BLINC: A 640 * 480 CMOS active pixel video camera with adaptive digital processing, extended optical dynamic range, and miniature form factor

摘要

A miniaturized camera utilizing advanced extended dynamic range CMOS APS (active pixel sensor) imager technology and employing real-time histogram equalization has been developed for capturing scenes having high intra-scenic dynamic range. The camera adapts to changes in scene brightness and contrast in two frame periods, and acquires fully processed images in less than 100 milliseconds after power is applied. The BLINC camera contains an automatic exposure time control and is capable of capturing over 8 equivalent f-stops of optical dynamic range. This exposure time control along with programmable extended dynamic range and built-in 12-bit analog to digital converter allows the Sarnoff APS75 CMOS VGA image sensor to accommodate up to 15 f-stops of intra-scenic dynamic range. The APS75 sensor was fabricated with standard CMOS-7 design rules in a 0.5 micron SPTM process. Progressive scan digital video is stored and processed in realtime by an application specific integrated circuit (ASIC) image processor to provide optimal image contrast and exposure. The processed video is then transformed to 10-bits with a proprietary adaptive non-linear mapper before being converted to standard RS-170 analog video. Small size (28.5mm * 28.5 mm * 16 mm), light weight (< 75 g) and low energy consumption (<75 mJ per image) make this camera well suited for UAV, and automotive applications.