Smart image sensor for wide dynamic range by variable integration time
We propose a computational image sensor in which each pixel controls its integration time. The integration time of each pixel is selected from among several lengths of integration time and the integration time is shortened if the pixel is bright. Although the integration time of each pixel varies, the pixel intensity is adjusted on the sensor in real time. The dynamic range of the pixel value output from the proposed sensor is increased considerably. A prototype of 64/spl times/48 pixels has been fabricated. The proposed sensor has simple functions for detection of saturation to control the integration time and nonlinear image reconstruction. By using experiments, it has been verified that the sensor can achieve a wide dynamic range by adapting to light.