System and method for color characterization and transformation

Claim 3

The method of claim 1, wherein said step of converting said first color data includes the step of converting said first color data to L*a*b* data.

Claim 4

The method of claim 2, wherein said step of converting said first color data further includes the step of: converting said first color data to said L*a*b* data according to the following equation: L*=116(Y/Y.sub.n).sup.1/3 -16, a*=500 (X/X.sub.n).sup.1/3 -(Y/Y.sub.n).sup.1/3 !, and b*=500 (Y/Y.sub.n).sup.1/3 -(Z/Z.sub.n).sup.1/3 !, wherein X, Y, Z are tristimulus values for said first color data and X n , Y n , Z n are white reference tristimulus values for said color imaging system; and wherein said step of adjusting said white reference further includes the step of: adjusting said white reference tristimulus values X n , Y n , Z n according to intensities of said tristimulus values X, Y, Z, thereby adjusting said white reference vector of said color space.

Claim 5

The method of claim 2, wherein said step of converting said first color data further includes the step of: converting said first color data to said L*a*b* data according to the following equations: L*=116(Y/Y.sub.n).sup.1/3 -16, a*=500 (X/X.sub.n).sup.1/3 -(Y/Y.sub.n).sup.1/3 !, and b*=500 (Y/Y.sub.n).sup.1/3 -(Z/Z.sub.n).sup.1/3 !, wherein X, Y, Z are tristimulus values for said first color data and X n , Y n , Z n are white reference tristimulus values for said color imaging system; and wherein said step of adjusting said white reference further includes the step of: adjusting said white reference tristimulus values X n , Y n , Z n according to the following equations: X.sub.n =X.sub.b (1-SAT(X,Y,Z))+X.sub.n *SAT(X,Y,Z), Y.sub.n =Y.sub.b (1-SAT(X,Y,Z))+Y.sub.n *SAT(X,Y,Z), and Z.sub.n =Z.sub.b (1-SAT(X,Y,Z))+Z.sub.n *SAT(X,Y,Z), wherein: SAT(X,Y,Z)=MAX((X-X n )/X k -X n ),(Y-Y n )/(Y k -Y n ),(Z-Z n )/(Z k -Z n )), wherein X b , Y b , Z b are tristimulus values for an imaging base associated with said color imaging system, and wherein X k , Y k , Z k are tristimulus values of maximum intensity values for XYZ in said color imaging system.

Claim 6

The method of claim 1 wherein the white reference vector is adjusted during the conversion according to intensities of said color data, wherein the intensities of said color data are a function of a color value from an imaging base associated with said color imaging system.

Claim 9

The system of claim 6, wherein said means for converting said first color data includes means for converting said first color data to L*a*b* data.

Claim 10

The system of claim 7, wherein said means for converting said first color data further includes: means for converting said first color data to said L*a*b* data according to the following equation: L*=116(Y/Y.sub.n).sup.1/3 -16, a*=500 (X/X.sub.n).sup.1/3 -(Y/Y.sub.n).sup.1/3 !, and b*=500 (Y/Y.sub.n).sup.1/3 -(Z/Z.sub.n).sup.1/3 !, wherein X, Y, Z are tristimulus values for said first color data and X n , Y n , Z n are white reference tristimulus values for said color imaging system; and wherein said means for adjusting said white reference further includes: means for adjusting said white reference tristimulus values X n , Y n , Z n according to intensities of said tristimulus values X, Y, Z, thereby adjusting said white reference vector of said color space.

Claim 11

The system of claim 7, wherein said means for converting said first color data further includes: means for converting said first color data to said L*a*b* data according to the following equations: L*=116(Y/Y.sub.n).sup.1/3 -16, a*=500 (X/X.sub.n).sup.1/3 -(Y/Y.sub.n).sup.1/3 !, and b*=500 (Y/Y.sub.n).sup.1/3 -(Z/Z.sub.n).sup.1/3 !, wherein X, Y, Z are tristimulus values for said first color data and X n , Y n , Z n are white reference tristimulus values for said color imaging system; and wherein said means for adjusting said white reference further includes: means for adjusting said white reference tristimulus values X n , Y n , Z n according to the following equations: X.sub.n =X.sub.b (1-SAT(X,Y,Z))+X.sub.n *SAT(X,Y,Z), Y.sub.n =Y.sub.b (1-SAT(X,Y,Z))+Y.sub.n *SAT(X,Y,Z), and Z.sub.n =Z.sub.b (1-SAT(X,Y,Z))+Z.sub.n *SAT(X,Y,Z), wherein: ##EQU3## wherein X b , Y b , Z b are tristimulus values for an imaging base associated with said color imaging system, and wherein X k , Y k , Z k are tristimulus values of maximum intensity values for XYZ in said color imaging system.

