The present invention discloses a method and
system for extracting the effective
leaf area index (ELAI) based on
point cloud data. First, three-dimensional
point cloud data containing planted areas is acquired. Then, using the color and geometric information of the
point cloud data, the
color index (EXG) of the point
cloud data is calculated, along with a set of height and slope thresholds. The Otsu filter method, combined with an improved slope-based filtering method, is used to filter out exposed ground points, thereby obtaining a
crop point cloud. The
crop point cloud is then projected onto an upper hemisphere with a
radius of 1, then onto a plane and binarized to obtain a hemispherical image. Finally, the hemispherical image is divided into 18 concentric rings at a zenithal perspective, and the
porosity at specific perspectives is calculated to estimate the ELAI. This method filters out remaining exposed ground points, avoiding the problem of using only the Otsu filter method to automatically determine the
color index (EXG) threshold to filter out ground points, which can result in a small number of ground points remaining and thus lead to an overestimation of the ELAI.