Color selection and/or matching in a color image

• US 20080056564A1
• Filed: 08/31/2006
• Published: 03/06/2008
• Est. Priority Date: 08/31/2006
• Status: Active Grant

• Current Assignee: Corel Corporation (Corel Holdings LP)
• Original Assignee: Corel Corporation (Corel Holdings LP)
• Inventors: Lindbloom, Bruce J.
• Granted Patent: US 8,270,709 B2
• Time in Patent Office: Days
• US Class Current: 382/162
• CPC Class Codes: G06T 11/001 Texturing; Colouring; Generation of texture or colour inpainting G06T5/77
• CPC Class Codes: G06V 10/56 relating to colour
• CPC Class Codes: H04N 1/62 Retouching, i.e. modification of isolated colours only or in isolated picture areas only
• CPC Class Codes: H04N 1/628 Memory colours, e.g. skin or sky

Abstract

A method or computer program product for color selection in a color image, including operations or instructions for selecting a base color in a base color portion of a color image; computing a perceptual color difference between the base color and a respective second color in the color image; comparing the perceptual color difference to a tolerance; and, identifying whether the color difference satisfies the tolerance.

Claims

1. A method for color selection in a color image, the method comprising:

selecting a base color in a base color portion of a color image;

computing a perceptual color difference between the base color and a respective second color in the color image;

comparing the perceptual color difference to a tolerance; and

,

identifying whether the color difference satisfies the tolerance.

2. A method according to claim 1 wherein the identifying operation identifies the respective second color as a match to the original base color when the tolerance is satisfied.

3. A method according to claim 1 wherein the identifying operation identifies the respective second color as a match to the original base color when the tolerance is satisfied, and identifies the second color as part of the base color portion of the color image.

4. A method according to claim 1 wherein the identifying operation provides for selecting by color one or both of an object or a region in the color image.

5. A method according to claim 1 wherein the respective second color is in one of a contiguous or a non-contiguous portion of the color image.

6. A method according to claim 1 wherein one or more of the selecting, computing, comparing and identifying operations are performed on a pixel-by-pixel basis.

7. A method according to claim 1 wherein one or more of the selecting, computing, comparing and identifying operations includes use of a chromaticity color system.

8. A method according to claim 1 wherein one or more of the selecting, computing, comparing and identifying operations includes use of a chromaticity color system including use of a common chromaticity coordinate.

9. A method according to claim 1 wherein one or more of the selecting, computing, comparing and identifying operations includes use of a chromaticity color system including use of one or more of a CIE xyY or CIE xy chromaticity color space, or a projective transformation of an additive, linear-energy color system.

10. A method according to claim 1 wherein the CIE xy chromaticity is computed from the CIE XYZ additive primaries as x=X/(X+Y+Z) and y=Y/(X+Y+Z).

11. A method according to claim 1 wherein one or more of the selecting, computing, comparing and identifying operations includes use of a perceptual color system.

12. A method according to claim 1 wherein one or more of the selecting, computing, comparing and identifying operations includes use of a perceptual color system including one or more of a CIE L*, CIE L*a*b* and CIE L*u*v* color space.

13. A method according to claim 1 further including using a CIE xy color space and one or both of a histogram and a chromaticity diagram.

14. A method according to claim 1 further including using a CIE xy color space and one or both of a histogram and a chromaticity diagram to identify a color concentration representative of a dominant base color.

15. A method according to claim 1 further including using a CIE xyY color space and one or both of a histogram and a chromaticity diagram to identify a color concentration representative of a dominant base color;

and further including one or more of segmenting or enclosing a color concentration.

16. A method according to claim 15 wherein the enclosing operation includes using one or more of a circle, an ellipse, a polygon or a non-smooth shape.

17. A method according to claim 15 wherein the enclosing operation includes adjusting a radius to set the tolerance.

18. A method according to claim 1 wherein one or more of the selecting, computing, comparing and identifying operations includes use of a one, two or three dimensional solution, the one, two or three dimensional solution including one of a CIE L*, CIE xy or a CIE L*a*b* color space.

19. A method according to claim 1 wherein the comparing operation is repeated with a second tolerance without a repetition of the selection or computing operations.

20. A method according to claim 1 wherein in the comparing operation, the tolerance is adjustable and re-applicable to the color difference.

21. A computer program product in a computer readable medium for use in a data processing system for executing a computer program, the computer program product comprising instructions for operating a method according to claim 1.

22. A computer program product for color selection in a color image, the computer program product comprising:

first instructions for a base color in a base color portion of a color image;

second instructions for computing a perceptual color difference between the base color and a respective second color in the color image;

third instructions for comparing the perceptual color difference to a tolerance; and

,

fourth instructions for identifying whether the color difference satisfies the tolerance.

23. A method for selecting a color in a color image, the color image having a plurality of candidate pixels, the method comprising:

selecting a reference pixel determining an original base color in a region of a color image;

computing a color difference in a pre-determined perceptual color space relative between the color value of the reference pixel and the color value of each candidate pixel in the color image;

applying a tolerance to each color difference;

setting a flag for each candidate pixel having a difference satisfying the tolerance.