Color conversion method using ordered color signal interpolation

Claim 1

A method of establishing a color conversion relationship for converting color signals from a first calorimetric system to a second calorimetric system, comprising the steps of: (a) determining color signals of the first colorimetric system with respect to predetermined color signals of the second colorimetric system; (b) interpolating colors of said second colorimetric system in the order in which changes in color of said first colorimetric system with respect to changes in the colors of said second colorimetric system are progressively greater, thereby determining the color conversion relationship between the colors of said second colorimetric system and said first colorimetric system; and (c) determining a color conversion relationship in a remaining color space by way of interpolation using said color conversion relationship determined in the step (b).

Claim 2

A method of establishing a color conversion relationship for converting color signals from a first calorimetric system to a second calorimetric system, comprising the steps of: (a) determining color signals of the first colorimetric system with respect to predetermined color signals of the second colorimetric system; (b) interpolating colors of said second colorimetric system in the order in which changes in color of said first colorimetric system with respect to changes in the colors of said second colorimetric system are progressively greater, thereby determining the color conversion relationship between the colors of said second colorimetric system and said first colorimetric system; and (c) determining a color conversion relationship in a remaining color space by way of interpolation using said color conversion relationship determined in the step (b).

Claim 13

A method of establishing a color conversion relationship for converting color signals from a first calorimetric system to a second colorimetric system, comprising the steps of: (a) determining color signals of the first calorimetric system with respect to predetermined color signals of the second calorimetric system; (b) interpolating colors of said second calorimetric system in the order in which changes in color of said first colorimetric system with respect to changes in the colors of said second calorimetric system are progressively greater, thereby determining the color conversion relationship between the colors of said second calorimetric system and said first colorimetric system; and (c) determining a color conversion relationship in a remaining color space by way of interpolation using said color conversion relationship determined in the step (b); wherein said step (a) comprises determining a color signal Rd of said first calorimetric system with respect to a predetermined color signal "a" of said second colorimetric system according to: Rd=(1-a-b)·Rw+x·Rs+b·Rg where Rw represents a calorimetrically measured value of an output sheet, Rs a calorimetrically measured value of a color material used, Rg a colorimetrically measured value of a portion of the output sheet having a dot gain obtained from a predetermined relationship, "x" a halftone dot percentage of the color material, and "b" a halftone dot percentage of a portion of the output sheet having a dot gain obtained from the predetermined relationship; wherein said predetermined relationship the for the dot gain is b=√(1-|1-x/50|)·n. 13.

Claim 14

A method of establishing a color conversion relationship for converting color signals from a first calorimetric system to a second colorimetric system, comprising the steps of: (a) determining color signals of the first calorimetric system with respect to predetermined color signals of the second calorimetric system; (b) interpolating colors of said second calorimetric system in the order in which changes in color of said first colorimetric system with respect to changes in the colors of said second calorimetric system are progressively greater, thereby determining the color conversion relationship between the colors of said second calorimetric system and said first colorimetric system; and (c) determining a color conversion relationship in a remaining color space by way of interpolation using said color conversion relationship determined in the step (b); wherein said step (a) comprises determining a color signal Rd of said first calorimetric system with respect to a predetermined color signal "a" of said second colorimetric system according to: Rd=(1-a-b)·Rw+x·Rs+b·Rg where Rw represents a calorimetrically measured value of an output sheet, Rs a calorimetrically measured value of a color material used, Rg a colorimetrically measured value of a portion of the output sheet having a dot gain obtained from a predetermined relationship, "x" a halftone dot percentage of the color material, and "b" a halftone dot percentage of a portion of the output sheet having a dot gain obtained from the predetermined relationship; wherein said predetermined relationship the for the dot gain is b=√(1-|1-x/50|)·n. 13.

Claim 15

A method of establishing a color conversion relationship for converting color signals from a first colorimetric system to a second colorimetric system, comprising the steps of: (a) determining color signals of the first colorimetric system with respect to predetermined color signals of the second colorimetric system; (b) interpolating colors of said second colorimetric system in the order in which changes in color of said first colorimetric system with respect to changes in the colors of said second colorimetric system are progressively greater, thereby determining the color conversion relationship between the colors of said second calorimetric system and said first calorimetric system; and (c) determining a color conversion relationship in a remaining color space by way of interpolation using said color conversion relationship determined in the step (b); wherein said color signals of said first colorimetric system comprise color signals of a common color space, and said color signals of said second colorimetric system comprise color signals of Y, M, C, K; wherein in said step (b), a first component color signal of said second calorimetric system is set to predetermined levels and a second component color signal of said second calorimetric system is viewed against a first component color signal of said first colorimetric system, and the second component color signal of said second colorimetric system is set to said predetermined levels and said first component color signal of said second colorimetric system is viewed against the first component color signal of said first colorimetric system, and said first and second component color signals of said second colorimetric system are interpolated in the order in which changes in color of said first component color signal of said first calorimetric system with respect to changes of said first and second component color signals of said second calorimetric system at said predetermined levels are progressively greater.

