Fast tree skeleton extraction using voxel thinning based on tree point cloud

TL;DR

This paper introduces a fast, automatic method for extracting tree skeletons from complex tree point clouds using voxel thinning, classification, and connection algorithms, outperforming existing methods in speed and completeness.

Contribution

The paper presents a novel FTSEM approach combining voxel thinning, leaf filtering, and breakpoint connection to improve speed and accuracy in tree skeleton extraction from point clouds.

Findings

FTSEM is significantly faster than GSA, with runtime from 1.0 to 13.0 seconds.

FTSEM produces more complete and connected tree skeletons.

The method is robust and effective on real-world forest data.

Abstract

Tree skeleton plays an important role in tree structure analysis, forest inventory and ecosystem monitoring. However, it is a challenge to extract a skeleton from a tree point cloud with complex branches. In this paper, an automatic and fast tree skeleton extraction method (FTSEM) based on voxel thinning is proposed. In this method, a wood-leaf classification algorithm was introduced to filter leaf points for the reduction of the leaf interference on tree skeleton generation, tree voxel thinning was adopted to extract raw tree skeleton quickly, and a breakpoint connection algorithm was used to improve the skeleton connectivity and completeness. Experiments were carried out in Haidian Park, Beijing, in which 24 trees were scanned and processed to obtain tree skeletons. The graph search algorithm (GSA) is used to extract tree skeletons based on the same datasets. Compared with GSA method, the FTSEM method obtained more complete tree skeletons. And the time cost of the FTSEM method is evaluated using the runtime and time per million points (TPMP). The runtime of FTSEM is from 1.0 s to 13.0 s, and the runtime of GSA is from 6.4 s to 309.3 s. The average value of TPMP is 1.8 s for FTSEM, and 22.3 s for GSA respectively. The experimental results demonstrate that the proposed method is feasible, robust, and fast with a good potential on tree skeleton extraction.