Patent ID: 7787151

Claim:
A method for setting a color tone of a monochrome image, comprising the steps of: (a) displaying a color tone setting window, using a graphical user interface module, for use in setting a color tone of a monochrome image, the color tone setting window including an ink color circle for specifying color component intensities representing three chromatic primary color inks with a single specified point therein; and (b) determining the color component intensities representing the three chromatic primary color inks as parameters defining the color tone of the monochrome image in accordance with the position of a point specified in the ink color circle using a color tone determination module, wherein the ink color circle is configured to enable the color component intensities representing the three chromatic primary color inks to be visually recognized from the position in the ink color circle, an arbitrary point in the ink color circle is mapped to a corresponding point in an ink color triangle which is a hypothetical equilateral triangle corresponding to the ink color circle, the ink color triangle is an equilateral triangle having a common center with the ink color circle such that the color component intensities representing the three chromatic primary color inks at the corresponding point are determined in accordance with lengths of three lines drawn perpendicularly to three sides of the ink color triangle respectively from the corresponding point, three vertices of the ink color triangle correspond to three chromatic primary colors of cyan, magenta, and yellow, the ink color triangle circumscribes the ink color circle, an arbitrary point in the ink color circle is mapped to a corresponding point in an inscribed circle of the ink color triangle, and the corresponding point in the ink color triangle corresponding to an arbitrary point in the ink color circle is mapped such that the corresponding point is present on a straight line connecting the center of the ink color circle and the arbitrary point.