Vision and the continuity of natural structure in space and scale

Professor Anthony Hayes
Ph.D., The University of Western Australia
Department of Psychology,
The University of Hong Kong

Abstract

In recent years there has been renewed interest in coding by the visual system of the continuities that occur in natural images - a key area of interest of the early 20th Century Gestalt school of psychology. Researchers in anatomy, neurophysiology, computer science, and visual psychophysics, have combined their approaches to develop models of how continuities, such as natural contours, and continuities in depth, colour, shading, are perceived. Most models are based on work that demonstrates that neurons in visual cortex make use of long-range lateral connections that allow integration (and differentiation) of information from far beyond the classical receptive field. I shall present psychophysical results on contour perception, and I shall show how these results converge with recent anatomical and physiological findings. I shall then show how continuity in scale (resolution) in natural images can be considered as analogous to continuity in space, and is perhaps as important to vision as is continuity in space. I shall make the claim that partitioning spatial structure in scale is a fundamental property of visual processing, and that it gives rise to an algorithm that allows neurones with relatively low dynamic range to finely code a wide range of image-intensity variation.