Analog VLSI Cellular Implementation of the Boundary Contour System

We present an analog VLSI cellular architecture implementing a simplified version of the Boundary Contour System (BCS) for real-time image processing. Inspired by neuromorphic models across several layers of visual cortex, the design integrates in each pixel the functions of simple cells, complex cells, hyper-complex cells, and bipole cells, in three orientations interconnected on a hexagonal grid. Analog current-mode CMOS circuits are used throughout to perform edge detection, local inhibition, directionally selective long-range diffusive kernels, and renormalizing global gain control. Experimental results from a fabricated pixel prototype in 1.2 m CMOS technology demonstrate the robustness of the architecture in selecting image contours in a cluttered and noisy background.