Analog model of early visual processing: contour and boundary detection in the retina

摘要

Abstract: Biological and psychophysical data do not rule out a model of retinal processing which allows accurate localization of contours without loss of high frequency image features such as corners and junctions. From an engineering perspective, early contour detection is useful for several applications, among them visually guided camera-image control. Simple, accurate and fast algorithms have been developed for matching based on binary edge maps. These can be incorporated within a control system for self-focusing and image stabilization. The principal features of the analog model are the following: (1) It is robust with respect to noise; (2) It does not lose contrast information or introduce systematic errors; and (3) It allows independent control of thresholding and smoothing. In other words, the interdependence between smoothing and the accuracy of edge localization is removed. The model is implemented by a 2-dimensional network of cells which are connected to their nearest neighbors. We present simulations of the network on a test image and present arguments for its plausibility as a model of retinal processing.!19