Image Number 5 for United States Patent #5537516.
The present invention is a method for calibrating color reproduction devices such as printers and for stabilizing the print colors generated by a computer controlled color reproduction device. Further, the present invention acts to standardize the print colors produced across a family or series of color reproduction devices. It may be incorporated into a color management system used to produce consistent colors across a variety of reproduction devices. In the first embodiment of the present invention, an object scanning device and an object color reproduction device are used. In the second embodiment, an object densitometer is used as the measuring device to measure densities. In yet another embodiment, an object colorimeter is used as the measuring device to measure CIE values. The present invention enables generation of a set of calibration curves for correcting the color output of the color reproduction device. The calibration curves provide modification functions for each of the individual color print channels of the color reproduction device (e.g., CMYK). The calibration curves are used to alter the rendering of color reproductions, and thereby achieve a desired result. The calibration curves may be downloaded to a color management system to alter the rendering of color images, pages, documents, etc., and thereby achieve a desired result. The calibration curves may also be downloaded directly to the controller of the color reproduction device. The present invention further provides an improved method of measuring ink values using a subject scanner by defocusing or diffusing a target.