A signal processor for use with an imaging sensor system that provides enhanced video imagery. The signal processor may be coupled to a FLIR system, for example, which comprises a plurality of detectors that are scanned across an image scene and reference temperature source during separate portions of each scan cycle. The signal processor comprises an input processor coupled to the imaging sensor system which processes analog signals derived from each of the plurality of detectors. The input processor normalizes the analog signals relative to one another during the active portion of the scan cycle based upon stored data derived from a predetermined sensor responsivity calibration procedure. This normalization function equalizes the gains associated with all channels of the sensor system. The input processor also restores the DC levels of each of the sensor channels to respective DC values related to the reference temperature source during the inactive portion of the scan cycle. This function is performed during the calibration procedure and while the system is in operation. The input processor digitizes the signals which are applied to a scan converter. The scan converter stores the digitized signals and converts the stored signals into signals which are compatible with a video monitor employed to view the image. An output processor is coupled to the scan converter that is employed to process signals in a manner which permits software-controlled digitized image enhancement thereof, and which converts the enhanced signals into analog video output signals compatible with the video monitor.