Patent ID: 7817206

Claim:
A method of generating a final exposure setting, comprising: analyzing pixel values in a plurality of dark frame portions that have been captured by a camera imager under different exposure settings, to determine a mathematical relationship between a noise variable and one or more exposure parameter variables; a) selecting one of a plurality of predetermined exposure settings as a current exposure setting for the camera imager; b) generating a captured scene by the camera imager using the current exposure setting; c) selecting according to a coarse granularity search methodology another one of the exposure settings to be the current setting in response to a pixel analysis operation being performed upon the captured scene to determine overexposure or underexposure, wherein the pixel analysis operation determines overexposure or underexposure by (i) computing a noise value using the mathematical relationship at one or more exposure parameters that define the current exposure setting and (ii) comparing the noise value to pixel values in the captured scene; and d) repeating b) and c) at least once; and then e) generating a captured scene by the camera imager using the current exposure setting; f) selecting according to a fine granularity search methodology another one of the exposure settings to be the current setting in response to a pixel analysis operation being performed upon the captured scene to determine overexposure or underexposure; g) repeating e) and f) at least once; and then h) setting the current exposure setting to be the final exposure setting for taking a picture using the camera imager.