Gamut description and visualization

Claim 2

1 . A computer-readable medium containing a program for configuring a digital computer to perform a method for comparing a first color gamut able to be produced by a color generating apparatus upon a given medium with a second color gamut, the method comprising the steps of: a) using a first collection of sample color points to create a first hull in the color space, each sample color point in the first collection defining a location in at least a three-dimensional color space and corresponding to a color in the first color gamut, the set of all of the points disposed on the surface of the first hull or within the volume enclosed thereby representing the first color gamut, all of the color points in the first collection of sample color points being disposed on the surface of the hull or within the volume defined thereby; b) using a second collection of sample color points to create a second hull in the color space, each sample color point in the second collection defining a location in at least a three-dimensional color space and corresponding to a color in the second color gamut, the set of all of the points disposed on the surface of the second hull or within the volume enclosed thereby representing the second color gamut, all of the color points in the second collection of sample color points being disposed on the surface of the second hull or within the volume defined thereby; and c) combining the first and second hulls thereby to create a third hull in the color space representing at least one region of overlap or at least one region of exclusion between the first color gamut and the second color gamut.

Claim 3

2 . The computer-readable medium of claim 1 wherein the method further comprises the steps of: d) determining the volume enclosed within one of the first or second hulls; d) determining the volume enclosed within the third hull representing the region of overlap or the region of exclusion; and e) comparing the volumes of the first or second hulls with the volume of the third hull.

Claim 4

3 . The computer-readable medium of claim 1 wherein the combining step is implemented using the Boolean intersection operation to create at least one region of overlap between the first color gamut and the second color gamut and the Boolean difference operation to create at least one region of exclusion between the first color gamut and the second color gamut.

Claim 5

4 . A computer-implemented method for comparing a first color gamut able to be produced by a color generating apparatus upon a given medium with a second color gamut, the method comprising the steps of: a) using a first collection of sample color points to create a first hull in the color space, each sample color point in the first collection defining a location in at least a three-dimensional color space and corresponding to a color in the first color gamut, the set of all of the points disposed on the surface of the first hull or within the volume enclosed thereby representing the first color gamut, all of the color points in the first collection of sample color points being disposed on the surface of the hull or within the volume defined thereby; b) using a second collection of sample color points to create a second hull in the color space, each sample color point in the second collection defining a location in at least a three-dimensional color space and corresponding to a color in the second color gamut, the set of all of the points disposed on the surface of the second hull or within the volume enclosed thereby representing the second color gamut, all of the color points in the second collection of sample color points being disposed on the surface of the second hull or within the volume defined thereby; and c) combining the first and second hulls thereby to create a third hull in the color space representing at least one region of overlap or at least one region of exclusion between the first color gamut and the second color gamut.

Claim 6

4 . A computer-implemented method for comparing a first color gamut able to be produced by a color generating apparatus upon a given medium with a second color gamut, the method comprising the steps of: a) using a first collection of sample color points to create a first hull in the color space, each sample color point in the first collection defining a location in at least a three-dimensional color space and corresponding to a color in the first color gamut, the set of all of the points disposed on the surface of the first hull or within the volume enclosed thereby representing the first color gamut, all of the color points in the first collection of sample color points being disposed on the surface of the hull or within the volume defined thereby; b) using a second collection of sample color points to create a second hull in the color space, each sample color point in the second collection defining a location in at least a three-dimensional color space and corresponding to a color in the second color gamut, the set of all of the points disposed on the surface of the second hull or within the volume enclosed thereby representing the second color gamut, all of the color points in the second collection of sample color points being disposed on the surface of the second hull or within the volume defined thereby; and c) combining the first and second hulls thereby to create a third hull in the color space representing at least one region of overlap or at least one region of exclusion between the first color gamut and the second color gamut.

Claim 7

5 . The computer-implemented method of claim 4 wherein the combining step is implemented using at least one Boolean operation.

Claim 8

6 . The computer-implemented method of claim 5 wherein the combining step is implemented using the Boolean intersection operation to create at least one region of overlap between the first color gamut and the second color gamut.

Claim 9

7 . The computer-implemented method of claim 5 wherein the combining step is implemented using the Boolean difference operation to create at least one region of exclusion between the first color gamut and the second color gamut.

