Image color registration sensor calibration

Color imaging methods and systems are provided where each color separation image is to be registered in a composite manner under a variety of machine conditions. Registration sensors are provided to register the color separations under a variety of machine conditions while accounting for the different types of registration sensors used. A controller calibrates the registration sensors automatically based on set-up data and, using the calibrated sensors, controls the output of the image data for one or more of the color separation images to reduce or eliminate image registration offsets. The registration sensors are calibrated by directly measuring set-up marks during set-up. Each registration sensor outputs a feedback to the controller during set-up to account for phenomenon caused by variation in toner concentration or sensor susceptibility. The registration sensors provide a plurality of set-up sensor feedback values, one for each of at least four colors and one for a bare photoreceptor belt. The controller determines the differences between the set-up sensor feedback value for each of the four colors and the set-up feedback value for the bare photoreceptor belt and uses the determined differences to adjust the operating conditions for each sensor, including the amount of driving current applied to the sensor.