Patent ID: 7729015

Claim:
A method comprising: (a) receiving multiple input patches on an output media which are characterized by print density representing a document processing system's response to different input grayscale values over a potential response space; (b) measuring values associated with the print density of each input grayscale value using a sensor; (c) determining reference Engine Response Curves from the measured print density values and input grayscale values; (d) determining a variance data representative of a difference between each measured print density value and a respective reference Engine Response Curve; (e) transforming the variance data into individual components using a transformation processor, wherein each individual component including a data content and a noise content; (f) based at least on one selected individual component, determining a set of calibration compensating Tone Reproduction Curves; and (g) applying the determined calibration compensating Tone Reproduction Curves to input grayscale values.