Title
A multiscale morphological algorithm for improvements to canopy height models
Abstract
Pixels with distinctively lower elevation values than the surrounding pixels in a canopy height model (CHM) e.g. pixels representing a pit, often lead to the underestimation of tree heights. To rectify the underestimation, this paper presents a novel multiscale CHM improvement algorithm. A multiscale Laplacian operator, a multiscale-based morphological closing operator and a multiscale median filtering operator were applied to a 1-m resolution CHM to detect and replace pit pixels. The root-mean-squared error (RMSE) and the mean absolute error (MAE) before and after the improvement were computed by comparing the CHMs with field measurements. The improvement is evident as the RMSE decreased from 0.699 m to 0.390 m and the MAE decreased from 0.364 m to 0.243 m. Furthermore, individual-tree-extraction algorithms, namely the variable-area-local maxima algorithm and the individual-tree-crown-delineation algorithm, demonstrated that the proposed algorithm increases the accuracy of the estimation of tree heights.
Year
DOI
Venue
2019
10.1016/j.cageo.2019.05.012
Computers & Geosciences
Keywords
Field
DocType
Multiscale,Morphological,Canopy height model,Lidar,Forest
Median filter,Closing (morphology),Computer science,Algorithm,Mean squared error,Operator (computer programming),Pixel,Elevation,Maxima,Laplace operator
Journal
Volume
ISSN
Citations 
130
0098-3004
0
PageRank 
References 
Authors
0.34
0
4
Name
Order
Citations
PageRank
Li Liu150.83
Samsung Lim26812.02
Xuesong Shen352.79
Marta Yebra4144.93