Patent ID: 7990425

Claim:
An image pickup apparatus ( 70 ), comprising: an image pickup means (sensor 700 ) for forming a plurality of image signals (S,L) having different exposure conditions, combining means for combining said plurality of image signals to form a combined image signal having an extended dynamic range, further comprising a function module ( 79 ) correcting at least one of the image signals (S,L) in order to achieve a smooth transition between the image signals (S, L) at a transition point (P), wherein the correction function executed in the function module ( 79 ) follows the equation y=x+k x x 2 +k 2 ( x−p ) 2 x > P (6) With: x=input signal, y=output signal (corrected function), k x x 2 =term to compensate for the distortion in the CCD sensor due to the increasing charge, and k 2 (x−p) 2 x>p=term to compensate for the saturation of the output stage.