The Analysis of Moving Visual Patterns
J. Anthony Movshon, Edward H. Adelson, Martin S. Gizzi, and William T. Newsome
Study Week on Pattern Recognition Mechanisms (pp. 117-151)
Pontificia Scademia Scientiarvm, V
Eds: Carlos Chagas, Ricardo Gattass, and Charles Gross
Rome: Vatican Press (1985).
There is abundant evidence that the orientation of contours is a feature of considerable importance to the visual
system. Both psychophysical and electrophysiological studies suggest that the retinal image is treated relatively
early in the visual process by orientationally-tuned spatial filters (see Hubel and Wiesel, 1962; Campbell and
Kulikowski, 1966, among many others). Orientational filtering undoubtedly plays a role in the analysis of the
structure of a visual pattern, but the visual system has other tasks, most obviously that of extracting information
about the motion of objects. A simple analysis reveals that separating a two-dimensional image into its
one-dimensional (that is, oriented) components presents problems for a system concerned with extracting object
motion. Here we outline the problem, propose a novel formal solution to it, and consider the applications of this
solution to a variety of perceptual and electrophysiological phenomena.