基于运动恢复结构的无规则植物叶片面积三维测量方法

3D Measurement Method for Area of Irregular Plant Leaf Based on Structure from Motion

接触式测量植物叶片面积的方法会对叶片造成一定程度的伤害,为此本文提出一种仅利用智能手机的非接触式多类别无规则叶片面积三维测量方法。首先,采用运动恢复结构方法获取植株的三维重建点云,在HSV颜色特征空间去除叶片三维噪点;然后,利用模糊C均值聚类算法分割单个叶片,重建叶片表面三角网格;最后,通过网格法计算叶片面积。对5种不同类别、不同形状的植物叶片进行了测量实验,结果表明,在叶片重叠率和复杂性角度上,面积测量的平均相对误差分别为6.25%和4.81%。本文方法测量稳定、精度高,能够满足多类别无规则植物叶片面积测量的需求。

In order to solve the shortcomings that the existing methods of measuring the area of plant leaves,for example,the traditional direct contact measurement can cause damage to the plant,and the laser scanner or structured light to reconstruct the 3 D model is expensive and complicated. A nondestructive and multi-category measurement method of irregular leaf area was proposed. Firstly,smart phone was used to get images of plants,based on these images,the three-dimensional point cloud of plants was reconstructed by using structure from motion,and the noise of the leaf point cloud was removed by using threshold segmentation algorithm with HSV color space as features. Secondly,the threedimensional point cloud was classified by using the fuzzy C-means clustering algorithm to segment the single leaf point cloud,and then,the surface mesh model of the single leaf was reconstructed by using the Delaunay triangular meshing algorithm. Finally,the leaf area was obtained by calculating the mesh area. To prove the proposed method,five different types of plant leaves with different shapes were measured,and it was compared with the real leaf area. The average error of the calculation result of the proposed method was 6. 25% in terms of leaf overlap data,and from the perspective of the complexity of the blade shape,the average error was 4. 81%. In addition,the samples had been added that actually overlap each other between the leaves for experiments,which increased the reliability of the experiment.The results showed that the method was stable and had high precision,meeting the needs of measuring the leaf area of irregular plants in multiple categories.