Claim 10

8 . The computer-implemented method of claim 4 further comprising the steps of: d) determining the volume enclosed within one of the first or second hulls; d) determining the volume enclosed within the third hull representing the region of overlap or the region of exclusion; and e) comparing the volumes of the first or second hulls with the volume of the third hull.

Claim 11

9 . The computer-implemented method of claim 4 wherein at least one of the first or second hulls is a convex hull.

Claim 12

10 . The computer-implemented method of claim 4 wherein at least one of the first or second hulls is an alpha hull.

Claim 13

11 . A computer-implemented method for comparing a first color gamut able to be produced by a color generating apparatus upon a given medium with a second color gamut, the method comprising the steps of: a) using a first collection of sample color points to create a plurality of boundary surfaces collectively defining a first hull in the color space, each sample color point in the first collection defining a location in at least a three-dimensional color space and corresponding to a color in the first color gamut, the set of all of the points disposed on the surface of the first hull or within the volume enclosed thereby representing the color gamut able to be produced by the color generating apparatus, all of the color points in the first collection of sample color points being disposed on the surface of the first hull or within the volume defined thereby; b) using a second collection of sample color points to create a plurality of boundary surfaces collectively defining a second hull in the color space, each sample color point in the second collection defining a location in at least a three-dimensional color space and corresponding to a color in the second color gamut, the set of all of the points disposed on the surface of the second hull or within the volume enclosed thereby representing the second color gamut, all of the color points in the second collection of sample color points being disposed on the surface of the second hull or within the volume defined thereby; c) combining the first and second hulls thereby to create a plurality of boundary surfaces collectively defining a third hull in the color space representing a region of overlap of the first and second gamuts, such that each point disposed on the surface of the third hull or within the volume enclosed thereby representing a color that is within both the first and the second color gamuts.

Claim 14

11 . A computer-implemented method for comparing a first color gamut able to be produced by a color generating apparatus upon a given medium with a second color gamut, the method comprising the steps of: a) using a first collection of sample color points to create a plurality of boundary surfaces collectively defining a first hull in the color space, each sample color point in the first collection defining a location in at least a three-dimensional color space and corresponding to a color in the first color gamut, the set of all of the points disposed on the surface of the first hull or within the volume enclosed thereby representing the color gamut able to be produced by the color generating apparatus, all of the color points in the first collection of sample color points being disposed on the surface of the first hull or within the volume defined thereby; b) using a second collection of sample color points to create a plurality of boundary surfaces collectively defining a second hull in the color space, each sample color point in the second collection defining a location in at least a three-dimensional color space and corresponding to a color in the second color gamut, the set of all of the points disposed on the surface of the second hull or within the volume enclosed thereby representing the second color gamut, all of the color points in the second collection of sample color points being disposed on the surface of the second hull or within the volume defined thereby; c) combining the first and second hulls thereby to create a plurality of boundary surfaces collectively defining a third hull in the color space representing a region of overlap of the first and second gamuts, such that each point disposed on the surface of the third hull or within the volume enclosed thereby representing a color that is within both the first and the second color gamuts.

Claim 15

12 . The computer-implemented method of claim 11 comprising the step of: d) displaying on a two-dimensional display apparatus a visual representation of at least one of the first, second or third hulls.

Claim 16

13 . The computer-implemented method of claim 12 wherein any or all of the color, opacity, or orientation of the two-dimensional display of any of the hulls is selectably controllable.

Claim 17

14 . The method of claim 11 wherein the first collection of sample color points is derived from a screen color printing apparatus; and wherein the second collection of sample color points is derived from an ink jet color printing apparatus; and wherein the each point disposed on the surface of the third hull or within the volume enclosed thereby represents a color that lies within the gamut of both the ink jet color printing apparatus and the screen color printing apparatus.

Claim 18

15 . The method of claim 11 wherein the first collection of sample color points is derived from an ink jet color printing apparatus having a first palette of N number of colored inks; and wherein the second collection of sample color points is derived from the same ink jet color printing apparatus using a second palette of M number of colored inks, where N and M are the same or different numbers; and wherein the each point disposed on the surface of the third hull or within the volume enclosed thereby represents a color that lies within both the gamut of ink jet color printing apparatus having the palette of N number of colored inks and within the gamut of the ink jet color printing apparatus having the palette of M number of colored inks.

Claim 19

16 . The method of claim 15 wherein the number of colored inks in the second palette are included within the N number of colored inks of the first palette.

