Extract Tree Crown Boundaries

Function Overview

Crown Outline Extraction extracts the crown contour of each tree from an individual-tree-segmented point cloud according to tree ID, and outputs the result as a vector file. Each polygon feature in the output vector corresponds to one tree and can be used for crown range display, crown width analysis, and subsequent spatial statistics.

Usage

Click TLS Forest > Extract Tree Crown Contour.

Parameter Settings

• Input Data: Select the point cloud data used to extract crown boundaries. Only one LiData file can be selected at a time, and the file must be open in LiDAR360. The input point cloud must have been segmented into individual trees and must contain valid tree ID information.

• Extraction Method: Select the crown boundary extraction method. Convex hull and concave hull are supported.

  • Convex Hull (default): Extracts the convex hull of each tree point cloud on the X-Y plane and ignores Z values. This method is efficient and generates smooth contours, but may include concave areas along the crown edge.

  • Concave Hull: Extracts the concave hull of each tree point cloud on the X-Y plane and ignores Z values. This method preserves more crown boundary details and is suitable for irregular crowns.

  • Maximum Edge Length (m) (default: 2): Used by the concave hull method. A larger value keeps more long edges and makes the contour closer to a convex hull. A smaller value keeps more crown boundary details but reduces processing efficiency. When set to 0, the program uses twice the average point spacing as the maximum edge length.

• Output Path: Set the save path of the crown contour vector file. After processing, all crown contours are written to one vector file, and each crown contour corresponds to an independent polygon feature.

• Default: Restore all parameters to their default values.

Note: The tree IDs in the input point cloud should uniquely identify individual trees. Point clouds without valid tree IDs or individual tree segmentation results cannot generate crown boundaries correctly by tree.