A multi-band watershed segmentation method for individual tree crown delineation from high resolution multispectral aerial image

A comprehensive forest resource inventory needs more detailed species information at individual tree level. Although conventional ground-based measurement fails to achieve this target in an efficient way, the emergence of high resolution remote sensing images has made it possible in the past decade. Individual tree crown delineation is one of the most critical steps for tree species classification from remote sensing images. However, it is still challenging to delineate individual tree crowns in deciduous forests because of the continuous canopy. In this study, a multi-band watershed segmentation method is proposed to delineate deciduous tree crowns by constructing a spectral angle space. The proposed algorithm is further examined by a high resolution multispectral aerial image of a deciduous forested area in Haliburton Forest, Ontario, Canada. Results demonstrate that, the proposed multi-band watershed segmentation method outperforms the existing valley-following based ITC map, in terms of visual interpretation and quantitative evaluation.