Claim 20

17 . The method of claim 15 wherein at least one of the M number of colored inks in the second palette is not included within the N number of colored inks of the first palette.

Claim 21

18 . The method of claim 15 wherein none of the N number of colored inks in the second palette is included within the N number of colored inks of the first palette.

Claim 22

19 . The method of claim 11 wherein the first collection of sample color points is derived from a first ink jet color printing apparatus having a first palette of N number of colored inks; and wherein the second collection of sample color points is derived from a second ink jet color printing apparatus using a second palette comprising a M number of colored inks; and wherein the each point disposed on the surface of the third hull or within the volume enclosed thereby represents a color that lies within both the gamut of ink jet color printing apparatus having the palette of N number of colored inks and within the gamut of the ink jet color printing apparatus having the palette of M number of colored inks.

Claim 23

20 . The method of claim 19 wherein the M number of colored inks in the second palette are included within the N number of colored inks of the first palette.

Claim 24

21 . The method of claim 19 wherein at least one of the N number of colored inks in the second palette is not included within the N number of colored inks of the first palette.

Claim 25

22 . The method of claim 19 wherein none of the M number of colored inks in the second palette is included within the N number of colored inks of the first palette.

Claim 26

23 . The method of claim 11 wherein both the first and the second hulls are convex hulls.

Claim 27

24 . The computer-implemented method of claim 11 wherein at least one of the first or second hulls is an alpha hull.

Claim 28

25 . The method of claim 11 wherein the color space is the three-dimensional CIE L*a*b* system color space.

Claim 29

26 . The method of claim 25 wherein at least the first collection of sample color points is generated using the steps of: using the color generating apparatus, printing upon a given medium a plurality of sample colors; measuring the reflectance of each of the sample colors; and converting the measured reflectances into coordinates in the three-dimensional CIE L*a*b* system color space.

Claim 30

27 . The method of claim 11 further comprising the steps of: d) determining the volume enclosed by the first hull; and e) determining the volume enclosed by the third hull; and f) comparing the volumes of the first and third hulls thereby to provide an indication of the extent to which the second color gamut overlaps the first color gamut.

Claim 31

28 . The method of claim 11 further comprising the steps of: d) determining the volume enclosed by the second hull; and e) determining the volume enclosed by the third hull; and f) comparing the volumes of the second and third hulls thereby to provide an indication of the extent to which the first color gamut overlaps the second color gamut.

Claim 32

29 . The computer-implemented method of claim 11 wherein the combining step is implemented using at least one Boolean operation.

Claim 33

30 . The computer-implemented method of claim 29 wherein the Boolean operation is intersection.

Claim 34

31 . A computer-implemented method for comparing a first color gamut able to be produced by a color generating apparatus upon a given medium with a second color gamut, the method comprising the steps of: a) using a first collection of sample color points to create a plurality of boundary surfaces collectively defining a first hull in the color space, each sample color point in the first collection defining a location in at least a three-dimensional color space and corresponding to a color in the first color gamut, the set of all of the points disposed on the surface of the first hull or within the volume enclosed thereby representing the color gamut able to be produced by the color generating apparatus, all of the color points in the first collection of sample color points being disposed on the surface of the first hull or within the volume defined thereby; b) using a second collection of sample color points to create a plurality of boundary surfaces collectively defining a second hull in the color space, each sample color point in the second collection defining a location in at least a three-dimensional color space and corresponding to a color in the second color gamut, the set of all of the points disposed on the surface of the second hull or within the volume enclosed thereby representing the second color gamut, all of the color points in the second collection of sample color points being disposed on the surface of the second hull or within the volume defined thereby; c) combining the first and second hulls thereby to create a plurality of boundary surfaces collectively defining a third hull in the color space representing at least one region of exclusion of the first and second gamuts, such that each point disposed on the surface of or within the volume enclosed by the third hull representing a color that is within the first gamut but not within the second color gamut.

