Method of processing image signal

Claim 1

A method of converting arbitrary color signals in a first color space into color signals in a second color space, comprising: reading a color chart having a plurality of color patches representing typical colors with different chromas, lightnesses, and hues with a device which is to output color signals in the first color space; determining first-order and second order terms of the read color signals in the first color space as a group of first explanatory variables; subjecting the group of first explanatory variables to a principal component analysis for conversion into a group of second explanatory variables which cross each other; using colorimetric values of the color patches of the color chart as a group of criterion variables, and subjecting the group of criterion variables and the group of second explanatory variables to a multiple regression analysis to determine a matrix of partial regression coefficients; and subjecting arbitrary color signals in the first color space to the matrix of partial regression coefficients for conversion into color signals in the second color space.

Claim 2

A method of converting arbitrary color signals in a first color space into color signals in a second color space, comprising: reading a color chart having a plurality of color patches representing typical colors with different chromas, lightnesses, and hues with a device which is to output color signals in the first color space; determining first-order and second order terms of the read color signals in the first color space as a group of first explanatory variables; subjecting the group of first explanatory variables to a principal component analysis for conversion into a group of second explanatory variables which cross each other; using colorimetric values of the color patches of the color chart as a group of criterion variables, and subjecting the group of criterion variables and the group of second explanatory variables to a multiple regression analysis to determine a matrix of partial regression coefficients; and subjecting arbitrary color signals in the first color space to the matrix of partial regression coefficients for conversion into color signals in the second color space.

Claim 12

A method of processing an image signal, comprising: converting device-dependent image signals produced from a non-reversal film subject into colorimetric signals of an original; converting said colorimetric signals into R, G, B signals in a RGB color system and thereafter logarithmically converting ratios of said R, G, B signals to a basic stimulus into colorimetric equivalent-neutral-density signals; generating rough data of said colorimetric equivalent-neutral-density signals; setting up automatically a gradation conversion curve based on said rough data; converting gradations of said colorimetric equivalent-neutral-density signals based on said gradation conversion curve; inversely logarithmically converting the colorimetric equivalent-neutral-density signals whose gradations have been converted into R, G, B signals; and converting the R, G, B signals into colorimetric signals; said RGB color system comprising a range including reference color stimuli and containing a color reproduction range of a reversal film, or a range including reference color stimuli and containing a color reproduction range of said non-reversal film subject.

Claim 13

A method of processing an image signal, comprising: converting device-dependent image signals produced from a non-reversal film subject into colorimetric signals of an original; converting said colorimetric signals into R, G, B signals in a RGB color system and thereafter logarithmically converting ratios of said R, G, B signals to a basic stimulus into colorimetric equivalent-neutral-density signals; generating rough data of said colorimetric equivalent-neutral-density signals; setting up automatically a gradation conversion curve based on said rough data; converting gradations of said colorimetric equivalent-neutral-density signals based on said gradation conversion curve; inversely logarithmically converting the colorimetric equivalent-neutral-density signals whose gradations have been converted into R, G, B signals; and converting the R, G, B signals into colorimetric signals; said RGB color system comprising a range including reference color stimuli and containing a color reproduction range of a reversal film, or a range including reference color stimuli and containing a color reproduction range of said non-reversal film subject.

Claim 14

A method of processing an image signal, comprising: converting device-dependent image signals produced from an original scene into a plurality of colorimetric signals of said original scene; converting said colorimetric signals into colorimetric equivalent-neutral-density signals; generating rough data of said colorimetric equivalent-neutral-density signals; setting up automatically a gradation conversion curve based on said rough data; converting gradations of said colorimetric equivalent-neutral-density signals based on said gradation conversion curve; converting the colorimetric equivalent-neutral-density signals whose gradations have been converted into a plurality of colorimetric signals; and converting said converted colorimetric signals into c, m, y, k signals whose colors are colorimetrically saved.

Claim 15

A method of processing an image signal, comprising: converting device-dependent image signals produced from an original scene into a plurality of colorimetric signals of said original scene; converting said colorimetric signals into colorimetric equivalent-neutral-density signals; generating rough data of said colorimetric equivalent-neutral-density signals; setting up automatically a gradation conversion curve based on said rough data; converting gradations of said colorimetric equivalent-neutral-density signals based on said gradation conversion curve; converting the colorimetric equivalent-neutral-density signals whose gradations have been converted into a plurality of colorimetric signals; and converting said converted colorimetric signals into c, m, y, k signals whose colors are colorimetrically saved.

Claim 16

A method of processing an image signal, comprising: converting device-dependent image signals produced from an original scene into a plurality of colorimetric signals of said original scene; changing said colorimetric signals into colorimetric signals under a light source different from a light source under which said device-dependent image signals have been produced; converting said colorimetric signals under the different light source into colorimetric equivalent-neutral-density signals; generating rough data of said colorimetric equivalent-neutral-density signals; setting up automatically a gradation conversion curve based on said rough data; converting gradations of said colorimetric equivalent-neutral-density signals based on said gradation conversion curve; converting the colorimetric equivalent-neutral-density signals whose gradations have been converted into a plurality of colorimetric signals; and converting said converted colorimetric signals into c, m, y, k signals whose colors are colorimetrically saved.

