A method for compensating for dark current in an image sensor array. In a representative embodiments, the method includes determining a nominal average dark current for the image sensor array, determining location of each pixel in the image sensor array, obtaining a nominal dark current associated with each pixel based on the nominal average dark current and on the location of the pixel, and subtracting the associated nominal dark current from the image signal for each pixel. At least two of the pixels have differing associated nominal dark currents. In other representative embodiments compensation values for dark currents and for differences in channel processing are determined during the same time period.