Abstract

We present new extensions of steerable filters for image analysis. The architecture permits oriented filters to be applied efficiently over a continuous range of angles. The outputs of several basis filters give an analytic expression for the filter response as a function of angle. We extend our previous analysis to include three-dimensional image filters. The resulting local analysis of the orientation and the phase of volumetric data may be usefully applied to medical imagery and motion sequences. The approach permits considerable computational savings, because a small number of x–y–z separable filters can be used to synthesize an x–y–z nonseparable filter of arbitrary orientation. We also develop techniques for the analysis of multiple orientations at a single point, which are applicable to the analysis of orientation of transparent or occluding surfaces.

© 1990 Optical Society of America