Preserving pure primary colors in color transforms

• US 7,911,665 B1
• Filed: 05/15/2008
• Issued: 03/22/2011
• Est. Priority Date: 05/15/2008
• Status: Active Grant

• Current Assignee: Adobe Inc.
• Original Assignee: Adobe Systems Incorporated (Adobe Inc.)
• Inventors: Borg, Lars U.
• Primary Examiner(s): Williams; Kimberly A
• Application Number:
  US12/121,535
• Time in Patent Office: 1,041 Days
• Field of Search: 358/1.9, 358/515, 358/518, 358/523, 358/524, 382/162, 382/167, 345/593
• US Class Current: 358/518
• CPC Class Codes: H04N 1/6058 Reduction of colour to a range of reproducible colours, e.g. to ink- reproducible colour gamut

Abstract

The subject matter disclosed herein relates to purifying muddied primary color values of an output color space and correcting a portion of non-primary color values of the output color space so as to smoothly transition from the purified primary color values to uncorrected non-primary color values.

Claims

1. A method, comprising:

selecting one or more muddied primary color values of an output color space, wherein said one or more muddied primary color values comprise a pure color value and one or more color impurities;

determining one or more purified primary color values based at least in part on removing said one or more color impurities from said one or more muddied primary color values;

determining a correction factor based at least in part on a relation between said one or more purified primary color values and said one or more muddied primary color values; and

correcting a portion of non-primary color values of said output color space into corrected non-primary color values based at least in part on said correction factor via a computing platform.

2. The method of claim 1, further comprising determining a color correction transform capable of color management, wherein said color correction transform is based at least in part on said one or more purified primary color values and said corrected non-primary color values.

3. The method of claim 1, further comprising:

determining a look up table capable of associating color values from an input color space with corresponding color values from said output color space based at least in part on said purified primary color values and said corrected non-primary color values; and

printing and/or displaying said corresponding color values from said output color space.

4. The method of claim 1, further comprising leaving a portion of said non-primary color values of said output color space as unchanged non-primary color values.

5. The method of claim 1, further comprising:

leaving a portion of said non-primary color values of said output color space as unchanged non-primary color values; and

determining a look up table capable of associating color values from an input color space with corresponding color values in said output color space based at least in part on said purified primary color values, said corrected non-primary color values, and said unchanged non-primary color values.

6. The method of claim 1, further comprising:

leaving a portion of said non-primary color values of said output color space as unchanged non-primary color values; and

applying a smoothing correction via said corrected non-primary color values, wherein said smoothing correction decreases over a transition from said purified primary color values at an edge of said output color space to said unchanged non-primary color values.

7. The method of claim 1, wherein said relation between said one or more purified primary color values and said one or more muddied primary color values comprises a difference between said one or more purified primary color values and said one or more muddied primary color values;

and wherein said correcting is further based at least in part on a difference between said one or more non-primary color values and said one or more muddied primary color values.

8. An article comprising:

a non-transitory computer readable medium comprising machine-readable instructions stored thereon which, if executed direct a computing platform to;

select one or more muddied primary color values of an output color space, wherein said one or more muddied primary color values comprise a pure color value and one or more color impurities;

determine one or more purified primary color values based at least in part on removing said one or more color impurities from said one or more muddied primary color values;

determine a correction factor based at least in part on a relation between said one or more purified primary color values and said one or more muddied primary color values; and

correct a portion of non-primary color values of said output color space into corrected non-primary color values based at least in part on said correction factor.

9. The article of claim 8, wherein said machine-readable instructions, if executed by a computing platform, further direct a computing platform to:

determine a color correction transform capable of color management, wherein said color correction transform is based at least in part on said one or more purified primary color values and said corrected non-primary color values.

10. The article of claim 8, wherein said machine-readable instructions, if executed by a computing platform, further direct a computing platform to:

determine a look up table capable of associating color values from an input color space with corresponding color values from said output color space based at least in part on said purified primary color values and said corrected non-primary color values; and

print and/or display said corresponding color values from said output color space.

11. The article of claim 8, wherein said machine-readable instructions, if executed by a computing platform, further direct a computing platform to:

leave a portion of said non-primary color values of said output color space as unchanged non-primary color values.

12. The article of claim 8, wherein said machine-readable instructions, if executed by a computing platform, further direct a computing platform to:

leave a portion of said non-primary color values of said output color space as unchanged non-primary color values; and

determine a look up table capable of associating color values from an input color space with corresponding color values in said output color space based at least in part on said purified primary color values, said corrected non-primary color values, and said unchanged non-primary color values.

13. The article of claim 8, wherein said machine-readable instructions, if executed by a computing platform, further direct a computing platform to:

leave a portion of said non-primary color values of said output color space as unchanged non-primary color values; and

apply a smoothing correction via said corrected non-primary color values, wherein said smoothing correction decreases over a transition from said purified primary color values at an edge of said output color space to said unchanged non-primary color values.

14. The article of claim 8, wherein said relation between said one or more purified primary color values and said one or more muddied primary color values comprises a difference between said one or more purified primary color values and said one or more muddied primary color values;

and wherein said correction is further based at least in part on a difference between said one or more non-primary color values and said one or more muddied primary color values.

15. An apparatus comprising:

a computing platform, said computing platform being adapted to;

select one or more muddied primary color values of an output color space, wherein said one or more muddied primary color values comprise a pure color value and one or more color impurities;

determine one or more purified primary color values based at least in part on removing said one or more color impurities from said one or more muddied primary color values;

determine a correction factor based at least in part on a relation between said one or more purified primary color values and said one or more muddied primary color values; and

correct a portion of non-primary color values of said output color space into corrected non-primary color values based at least in part on said correction factor.

16. The apparatus of claim 15, wherein said computing platform is further adapted to:

determine a color correction transform capable of color management, wherein said color correction transform is based at least in part on said one or more purified primary color values and said corrected non-primary color values.

17. The apparatus of claim 15, wherein said computing platform is further adapted to:

determine a look up table capable of associating color values from an input color space with corresponding color values from said output color space based at least in part on said purified primary color values and said corrected non-primary color values; and

print and/or display said corresponding color values from said output color space.

18. The apparatus of claim 15, wherein said computing platform is further adapted to:

leave a portion of said non-primary color values of said output color space as unchanged non-primary color values.

19. The apparatus of claim 15, wherein said computing platform is further adapted to:

leave a portion of said non-primary color values of said output color space as unchanged non-primary color values; and

determine a look up table capable of associating color values from an input color space with corresponding color values in said output color space based at least in part on said purified primary color values, said corrected non-primary color values, and said unchanged non-primary color values.

20. The apparatus of claim 15, wherein said computing platform is further adapted to:

leave a portion of said non-primary color values of said output color space as unchanged non-primary color values; and

apply a smoothing correction via said corrected non-primary color values, wherein said smoothing correction decreases over a transition from said purified primary color values at an edge of said output color space to said unchanged non-primary color values.

21. The apparatus of claim 15, wherein said relation between said one or more purified primary color values and said one or more muddied primary color values comprises a difference between said one or more purified primary color values and said one or more muddied primary color values;

and wherein said correction is further based at least in part on a difference between said one or more non-primary color values and said one or more muddied primary color values.