基于3-D图像的植物亏水胁迫萎蔫体态辨识方法

摘要

萎蔫现象是植物亏水胁迫环境下表现出的一种生命特征.为了定量辨识植株的萎蔫体态,在应用激光扫描装置快速获取植株3-D图像基础上,定义了4种萎蔫指数,即叶面卷曲统计指数、叶片形心的高斯曲率、基于形心切平面的叶尖投影以及叶片边缘投影求和平均.实验方法将叶片萎蔫程度分为5个等级水平(LS1～LS5),通过逐一检验每种定义的萎蔫指数是否具有单调性得出可应用性结论.实验结果表明距离投影算法满足萎蔫指数的单调要求,尤其是叶片边缘投影求和平均萎蔫指数具有更好的鲁棒性.%To identify the wilted plant morphology, based on the 3-D images obtained from a laser-scanner, four types of wilt-index were defined, including statistical index of wilt-induced leaf ( SIWL) , Gaussian curvature at the physical center of leave, projecting distance from leaf-tip or leaf-edge to a referenced plane being tangent at the physical center of leaf. For the experimental methodology, the wilted-leaf statuses were divided into five levels, which were used for verifying whether each defined index had monotone property from earlier to serious degree of wilt status. The experimental results demonstrated that the indices in terms of the projecting distance method could meet the requirement for this purpose. In particular, the index relating the leaf-edge to the referenced plane could provide more robust results.