Abstract: Signal processing circuit for a multi-pixel scanner array is calibrated by establishing gain and offset correction factors from selected scanner signal measurements and known gain/offset settings that provide accurate calibration of the processing circuit on a pixel-by-pixel basis without concern for variations of component and response values within the signal processing circuit itself from nominal values. When used as a film scanner apparatus, measurements of signal responses taken at open gate conditions are compensated by adjusting exposure values for imager operation during film scanning to make the minimum response output of the apparatus for film D.sub.min equal to the minimum derived of open gate condition during the calibration process.