Patent ID: 8089668

Claim:
A method of calibrating a scanner, comprising: measuring pixel values, for one or more calibration patches comprising a plurality of pixels, at each of a first predetermined maximum pixel value and a second predetermined maximum pixel value; computing a first average pixel value from scan data acquired at the first predetermined maximum pixel value; identifying a first set of omitted pixels; computing a second average pixel value from scan data acquired at the second predetermined maximum pixel value; identifying a second set of omitted pixels; identifying calibration patches that do not have pixels omitted when measured at the first predetermined maximum pixel value, but that have pixels omitted when measured at the second predetermined maximum pixel value; generating a linear model from the identified calibration patches, wherein the linear model is used to predict patch averages based on the pixels having pixel values below the second predetermined maximum pixel value and a number of omitted pixels from each of a plurality of color separations; employing the linear model to determine an error between the first and second average pixel values; and calibrating the scanner while compensating for the determined error.