Abstract

The perspective image of an obliquely inclined textured surface exhibits shape and density distortions of texture elements. These distortions also systematically shift the projection of the spatial frequencies of which the texture is comprised. Using a set of filters with suitable spatial frequency and orientation resolution, the inclination angle of many textured surfaces may be estimated from these frequency shifts. An algorithm has been developed which uses the amplitude distributions of 2-D Gabor filters to perform this calculation on planar surfaces. The algorithm may be viewed as operating in parallel on a number of patches of the image and consolidating a global inclination value of lateral propagation of local inclination estimates between regions.

© 1989 Optical Society of America