Interactive Digital Image Processing for Terrain Data Extraction.
Interim Rept. 18 Sep 79-17 Sep 80,
GENERAL ELECTRIC CO LANHAM MD SPACE DIV
Pagination or Media Count:
This study was performed to investigate man-machine interactive digital image processing techniques applied to the extraction of terrain analysis data from aerial imagery. The study focuses primarily on the extraction of vegetation data elements from digitized panchromatic photography, with a small amount of attention given to thermal infrared and side-looking radar imagery. Of thirteen vegetation data elements listed in the USAETL Terrain Analysis Procedural Guide for Vegetation, eight are addressed in varying degrees of depth in the study. Interactive digital techniques are developed for vegetationland cover boundary extraction, and for the extraction of several forest related data elements such as percent canopy closure, number of stems per hectare, tree crown diameter, number of trees per hectare in each stem diameter class, and others. The extraction techniques are developed using an existing general-purpose, interactive digital image analysis system--the General Electric DIAL Digital Image Analysis Laboratory. Results are compared in two cases to those achieved via existing manual analysis procedures. While the interactive digital extraction techniques exhibit a promising potential, some technical problems remain. Further development, testing and evaluation are warranted using greater variety of test imagery, including radar and thermal imagery.
- Cartography and Aerial Photography