PIXEL CORRECTION LOGIC CIRCUIT

Unprocessed video signals from an optical scanner are processed in accordance with a transfer function which adjusts the gain of the unprocessed video to produce processed video which better represents the form of the object scanned. The transfer function is selected from a memory including a plurality of such functions by a signature signal which characterizes the entire scanner system including the optical system, the illumination system and the sensor system. The signature signal is developed from an initial value of signature which is updated by processing with the unprocessed video.