Object-background discrimination using analog vlsi circuit

Abstract

An analog VLSI circuit having a network of resistive elements and switches is provided for discriminating between an object and the background in a sensor image of a scene. A sensor system captures two-dimensional visual images and identifies edges of objects. The output of the imaging system is mapped onto the switched resistive grid. The presence of object edges causes switches to open at corresponding grid points in the resistive network. The periphery of the grid is connected to a first voltage, while a central point of the grid is connected to a second voltage. An edge map contour of open switches surrounding the central point causes the voltage at every point within the contour to rise to the second voltage, while every grid point outside the contour settles to the first voltage. Thus, the object enclosed by the edge map contour is labeled or tagged with the second voltage and the surrounding background is characterized by the first voltage. The object-background segregation occurs in parallel, independent of the complexity or arc length of the edge map contour. Nonlinear resistive elements, such as saturating resistive circuits, may be used to limit current flow through gaps or breaks in the contour. This prevents full voltage equalization and allows object-background discrimination for discontinuous contours based on a selected voltage threshold.