Accession Number : ADP001219

Title :   The Topographic Primal Sketch and Its Application to Passive Navigation,

Corporate Author : LOCKHEED MISSILES AND SPACE CO INC PALO ALTO CA PALO ALTO RESEARCH LAB

Personal Author(s) : Laffey,Thomas J. ; Haralick,Robert M. ; Watson,Layne T.

Report Date : JUN 1983

Pagination or Media Count : 14

Abstract : A complete mathematical treatment is given for describing the topographic primal sketch of the underlying grey tone intensity surface of a digital image. Each picture element is independently classified and assigned a unique descriptive label, invariant under monotonically increasing gray tone transformation from the set (peak, pit, ridge, ravine, saddle, flat, and hillside), with hillside having subcategories (inflection point, slope, convex hill, concave hill, and saddle hill). The topographic classification is based on the first and second directional derivatives of the estimated image intensity surface. A local, facet model, two-dimensional, cubic polynomial fit is done to estimate the image intensity surface. Zero-crossings of the first directional derivative are identified as locations of interest in the image. Results of the technique applied to digital terrain data and aerial photographs used in the Passive Image Navigation study are presented. (Author)

Descriptors :   *Image processing, *Topography, *Mathematics, *Terrain, Aerial photography, Digital systems, Eigenvalues, Intensity, Surfaces, Gray(Color), Transformations, Passive systems, Navigation, Algorithms, Estimates, Classification, Ridges, Pictures

Distribution Statement : APPROVED FOR PUBLIC RELEASE