Claim 12

(Amended) A method for performing a color transformation, the method comprising the steps of: obtaining first color data representing output of a first color imaging system; obtaining second color data representing output of a second color imaging system; converting said first color data to third color data using a color space; converting said second color data to fourth color data using said color space; adjusting a first white reference vector of said color space during the conversion of said first color data according to intensities of said first color data; adjusting a second white reference vector of said color space during the conversion of said second color data according to intensities of said second color data; and mapping said fourth color data to said third color data to generate color transformation data.

Claim 13

(Amended) A method for performing a color transformation, the method comprising the steps of: obtaining first color data representing output of a first color imaging system; obtaining second color data representing output of a second color imaging system; converting said first color data to third color data using a color space; converting said second color data to fourth color data using said color space; adjusting a first white reference vector of said color space during the conversion of said first color data according to intensities of said first color data; adjusting a second white reference vector of said color space during the conversion of said second color data according to intensities of said second color data; and mapping said fourth color data to said third color data to generate color transformation data.

Claim 14

The method of claim 10, wherein said step of converting said first color data includes the step of converting said first color data to L*a*b* data, and said step of converting said second color data includes the step of converting said second color data to L*a*b* data.

Claim 15

The method of claim 11, wherein: said step of converting said first color data further includes the step of: converting said first color data to said L*a*b* data according to the following equation: L*=116(Y.sub.1 /Y.sub.n1).sup.1/3 -16, a*=500 (X.sub.1 /X.sub.n1).sup.1/3 -(Y.sub.1 /Y.sub.n1).sup.1/3 !, and b*=500 (Y.sub.1 /Y.sub.n1).sup.1/3 -(Z.sub.1 /Z.sub.n1).sup.1/3 !, wherein X 1 , Y 1 , Z 1 are tristimulus values for said first color data, and X n1 , Y n1 , Z n1 are white reference tristimulus values for said first color imaging system, and wherein said step of adjusting said first white reference vector includes the step of: adjusting said white reference tristimulus values X n1 , Y n1 , Z n1 according to intensities of said tristimulus values X 1 , Y 1 , Z 1 , thereby adjusting said first white reference vector of said color space, and wherein said step of converting said second color data further includes the step of: converting said second color data to said L*a*b* data according to the following equation: L*=116(Y.sub.2 /Y.sub.n2).sup.1/3 -16, a*=500 (X.sub.2 /X.sub.n2).sup.1/3 -(Y.sub.2 /Y.sub.n2).sup.1/3 !, and b*=500 (Y.sub.2 /Y.sub.n2).sup.1/3 -(Z.sub.2 /Z.sub.n2).sup.1/3 !, wherein X 2 , Y 2 , Z 2 are tristimulus values for said second color data, and X n2 , Y n2 , Z n2 are white reference tristimulus values for said second color imaging system, and wherein said step of adjusting said second white reference vector includes the step of: adjusting said white reference tristimulus values X n2 , Y n2 , Z n2 according to intensities of said tristimulus values X 2 , Y 2 , Z 2 thereby adjusting said second white reference vector of said color space.

