Offset correction of the output of a charge coupled device

1. Field of the Invention An offset is used to correct the output of a charge coupled device (CCD). The correction to the offset is determined by an exponential curve which allows for greater correction when error is large, and little correction when the error is small. The exponential curve may be viewed as a sequence of connected linear segments, and the correction to the offset may be determined by the slope of the segment to which the error maps. As the slopes at large errors are steep, the slope is correspondingly high, and the offset converges towards the correct value quickly. Power consumption is optimized by implementing the offset generation circuit using capacitor charge sharing principles.