Abstract: A color conversion method according to the present invention, in which a scanner that outputs a first color value of a device-dependent color space is used, includes the steps of: acquiring the first color value by reading, by the scanner, a printed material which is based on image data composed of C, M, Y, K values; converting the acquired first color value to a second color value using a scanner profile of the scanner; mapping the first color value acquired from the printed material to the K value of the image data of the printed material; determining a correction quantity of the second color value from the mapped first color value and the K value using a scanner profile correcting LUT; and correcting the converted second color value using the determined correction quantity of the second color value, and outputting the second color value after being corrected.

Abstract: A method for verifying a color matching precision includes determining a relationship in a magnitude of a distance X, a distance A, and a distance B, which are respectively distances between an achromatic color point and a new target color gamut point on a boundary of a new target color gamut, a verified target color gamut point on a boundary of a verified target color gamut, and a printer color gamut point on a boundary of a printer color gamut having a same hue. When X is more than A and B is less than A and X, a color matching precision of a new target color gamut point is verified by calculating a color difference between the new target color gamut point and a measured color value of the verified target color gamut point having the same hue as the new target color gamut point.

Abstract: A color conversion method according to the present invention, in which a scanner that outputs a first color value of a device-dependent color space is used, includes the steps of: acquiring the first color value by reading, by the scanner, a printed material which is based on image data composed of C, M, Y, K values; converting the acquired first color value to a second color value using a scanner profile of the scanner; mapping the first color value acquired from the printed material to the K value of the image data of the printed material; determining a correction quantity of the second color value from the mapped first color value and the K value using a scanner profile correcting LUT; and correcting the converted second color value using the determined correction quantity of the second color value, and outputting the second color value after being corrected.

Abstract: A method for verifying a color matching precision includes determining a relationship in a magnitude of a distance X, a distance A, and a distance B, which are respectively distances between an achromatic color point and a new target color gamut point on a boundary of a new target color gamut, a verified target color gamut point on a boundary of a verified target color gamut, and a printer color gamut point on a boundary of a printer color gamut having a same hue. When X is more than A and B is less than A and X, a color matching precision of a new target color gamut point is verified by calculating a color difference between the new target color gamut point and a measured color value of the verified target color gamut point having the same hue as the new target color gamut point.