Claim 35

31 . A computer-implemented method for comparing a first color gamut able to be produced by a color generating apparatus upon a given medium with a second color gamut, the method comprising the steps of: a) using a first collection of sample color points to create a plurality of boundary surfaces collectively defining a first hull in the color space, each sample color point in the first collection defining a location in at least a three-dimensional color space and corresponding to a color in the first color gamut, the set of all of the points disposed on the surface of the first hull or within the volume enclosed thereby representing the color gamut able to be produced by the color generating apparatus, all of the color points in the first collection of sample color points being disposed on the surface of the first hull or within the volume defined thereby; b) using a second collection of sample color points to create a plurality of boundary surfaces collectively defining a second hull in the color space, each sample color point in the second collection defining a location in at least a three-dimensional color space and corresponding to a color in the second color gamut, the set of all of the points disposed on the surface of the second hull or within the volume enclosed thereby representing the second color gamut, all of the color points in the second collection of sample color points being disposed on the surface of the second hull or within the volume defined thereby; c) combining the first and second hulls thereby to create a plurality of boundary surfaces collectively defining a third hull in the color space representing at least one region of exclusion of the first and second gamuts, such that each point disposed on the surface of or within the volume enclosed by the third hull representing a color that is within the first gamut but not within the second color gamut.

Claim 36

32 . The computer-implemented method of claim 31 comprising the step of: d) displaying on a two-dimensional display apparatus a visual representation of at least one of the first, second or third hulls.

Claim 37

33 . The computer-implemented method of claim 32 wherein any or all of the color, opacity, or orientation of the two-dimensional display of any of the hulls is selectably controllable.

Claim 38

34 . The method of claim 31 wherein the first collection of sample color points is derived from a screen color printing apparatus; and wherein the second collection of sample color points is derived from an ink jet color printing apparatus; and wherein each point disposed on the surface of or within the volume enclosed by the third hull represents a color that is within the first gamut but not within the second color gamut.

Claim 39

35 . The method of claim 31 wherein the first collection of sample color points is derived from an ink jet color printing apparatus having a first palette of N number of colored inks; and wherein the second collection of sample color points is derived from the same ink jet color printing apparatus using a second palette of M number of colored inks, where N and M are the same or different numbers; and wherein each point disposed on the surface of or within the volume enclosed by the third hull represents a color that is within the gamut of ink jet color printing apparatus having the palette of N number of colored inks but not within the gamut of the ink jet color printing apparatus having the palette of M number of colored inks.

Claim 40

36 . The method of claim 35 wherein the number of colored inks in the second palette are included within the N number of colored inks of the first palette.

Claim 41

37 . The method of claim 35 wherein at least one of the M number of colored inks in the second palette is not included within the N number of colored inks of the first palette.

Claim 42

38 . The method of claim 35 wherein none of the N number of colored inks in the second palette is included within the N number of colored inks of the first palette.

Claim 43

40 . The method of claim 31 wherein the first collection of sample color points is derived from a first ink jet color printing apparatus having a first palette of N number of colored inks; and wherein the second collection of sample color points is derived from a second ink jet color printing apparatus using a second palette comprising a M number of colored inks; and wherein each point disposed on the surface of or within the volume enclosed by the third hull represents a color that is within the gamut of ink jet color printing apparatus having the palette of N number of colored inks but not within the gamut of the ink jet color printing apparatus having the palette of M number of colored inks.

Claim 44

41 . The method of claim 40 wherein the M number of colored inks in the second palette are included within the N number of colored inks of the first palette.

Claim 45

42 . The method of claim 40 wherein at least one of the N number of colored inks in the second palette is not included within the N number of colored inks of the first palette.

Claim 46

43 . The method of claim 40 wherein none of the M number of colored inks in the second palette is included within the N number of colored inks of the first palette.

Claim 47

44 . The method of claim 31 wherein both the first and the second hulls are convex hulls.

Claim 48

45 . The method of claim 31 wherein the color space is the three-dimensional CIE L*a*b* system color space.

Claim 49

46 . The method of claim 45 wherein at least the first collection of sample color points is generated using the steps of: using the color generating apparatus, printing upon a given medium a plurality of sample colors; measuring the reflectance of each of the sample colors; and converting the measured reflectances into coordinates in the three-dimensional CIE L*a*b* system color space.

Claim 50

47 . The method of claim 31 further comprising the steps of: d) determining the volume enclosed by the first hull; e) determining the volume enclosed by the third hull; and f) comparing the volumes of the first and third hulls.

Claim 51

48 . The method of claim 47 further comprising the steps of: g) determining the volume enclosed by the second hull; and h) comparing the volumes of the second and third hulls.

Claim 52

49 . The computer-implemented method of claim 31 wherein the combining step is implemented using at least one Boolean operation.