Claim 16

The method of claim 11, wherein: said step of converting said first color data further includes the step of: converting said first color data to said L*a*b* data according to the following equation: L*=116(Y.sub.1 /Y.sub.n1).sup.1/3 -16, a*=500 (X.sub.1 /X.sub.n1).sup.1/3 -(Y.sub.1 /Y.sub.n1).sup.1/3 !, and b*=500 (Y.sub.1 /Y.sub.n1).sup.1/3 -(Z.sub.1 /Z.sub.n1).sup.1/3 !, wherein X 1 , Y 1 , Z 1 are tristimulus values for said first color data, and X n1 , Y n1 , Z n1 are white reference tristimulus values for said first color imaging system, and wherein said step of adjusting said first white reference vector includes the step, of: adjusting said white reference tristimulus values X n1 , Y n1 , Z n1 according to the following equations: X.sub.n1 =X.sub.b1 (1-SAT(X.sub.1,Y.sub.1,Z.sub.1))+X.sub.n1 *SAT(X.sub.1,Y.sub.1, Z.sub.1), Y.sub.n1 =Y.sub.b1 (1-SAT(X.sub.1,Y.sub.1,Z.sub.1))+Y.sub.n1 *SAT(X.sub.1, Y.sub.1, Z.sub.1), and Z.sub.n1 =Z.sub.b1 (1-SAT(X.sub.1,Y.sub.1,Z.sub.1))+Z.sub.n1 *SAT(X.sub.1,Y.sub.1,Z.sub.1), wherein: ##EQU4## wherein X b1 , Y b1 , Z b1 are tristimulus values for an imaging base associated with said first color imaging system, and wherein X k1 , Y k1 , Z k1 are tristimulus values of maximum intensity values for XYZ in said first color imaging system, and said step of converting said second color data further includes the step of: converting said second color data to said L*a*b* data according to the following equation: L*=116(Y.sub.2 /Y.sub.n2).sup.1/3 -16, a*=500 (X.sub.2 /X.sub.n2).sup.1/3 -(Y.sub.2 /Y.sub.n2).sup.1/3 !, and b*=500 (Y.sub.2 /Y.sub.n2).sup.1/3 -(Z.sub.2 /Z.sub.n2).sup.1/3!, wherein X 2 , Y 2 , Z 2 are tristimulus values for said second color data, and X n2 , Y n2 , Z n2 are white reference tristimulus values for said second color imaging system, and wherein said step of adjusting said second white reference vector includes the step of: adjusting said white reference tristimulus values X n2 , Y n2 , Z n2 according to the following equations: X.sub.n2 =X.sub.b2 (1-SAT(X.sub.2,Y.sub.2,Z.sub.2))+X.sub.n2 *SAT(X.sub.2,Y.sub.2,Z.sub.2), Y.sub.n2 =Y.sub.b2 (1-SAT(X.sub.2,Y.sub.2,Z.sub.2))+Y.sub.n2 *SAT(X.sub.2,Y.sub.2,Z.sub.2), and Z.sub.n2 =Z.sub.b2 (1-SAT(X.sub.2,Y.sub.2,Z.sub.2))+Z.sub.n2 *SAT(X.sub.2,Y.sub.2,Z.sub.2) wherein ##EQU5## wherein X b2 , Y b2 , Z b2 are tristimulus values for an imaging base associated with said second color imaging system, and wherein X k2 , Y k2 , Z k2 are tristimulus values of maximum intensity values for XYZ in said second color imaging system.

Claim 19

The system of claim 14, wherein said means for converting said first color data includes means for converting said first color data to L*a*b* data, and said means for converting said second color data includes means for converting said second color data to L*a*b* data.

Claim 20

The system of claim 15, wherein: said means for converting said first color data further includes: means for converting said first color data to said L*a*b* data according to the following equation: L*=116(Y.sub.1 /Y.sub.n1).sup.1/3 -16, a*=500 (X.sub.1 /X.sub.n1).sup.1/3 -(Y.sub.1 /Y.sub.n1).sup.1/3 !, and b*=500 (Y.sub.1 /Y.sub.n1).sup.1/3 -(Z.sub.1 /Z.sub.n1).sup.1/3 !, wherein X 1 , Y 1 , Z 1 are tristimulus values for said first color data, and X n1 , Y n1 , Z n1 are white reference tristimulus values for said first color imaging system, and wherein said means for adjusting said first white reference vector further includes: means for adjusting said white reference tristimulus values Y n1 , Y n1 , Z n1 according to intensities of said tristimulus values X 1 , Y 1 , Z 1 , thereby adjusting said first white reference vector of said color space, and wherein said means for converting said second color data further includes: means for converting said second color data to said L*a*b* data according to the following equation: L*=116(Y.sub.2 /Y.sub.n2).sup.1/3 -16, a*=500 (X.sub.2 /X.sub.n2).sup.1/3 -(Y.sub.2 /Y.sub.n2).sup.1/3 !, and b*=500 (Y.sub.2 /Y.sub.n2).sup.1/3 -(Z.sub.2 /Z.sub.n2).sup.1/3 !, wherein X 2 , Y 2 , Z 2 are tristimulus values for said second color data, and X n2 , Y n2 , Z n2 are white reference tristimulus values for said second color imaging system, and wherein said means for adjusting said second white reference vector further includes: means for adjusting said white reference tristimulus values X n2 , Y n2 , Z n2 according to intensities of said tristimulus values X 2 , Y 2 , Z 2 , thereby adjusting said second white reference vector of said color space.

