Accession Number : ADA189617

Title :   Automated Stereophotogrammetry.

Descriptive Note : Final rept. 18 Sep 85-17 Sep 87,

Corporate Author : VIRGINIA POLYTECHNIC INST AND STATE UNIV BLACKSBURG DEPT OF ELECTRICAL ENGINEE RING

Personal Author(s) : Nadler, Morton

PDF Url : ADA189617

Report Date : 10 Dec 1987

Pagination or Media Count : 24

Abstract : Using a pattern recognition approach, we have developed a fast program for finding characteristic points and calculating disparities in pairs of photographs. The procedure derives oriented edge-vector graphs from the photos, locates singular points (nodes) in the graphs, and then tests a small window about these points for match. In common with other window-matching approaches, the procedure uses a coarse-to-fine analysis, where the averaged blocks in the coarse resolutions are staggered to simulate a hexagonal array. This enables use to take advantage of the unique topological properties of such arrays. Under a slow image processing environment (GIPSY on VAX 11/785) a dense network of matched points was obtained at the rate of 5 pts/s, compared to 15 pts/s at ETL on a CYBER-730. The ETL procedure required interactive priming with a certain number of initial matches. Keywords: Stereophotogrammetry Pattern recognition, Topological method, Hexagonal scan array.

Descriptors :   *AUTOMATION, *PATTERN RECOGNITION, *STEREOPHOTOGRAMMETRY, ARRAYS, DENSITY, GRAPHS, IMAGE PROCESSING, INTERACTIONS, NETWORKS, PHOTOGRAPHS, PRIMERS, RECOGNITION, TOPOLOGY, WINDOWS

Subject Categories : Cartography and Aerial Photography

Distribution Statement : APPROVED FOR PUBLIC RELEASE