THE RETINOMORPHIC APPROACH - PIXEL-PARALLEL ADAPTIVE AMPLIFICATION, FILTERING, AND QUANTIZATION

I describe a vision system that uses neurobiological principles to per form all four major operations found in biological retinae: (1)continu ous sensing for detection, (2) local automatic gain control for amplif ication, (3) spatiotemporal bandpass filtering for preprocessing, and (4) adaptive sampling for quantization. All four operations are perfor med at the pixel level. The system includes a random-access time-divis ion multiplexed communication channel that reads out asynchronous puls e trains from a 64 x 64 pixel array in the imager chip, and transmits them to corresponding locations on a second chip that has a 64 x 64 ar ray of integrators. Both chips are fully functional. I compare and con trast the design principles of the retina with the standard practice i n imager design and analyze the circuits used to amplify, filter, and quantize the visual signal, with emphasis on the performance trade-off s inherent in the circuit topologies used.