A Pixel-Parallel Self-Similitude Processing for Multiple-Resolution Edge-Filtering Analog Image Sensors

Abstract

A pixel-parallel <i xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">self-similitude</i> computation architecture has been developed for multiple-resolution directional edge filtering based on focal-plane image processing. The <i xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">self-similitude</i> organization has enabled pixel-by-pixel multiple-resolution image filtering with minimal complexity in interconnects. As a result, it has become possible to accomplish any (1/2) <i xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">n</i> -resolution directional edge filtering in ( <i xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">n</i> +2) steps. An analog edge-filtering chip implemented using a switched floating-gate MOS (neuMOS) technology that is capable of performing four-directional edge filtering at full, half, and quarter resolutions was designed and fabricated in a 0.35-mum 3-metal CMOS technology. The concept has been experimentally verified using the fabricated chip, and the four-directional edge filtering at full, half, and quarter resolutions was demonstrated by measurement.