Are Contours Dead?
Visual images are two-dimensional. But the regularities of our visual world suggest that a natural image might be adequately represented by the one-dimensional contours projecting from discontinuities in the scene. While this idea has a long history, contour-based algorithms have fallen out of fashion in the computer vision community, and vision scientists of today can be heard to say that they do not ‘believe’ in contours. My goal in this talk is to make you a believer. I will consider three stages of contour processing: detection, organization and recognition. Neural, ecological, psychophysical and computational aspects of contour processing will be considered. Issues include: the role of primary visual cortex, Marr’s completeness conjecture, local, global and top-down influences in perceptual organization, ideal observer theory and technological applications.