HISTOGRAM-EQUALIZATION-BASED ADAPTIVE IMAGE SENSOR FOR REAL-TIME VISION

Image sensing and coding are essential to vision machines. This paper presents an adaptive image sensor by using iii situ histogram equaliza tion. With this histogram-equalization-based adaptation, this image se nsor can adapt automatically to different lighting conditions without frame delay and provides a constant image signal excursion range. A CM OS prototype chip of 64 x 64-pixel is presented where each pixel conta ins ten transistors and occupies 50 x 50 mu m(2) in a classic 1-mu m d ouble-metal single-poly process. The experimental results confirm an a daptation over illumination variation of 1:5000.