Method and device for determining the color appearance of color overprints

• US 20020193956A1
• Filed: 05/09/2002
• Published: 12/19/2002
• Est. Priority Date: 04/08/1997
• Status: Active Grant

• Current Assignee: Agfa Graphics Nv (Agfa-Gevaert N.V.)
• Original Assignee: Agfa Graphics Nv (Agfa-Gevaert N.V.)
• Inventors: Sundermann, Erik, Meireson, Baldewin, Van de Capelle, Jean-Pierre, Geurts, Wim
• Granted Patent: US 7,199,903 B2
• Time in Patent Office: Days
• US Class Current: 702/81
• CPC Class Codes: G01J 3/46 Measurement of colour; Colour measuring devices, e.g. colorimeters measuring colour temperature G01J5/60
• CPC Class Codes: G01J 3/462 Computing operations in or between colour spaces; Colour management systems
• CPC Class Codes: G01J 3/463 Colour matching
• CPC Class Codes: G01J 3/52 using colour charts
• CPC Class Codes: G01N 33/32 Paints; Inks
• CPC Class Codes: H04N 1/6033 using test pattern analysis H04N1/6055 takes precedence
• CPC Class Codes: H04N 1/6097 depending on the characteristics of the output medium, e.g. glossy paper, matt paper, transparency or fabrics

Abstract

A method and apparatus to predict the color of an overprint of a set of colorants at a set of respective coverage percentages on a substrate of a substrate type using a printing technique. The colorants include some for which a device profile is provided. The method includes determining the colorant parameters of the device profile colorants; determining the spectrum of the substrate, providing spectral colorant parameters for the non-device profile colorants, and determining the color of the overprint. One version including modifying the data of the device profile such that the colorant parameters determined in the step of determining colorant parameters determines the colorant parameters of modified colorants that match the color of the device profile colorants and that cover at least the gamut of the device profile colorants. In one version, the step of determining the determining the color of the overprint includes determining the coverage percentages of the modified colorants corresponding to the colorants of each subset, and using the coverage percentages of the modified colorants to determine the color of the overprint.

Claims

1. A method to predict the color of an overprint of a set of colorants at a set of respective coverage percentages on a substrate of a substrate type using a printing technique, the method comprising:

providing one or more device profiles for one or more subsets of the set of colorants for printing on the substrate with the printing technique;

determining the colorant parameters of the device profile colorants of the subsets;

determining the spectrum of the substrate;

providing the colorant parameters of the non-device profile colorants; and

determining the color of the overprint.

2. A method as recited in claim 1, further including modifying data of the one or more device profiles such that the colorant parameters determined in the step of determining colorant parameters determines the colorant parameters of modified colorants that match the color of the respective device profile colorants and that cover at least the gamut of the respective device profiles.

3. A method as recited in claim 2, wherein the step of determining the determining the color of the overprint includes determining the coverage percentages of the modified colorants corresponding to the colorants of each subset, and using the coverage percentages of the modified colorants to determine the color of the overprint.