Claim 21

The system of claim 15, wherein: said means for converting said first color data further includes: means for converting said first color data to said L*a*b* data according to the following equation: L*=116(Y.sub.1 /Y.sub.n1).sup.1/3 -16, a*=500 (X.sub.1 /X.sub.n1).sup.1/3 -(Y.sub.1 /Y.sub.n1).sup.1/3 !, and b*=500 (Y.sub.1 /Y.sub.n1).sup.1/3 -(Z.sub.1 /Z.sub.n1).sup.1/3 !, wherein X 1 , Y 1 , Z 1 are tristimulus values for said first color data, and X n1 , Y n1 , Z n1 are white reference tristimulus values for said first color imaging system, and wherein said means for adjusting said first white reference vector further includes: means for adjusting said white reference tristimulus values X n1 , Y n1 , Z n1 according to the following equations: X.sub.n1 =X.sub.b1 (1-SAT(X.sub.1,Y.sub.1,Z.sub.1))+X.sub.n1 *SAT(X.sub.1,Y.sub.1,Z.sub.1), Y.sub.n1 =Y.sub.b1 (1-SAT(X.sub.1,Y.sub.1,Z.sub.1))+Y.sub.n1 *SAT(X.sub.1,Y.sub.1,Z.sub.1), and Z.sub.n1 =Z.sub.b1 (1-SAT(X.sub.1,Y.sub.1,Z.sub.1))+Z.sub.n1 *SAT(X.sub.1,Y.sub.1,Z.sub.1) wherein ##EQU6## wherein X b1 , Y b1 , Z b1 are tristimulus values for an imaging base associated with said first color imaging system, and wherein X k1 , Y k1 , Z k1 are tristimulus values of maximum intensity values for XYZ in said first color imaging system, and said means for converting said second color data further includes: means for converting said second color data to said L*a*b* data according to the following equation: L*=116(Y.sub.2 /Y.sub.n2).sup.1/3 -16, a*=500 (X.sub.2 /X.sub.n2).sup.1/3 -(Y.sub.2 /Y.sub.n2).sup.1/3 !, and b*=500 (Y.sub.2 /Y.sub.n2).sup.1/3 -(Z.sub.2 /Z.sub.n2).sup.1/3 !, wherein X 2 , Y 2 , Z 2 are tristimulus values for said second color data, and X n2 , Y n2 , Z n2 are white reference tristimulus values for said second color imaging system, and wherein said means for adjusting said second white reference vector further includes: means for adjusting said white reference tristimulus values X n2 , Y n2 , Z n2 according to the following equations: X.sub.n2 =X.sub.b2 (1-SAT(X.sub.2,Y.sub.2,Z.sub.2))+X.sub.n2 *SAT(X.sub.2,Y.sub.2,Z.sub.2), Y.sub.n2 =Y.sub.b2 (1-SAT(X.sub.2,Y.sub.2,Z.sub.2))+Y.sub.n2 *SAT(X.sub.2,Y.sub.2,Z.sub.2), and Z.sub.n2 =Z.sub.b2 (1-SAT(X.sub.2,Y.sub.2,Z.sub.2))+Z.sub.n2 *SAT(X.sub.2,Y.sub.2,Z.sub.2), wherein ##EQU7## wherein X b2 , Y b2 , Z b2 are tristimulus values for an imaging base associated with said second color imaging system, and wherein X k2 , Y k2 , Z k2 are tristimulus values of maximum intensity values for XYZ in said second color imaging system.