Comparison of two tree apex delineation techniques

Citation
N. Walsworth et D. King, Comparison of two tree apex delineation techniques, AUTOMATED INTERPRETATION OF HIGH SPATIAL RESOLUTION DIGITAL IMAGERY FOR FORESTRY, INTERNATIONAL FORUM, 1999, pp. 93-104
Citations number
30
Language
INGLESE
art.tipo
Article
Categorie Soggetti
Current Book Contents
Year of publication
1999
Pages
93 - 104
Database
ISI
SICI code
Abstract
High-pass filter and double aspect techniques were utilized to identify asp en tree apexes upon black and white archival aerial photography. In order t o individually assess techniques, synthetic images were created incorporati ng differing image and stand characteristics. Synthetic variables included differing density, crown size, and image noise variations, The algorithms i solated apexes through detection of local gray-scale maxima corresponding t o the illuminated tree tops. Intermediate results showed techniques were ac ceptable for dense regularly spaced tree stands of similar height and unifo rm illumination. At higher image resolutions, crowns commonly displayed mul tiple apexes which necessitated the amalgamation of peaks, A cumulative pix el traversal (cost surface) function was adopted as a technique for delinea ting illuminated crown perimeters and for merging apexes upon single crowns . These algorithms were used for temporal modeling of forest structural cha nges associated with an acid mine site.