Claim 16

A method of establishing a color conversion relationship for converting color signals from a first colorimetric system to a second colorimetric system, comprising the steps of: (a) determining color signals of the first colorimetric system with respect to predetermined color signals of the second colorimetric system; (b) interpolating colors of said second colorimetric system in the order in which changes in color of said first colorimetric system with respect to changes in the colors of said second colorimetric system are progressively greater, thereby determining the color conversion relationship between the colors of said second calorimetric system and said first calorimetric system; and (c) determining a color conversion relationship in a remaining color space by way of interpolation using said color conversion relationship determined in the step (b); wherein said color signals of said first colorimetric system comprise color signals of a common color space, and said color signals of said second colorimetric system comprise color signals of Y, M, C, K; wherein in said step (b), a first component color signal of said second calorimetric system is set to predetermined levels and a second component color signal of said second calorimetric system is viewed against a first component color signal of said first colorimetric system, and the second component color signal of said second colorimetric system is set to said predetermined levels and said first component color signal of said second colorimetric system is viewed against the first component color signal of said first colorimetric system, and said first and second component color signals of said second colorimetric system are interpolated in the order in which changes in color of said first component color signal of said first calorimetric system with respect to changes of said first and second component color signals of said second calorimetric system at said predetermined levels are progressively greater.

Claim 17

A method of establishing a color conversion relationship for converting color signals from a first colorimetric system to a second calorimetric system, comprising the steps of: (a) determining color signals of the first calorimetric system with respect to predetermined color signals of the second colorimetric system; (b) interpolating colors of said second calorimetric system in the order in which changes in color of said first colorimetric system with respect to changes in the colors of said second colorimetric system are progressively greater, thereby determining the color conversion relationship between the colors of said second colorimetric system and said first calorimetric system; and (c) determining a color conversion relationship in a remaining color space by way of interpolation using said color conversion relationship determined in the step (b); wherein said color signals of said first colorimetric system comprise color signals of a common color space, and said color signals of said second colorimetric system comprise color signals of R, G, B; wherein in said step (b), a first component color signal of said second colorimetric system is set to predetermined levels and a second component color signal of said second calorimetric system is viewed against a first component color signal of said first colorimetric system, and the second component color signal of said second calorimetric system is set to said predetermined levels and said first component color signal of said second calorimetric system is viewed against the first component color signal of said first calorimetric system, and said first and second component color signals of said second colorimetric system are interpolated in the order in which changes in color of said first component color signal of said first colorimetric system with respect to changes of said first and second component color signals of said second calorimetric system at said predetermined levels are progressively greater.

Claim 18

A method of establishing a color conversion relationship for converting color signals from a first colorimetric system to a second calorimetric system, comprising the steps of: (a) determining color signals of the first calorimetric system with respect to predetermined color signals of the second colorimetric system; (b) interpolating colors of said second calorimetric system in the order in which changes in color of said first colorimetric system with respect to changes in the colors of said second colorimetric system are progressively greater, thereby determining the color conversion relationship between the colors of said second colorimetric system and said first calorimetric system; and (c) determining a color conversion relationship in a remaining color space by way of interpolation using said color conversion relationship determined in the step (b); wherein said color signals of said first colorimetric system comprise color signals of a common color space, and said color signals of said second colorimetric system comprise color signals of R, G, B; wherein in said step (b), a first component color signal of said second colorimetric system is set to predetermined levels and a second component color signal of said second calorimetric system is viewed against a first component color signal of said first colorimetric system, and the second component color signal of said second calorimetric system is set to said predetermined levels and said first component color signal of said second calorimetric system is viewed against the first component color signal of said first calorimetric system, and said first and second component color signals of said second colorimetric system are interpolated in the order in which changes in color of said first component color signal of said first colorimetric system with respect to changes of said first and second component color signals of said second calorimetric system at said predetermined levels are progressively greater.