Granted Patent B2

US 7,433,078 · App. 10/836,069 · Granted Oct 7, 2008

Abstract

Claims (33)

1. A system for calibrating a digital color imaging device to a printing press, the digital color imaging device comprising first and second colorants, the first colorant comprising a first shade of a color, the second colorant comprising a second shade of the color different from the first shade, the printing press comprising a color profile, the system comprising:

an image source comprising a test pattern adapted for printing by the digital color imaging device, wherein the test pattern comprises a plurality of patches, wherein each patch has a corresponding combination of amounts of the first and second colorants;

an instrument adapted to colorimetrically measure the printed test pattern; and

a processor adapted to: (a) receive colorimetric measurements from the instrument and calculate therefrom a tonal response for the digital color imaging device; (b) receive a colorimetric value from the color profile and calculate therefrom a tonal response for the printing press; (c) receive a first range of input values and a second range of input values; (d) receive an amount of the first colorant at an end of the second range of input values; (e) map the tonal response of the first colorant to the tonal response of the press to determine corresponding amounts of the first colorant for the first range of input values; (f) calculate a tonal response of the first colorant to determine corresponding amounts of the first colorant for the second range of input values; (g) create a table that provides the calculated tonal response for each combination of amounts of the first and second colorants; and (h) calculate the tonal response of the second colorant for the second range of input values by determining from the table an amount of the second colorant that when added to the corresponding amount of the first colorant has a tonal response that equals the tonal response of the printing press.

2. The system of claim 1 , wherein the digital color imaging device comprises a plurality of colorants, and the test pattern comprises a test patch having a corresponding specified percentage of the colorants.

3. The system of claim 2 , wherein the colorants comprise cyan, magenta and yellow colorants.

4. The system of claim 2 , wherein the colorants comprise cyan, magenta, yellow and black colorants.

5. The system of claim 2 , wherein the first colorant comprises a light shade of a color, and the second colorant comprises a normal shade of a color.

6. The system of claim 1 , wherein the instrument comprises a colorimeter.

7. The system of claim 1 , wherein the instrument comprises a spectrophotometer.

8. The system of claim 1 , wherein the instrument comprises a spectrocolorimeter.

9. The system of claim 1 , wherein the colorimetric measurements comprise CIELAB data values.

10. The system of claim 1 , wherein the colorimetric measurements comprise CIEXYZ data values.

11. A method for calibrating a digital color imaging device to a printing press, the digital color imaging device comprising first and second colorants, the first colorant comprising a first shade of a color, the second colorant comprising a second shade of the color different from the first shade, the printing press comprising a color profile, the method comprising:

printing a test pattern on the digital color imaging device, wherein the test pattern comprises a plurality of patches, wherein each patch has a corresponding combination of amounts of the first and second colorants;

colorimetrically measuring the printed test pattern;

receiving the measured colorimetric measurements and calculating therefrom a tonal response for the digital color imaging device;

receiving a colorimetric value from the color profile and calculating therefrom a tonal response for the printing press;

receiving a first range of input values and a second range of input values;

receiving an amount of the first colorant at an end of the second range of input values;

mapping the tonal response of the first colorant to the tonal response of the press to determine corresponding amounts of the first colorant for the first range of input values;

calculating a tonal response of the first colorant to determine corresponding amounts of the first colorant for the second range of input values;

creating a table that provides the calculated tonal response for each combination of amounts of the first and second colorants; and

calculating the tonal response of the second colorant for the second range of input values by determining from the table an amount of the second colorant that when added to the corresponding amount of the first colorant has a tonal response that equals the tonal response of the printing press.

12. The method of claim 11 , wherein the digital color imaging device comprises a plurality of colorants, and the test pattern comprises a test patch having a corresponding specified percentage of the colorants.

13. The method of claim 11 , wherein the colorants comprise cyan, magenta and yellow colorants.

14. The method of claim 11 , wherein the colorants comprise cyan, magenta, yellow and black colorants.

15. The method of claim 11 , wherein the first colorant comprises a light shade of a color, and the second colorant comprises a normal shade of a color.

16. The method of claim 11 , wherein colorimetrically measuring comprises measuring the printed test pattern using a colorimeter.

17. The method of claim 11 , wherein colorimetrically measuring comprises measuring the printed test pattern using a spectrophotometer.

18. The method of claim 11 , wherein colorimetrically measuring comprises measuring the printed test pattern using a spectrocolorimeter.

19. The method of claim 11 , wherein the colorimetric measurements comprise CIELAB data values.

20. The method of claim 11 , wherein the colorimetric measurements comprise CIEXYZ data values.

Assignments (11)