I. Introduction
Airborne/mobile laser scanner or light detection and ranging (LiDAR) sensor data have emerged in recent years as a leading source for automated extraction of various objects (e.g., buildings, trees, vehicles, terrain, etc.), particularly due to the direct measurements of surface topography both accurately and densely [1], [2]. To date, a variety of methods for tree detection and extraction have been proposed. For color infrared images, different tools have been developed. Some of them use pixel-based methods and give the delineation of the tree crowns, such as the valley following algorithms [3]. Other tools use an object-based method, by modeling a synthetic tree crown template to find the tree top positions [4], [5].