Gamut-preserving color imaging
A color imaging technique includes setting a target value in a device-independent first color space and mapping the target value to a substantially complete point set in a second color space. The point set may include a plurality of points, each of which define substantially the same calorimetric value via a unique combination of colorants. After mapping the target value to a substantially complete point set, a point may be chosen. Moreover, after choosing a point in the point set, device-dependent colorant values defined by the point may be determined. In this manner, the invention may provide control over the colorants that are used to image a particular color.
1. A method comprising:
setting a target value in a device-independent first color space;
mapping the target value to a space curve in a second color space; and
representing the space curve as a collection of parametric curves.
2. The method of claim 1 , wherein the second color space is a device-dependent color space.
3. The method of claim 2 , wherein the space curve comprises a plurality of coordinates that produce the same colorimetric value.
4. The method of claim 1 , wherein the first color space is an n-dimensional color space, and the second color space is an m-dimensional color space; and
wherein m is greater than n.
5. The method of claim 1 , the method further comprising:
choosing a point on the space curve.
6. The method of claim 5 , the method further comprising:
determining a set of device-dependent colorant values defined by the point on the space curve.
7. The method of claim 6 , the method further comprising:
printing a color, the color being defined by the set of device-dependent colorant values.
8. The method of claim 1 , wherein the target value has a colorimetric value substantially equal to the colorimetric value of all points on the space curve.
9. The method of claim 1 , wherein the first color space is a three-dimensional color space.
10. The method of claim 1 , wherein the second color space is a four-dimensional color space.
11. The method of claim 10 , wherein the second color space is defined by four colors: black, magenta, cyan, and yellow.
12. The method of claim 10 , wherein the second color space is defined by four colors of the following group of colors: black, magenta, cyan, yellow, orange and green.
13. The method of claim 5 , wherein choosing a point on the point set is manually performed by an end user.
14. The method of claim 5 , wherein choosing a point on the point set is automatically performed by a machine.
15. The method of claim 14 , wherein the machine monitors at least one variable, the variable defining at least one machine operational condition; and
wherein the machine chooses a point in the point set as determined, at least in part, by the variable.
16. The method of claim 14 , wherein the machine chooses a point on the space curve based, at least in part, on a spectrally-based comparison between a first spectrum associated with the target value and a set of spectra associated with points on the space curve.
17. A method comprising:
setting a target value in a device-independent first color space, wherein the target value is a point in the device-independent first color space;
mapping the target value to a point set in a second color space, wherein the point set is a collection of points that define a space curve;
choosing a point from the point set;
determining a set of colorant values defined by the chosen point; and
generating a desired color based on said colorant values.