Analyzing Oriented Patterns

Abstract

Oriented patterns, such as those produced by propagation , accretion, or deformation , are conunon in nature and therefore an important class for visual analysis. Our approach to understanding such patterns is to decompose them into two parts: a fiow field , describing the direction of anisotropy, and the residual pattern obtained by describing the image in a coordinate system built from the fiow field. We develop a method for the local estimation of anisotropy and a method for combining the estimates to construct a fiow coordinate system . Several examples of the use of these methods are presented. These included the use of the fiow Coordinates to provide preferred directions for edge detection, detection of anomalies, fitting simple models to the straightened pattern , and detecting singularities in the fiow field.