early as possible and attacks to the development of its vector insects. In this paper, image processing of high-resolution visible and multispectral images acquired by a purposely equipped multirotor unmanned aerial vehicle (UAV) is proposed for fast detection of symptoms in olive trees. Acquired images were processed using a new segmentation algorithm to recognize trees which were subsequently classified using linear discriminant analysis. Preliminary experimental results obtained by flying over olive groves in selected sites in the south of Italy are presented, demonstrating a mean Sørensen-Dice similarity coefficient of about 70% for segmentation, and 98% sensitivity and 93% precision for the classification of affected trees. The high similarity coefficient indicated that the segmentation algorithm was successful at isolating the regions of interest containing trees, while the high sensitivity and precision showed that OQDS can be detected with a low relative number of both false positives and false negatives.
()是一种著名的植物病原菌，主要通过媒介昆虫传播，与影响广泛的多种野生和栽培植物的严重疾病有关；已知有超过 350 种植物易受 感染。在橄榄树中，它会引起橄榄快速衰退综合征（OQDS），这目前是对意大利南部和欧盟其他国家数十万棵橄榄树生存的严重威胁。已经采取了控制和应对措施来限制细菌的进一步传播，但由于可以采取的措施具有侵略性，这是一场艰苦的战斗。防治橄榄树 感染传播最有效的武器是尽早发现其存在，并对其媒介昆虫的发育进行攻击。本文提出了一种利用专门配备的多旋翼无人机（UAV）获取的高分辨率可见和多光谱图像进行图像处理的方法，用于快速检测橄榄树的 症状。使用新的分割算法处理采集的图像，以识别树木，然后使用线性判别分析对其进行分类。本文介绍了在意大利南部选定地点的橄榄园中进行飞行试验获得的初步实验结果，分割的平均 Sørensen-Dice 相似系数约为 70%，受影响树木的分类具有 98%的灵敏度和 93%的精度。高相似系数表明分割算法成功地隔离了包含树木的感兴趣区域，而高灵敏度和精度表明可以用低相对数量的假阳性和假阴性来检测 OQDS。