Claim 17

A method of processing an image signal, comprising: converting device-dependent image signals produced from an original scene into a plurality of colorimetric signals of said original scene; changing said colorimetric signals into colorimetric signals under a light source different from a light source under which said device-dependent image signals have been produced; converting said colorimetric signals under the different light source into colorimetric equivalent-neutral-density signals; generating rough data of said colorimetric equivalent-neutral-density signals; setting up automatically a gradation conversion curve based on said rough data; converting gradations of said colorimetric equivalent-neutral-density signals based on said gradation conversion curve; converting the colorimetric equivalent-neutral-density signals whose gradations have been converted into a plurality of colorimetric signals; and converting said converted colorimetric signals into c, m, y, k signals whose colors are colorimetrically saved.

Claim 20

A method of processing an image signal, comprising: converting device-dependent image signals produced from an original scene into colorimetric signals of said original scene; converting said colorimetric signals into colorimetric equivalent-neutral-density signals; generating rough data of said colorimetric equivalent-neutral-density signals; setting up automatically a gradation conversion curve based on said rough data; converting said colorimetric signals into dye density signals on a reversal subject; processing said dye density signals under standard image processing conditions including a gradation conversion process, a color correction process, an under color removal process, and a K-plate generating process for conversion into c, m, y, k signals.

Claim 21

A method of processing an image signal, comprising: converting device-dependent image signals produced from an original scene into colorimetric signals of said original scene; converting said colorimetric signals into colorimetric equivalent-neutral-density signals; generating rough data of said colorimetric equivalent-neutral-density signals; setting up automatically a gradation conversion curve based on said rough data; converting said colorimetric signals into dye density signals on a reversal subject; processing said dye density signals under standard image processing conditions including a gradation conversion process, a color correction process, an under color removal process, and a K-plate generating process for conversion into c, m, y, k signals.

Claim 22

A method of processing an image signal, comprising: converting image signals of a reversal subject read by an image reader into a plurality of colorimetric signals on said reversal; converting said colorimetric signals into colorimetric equivalent-neutral-density signals; generating rough data of said colorimetric equivalent-neutral-density signals; setting up automatically a gradation conversion curve based on said rough data; converting gradations of said colorimetric equivalent neutral density signals based on said gradation conversion curve; inversely logarithmically converting the colorimetric equivalent neutral density signals whose gradations have been converted into dye density signals; and processing said dye density signals under standard image processing conditions of said image reader including a gradation conversion process, a color correction process, an under color removal process, and a K-plate generating process for conversion into c, m, y, k signals.

Claim 23

A method of processing an image signal, comprising: converting image signals of a reversal subject read by an image reader into a plurality of colorimetric signals on said reversal; converting said colorimetric signals into colorimetric equivalent-neutral-density signals; generating rough data of said colorimetric equivalent-neutral-density signals; setting up automatically a gradation conversion curve based on said rough data; converting gradations of said colorimetric equivalent neutral density signals based on said gradation conversion curve; inversely logarithmically converting the colorimetric equivalent neutral density signals whose gradations have been converted into dye density signals; and processing said dye density signals under standard image processing conditions of said image reader including a gradation conversion process, a color correction process, an under color removal process, and a K-plate generating process for conversion into c, m, y, k signals.

Claim 26

A method of converting arbitrary color signals in a first color space into color signals in a second color space, comprising: reading a color chart having a plurality of color patches representing typical colors with different chromas, lightnesses, and hues with a device which is to output color signals in the first color space; determining first order and second order terms of the read color signals in the first color space as a group of first explanatory variables; subjecting the group of first explanatory variables to a principal component analysis for conversion into a group of second explanatory variables, wherein each of said second explanatory variables are not correlated to each other to avoid a multicollineation effect during multiple regression analysis; using colorimetric values of the color patches of the color chart as a group of criterion variables, and subjecting the group of criterion variables and the group of second explanatory variables to a multiple regression analysis to determine a matrix of partial regression coefficients; and subjecting arbitrary color signals in the first color space to the matrix of partial regression coefficients for conversion into color signals in the second color space.

Claim 27

A method of converting arbitrary color signals in a first color space into color signals in a second color space, comprising: reading a color chart having a plurality of color patches representing typical colors with different chromas, lightnesses, and hues with a device which is to output color signals in the first color space; determining first order and second order terms of the read color signals in the first color space as a group of first explanatory variables; subjecting the group of first explanatory variables to a principal component analysis for conversion into a group of second explanatory variables, wherein each of said second explanatory variables are not correlated to each other to avoid a multicollineation effect during multiple regression analysis; using colorimetric values of the color patches of the color chart as a group of criterion variables, and subjecting the group of criterion variables and the group of second explanatory variables to a multiple regression analysis to determine a matrix of partial regression coefficients; and subjecting arbitrary color signals in the first color space to the matrix of partial regression coefficients for conversion into color signals in the second color space.