Claim 53

50 . The computer-implemented method of claim 49 wherein the Boolean operation is the difference operation.

Claim 54

51 . A computer-implemented method for comparing a first color gamut able to be produced by a color generating apparatus upon a given medium with a second color gamut, the method comprising the steps of: a) using a first collection of sample color points to create a plurality of boundary surfaces collectively defining a first hull in the color space, each sample color point in the first collection defining a location in at least a three-dimensional color space and corresponding to a color in the first color gamut, the set of all of the points disposed on the surface of the first hull or within the volume enclosed thereby representing the color gamut able to be produced by the color generating apparatus, all of the color points in the first collection of sample color points being disposed on the surface of the hull or within the volume defined thereby; b) using a second collection of sample color points to create a plurality of boundary surfaces collectively defining a second hull in the color space, each sample color point in the second collection defining a location in at least a three-dimensional color space and corresponding to a color in the second color gamut, the set of all of the points disposed on the surface of the second confining hull or within the volume enclosed thereby representing the second color gamut, all of the color points in the second collection of sample color points being disposed on the surface of the second hull or within the volume defined thereby; c) for each of a plurality of locations along a predetermined reference line in the color space, generating a visual display of the contour in a plane perpendicular to that reference line that is produced by the intersection of one or both the first and the second hulls with that plane, thereby to ascertain qualitatively the degree of alignment of the first and second hulls along the reference line.

Claim 55

51 . A computer-implemented method for comparing a first color gamut able to be produced by a color generating apparatus upon a given medium with a second color gamut, the method comprising the steps of: a) using a first collection of sample color points to create a plurality of boundary surfaces collectively defining a first hull in the color space, each sample color point in the first collection defining a location in at least a three-dimensional color space and corresponding to a color in the first color gamut, the set of all of the points disposed on the surface of the first hull or within the volume enclosed thereby representing the color gamut able to be produced by the color generating apparatus, all of the color points in the first collection of sample color points being disposed on the surface of the hull or within the volume defined thereby; b) using a second collection of sample color points to create a plurality of boundary surfaces collectively defining a second hull in the color space, each sample color point in the second collection defining a location in at least a three-dimensional color space and corresponding to a color in the second color gamut, the set of all of the points disposed on the surface of the second confining hull or within the volume enclosed thereby representing the second color gamut, all of the color points in the second collection of sample color points being disposed on the surface of the second hull or within the volume defined thereby; c) for each of a plurality of locations along a predetermined reference line in the color space, generating a visual display of the contour in a plane perpendicular to that reference line that is produced by the intersection of one or both the first and the second hulls with that plane, thereby to ascertain qualitatively the degree of alignment of the first and second hulls along the reference line.

Claim 56

52 . A computer-implemented method for determining whether a predetermined candidate color corresponding to a predetermined color point in at least a three-dimensional color space lies within a color gamut able to be produced by a color generating apparatus upon a given medium, the method comprising the steps of: a) using a first collection of sample color points to create a plurality of boundary surfaces collectively defining a first hull in the color space, each sample color point in the first collection defining a location in at least a three-dimensional color space and corresponding to a color in the first color gamut, the set of all of the points disposed on the surface of the hull or within the volume enclosed thereby representing the color gamut able to be produced by the color generating apparatus; and b) determining whether the point in the color space corresponding to the predetermined candidate color lies on the surface of the hull or within the volume defined thereby.

Claim 57

52 . A computer-implemented method for determining whether a predetermined candidate color corresponding to a predetermined color point in at least a three-dimensional color space lies within a color gamut able to be produced by a color generating apparatus upon a given medium, the method comprising the steps of: a) using a first collection of sample color points to create a plurality of boundary surfaces collectively defining a first hull in the color space, each sample color point in the first collection defining a location in at least a three-dimensional color space and corresponding to a color in the first color gamut, the set of all of the points disposed on the surface of the hull or within the volume enclosed thereby representing the color gamut able to be produced by the color generating apparatus; and b) determining whether the point in the color space corresponding to the predetermined candidate color lies on the surface of the hull or within the volume defined thereby.

Claim 58

53 . The computer-implemented method of claim 52 further comprising the step of: prior to the determination, scaling the collection of sample color points and the predetermined color point using a scale factor determined in accordance with the values in the color space of the sample color points and the value in the color space of the predetermined color point.