Patent ID: 7755677

Claim:
An imager comprising: an image sensing device with controllable gain and exposure control; and an image processing device for providing signals to control the gain and exposure for said image sensing device, said image processing device comprising: a measurement engine for measuring a current luminance value of an image based on data received from said image sensing device; and a logic unit for comparing the current luminance value obtained in the measurement engine with a target luminance value and determining whether or not it is necessary to adjust the brightness of an image, and for calculating a step size for adjusting the brightness if an adjustment is necessary, using a predefined stepping sequence, the logic unit applying the calculated step size to adjust a gain of the image signal and/or an integration time of the image and for calculating an intermediate target luminance value to which the image brightness is to be adjusted, the intermediate target luminance value being between the target luminance value and the current image luminance value, wherein the logic unit iteratively steps through the stepping sequence without physically adjusting the gain and/or integration time at each step and only adjusts the gain and/or integration time for the step at which the intermediate target luminance value is achieved.