Histogram-Equalization based Adaptive Image Sensor for real-time Vision

This paper presents an adaptive random access image sensor by using in situ histogram equalization. With this histogram equalization based adaptation, this retina can adapt automatically to different lighting conditions without any opto-mechanical adjustment. Besides its analogue output remains in a constant dynamic range and this improves the post image coding and processing efficiency. A 64×64-pixel prototype chip has been designed and fabricated in a classic 1um Single-Poly Double-Metal CMOS technology. This prototype chip works correctly and demonstrated all the expected adaptive behavior.