A 33 $\mu$W 64$\,\times\,$64 Pixel Vision Sensor Embedding Robust Dynamic Background Subtraction for Event Detection and Scene Interpretation

Abstract

A 64 × 64-pixel ultra-low power vision sensor is presented, performing pixel-level dynamic background subtraction as the low-level processing layer of an algorithm for scene interpretation. The pixel embeds two digitally-programmable Switched-Capacitors Low-Pass Filters (SC-LPF) and two clocked comparators, aimed at detecting any anomalous behavior of the current photo-generated signal with respect to its past history. The 45 T, 26 μm square pixel has a fill-factor of 12%. The vision sensor has been fabricated in a 0.35 μm 2P3M CMOS process, powered with 3.3 V, and consumes 33 μ W at 13 fps, which corresponds to 620 pW/frame.pixel.