Color mapping

Patent metadata

Field	Value
Publication number	US-10868943-B2
Application number	US-201415305271-A
Country	US
Kind code	B2
Filing date	Apr 25, 2014
Priority date	Apr 25, 2014
Publication date	Dec 15, 2020
Grant date	Dec 15, 2020

Abstract

A method for color mapping is disclosed based on obtaining a measurement of one or more characteristics of an imaging system. A set of color mappings are provided and the color mapping is selected based on the measurement. Each of the color mappings enables a mapping from a first color space to Neugebauer Primary area coverage vector space. A method for generating a color mapping is disclosed.

First claim

What is claimed is:

1. A method for generating a color mapping comprising:
selecting a resource within an imaging system, the resource corresponding to a color of the imaging system and the resource being degraded;
removing, from a non-degraded color mapping that maps color values from a first color space to a second color space and in which the resource is not degraded, a plurality of nodes referencing the color to which the degraded resource corresponds, generating an incomplete color mapping including a plurality of remaining nodes of the non-degraded color mapping;
computing a convex hull of the remaining nodes within the incomplete color mapping, the convex hull representing a gamut of the remaining nodes; and
for each node removed from the non-degraded color mapping, adding to the incomplete color mapping a replacement node that maps to a nearest point on the computed convex hull representing the gamut of the remaining nodes, generating a degraded color mapping that compensates for the degraded resource within the imaging system.

2. The method of claim 1 , wherein each color mapping comprises a look-up-table.

3. The method of claim 1 , wherein the imaging system is a color halftone printing system.

4. The method of claim 1 , wherein:
the resource comprises one of: printer pens, printer dies and printer nozzles, and
the limitation comprises one of a limitation on printing fluid usage and print nozzle usage.

5. The method of claim 1 , wherein the first color space comprises a red, green, blue (RGB) color space.

6. The method of claim 1 , wherein the resource that is degraded comprises a malfunctioning printer pen of the imaging system.

7. The method of claim 1 , wherein the resource that is degraded comprises an inadequate quantity of ink within the imaging system.

8. The method of claim 1 , wherein the resource that is degraded comprises an inoperative display element of the imaging system.

9. A method for color mapping comprising:
obtaining a measurement of characteristics of an imaging system, the measurement indicating a limitation on a resource for the imaging system, the resource corresponding to a color of the imaging system and the resource being degraded; and
selecting a degraded color mapping based on the measurement, the degraded color mapping compensating for the degraded resource within the imaging system and corresponding to a non-degraded color mapping that maps color values from a first color space to a second color space and in which the resource is not degraded,
wherein each of a plurality of nodes of the non-degraded color mapping that references the color to which the degraded resource corresponds is replaced within the degraded color mapping with a replacement node that maps to a nearest point on a convex hull of a plurality of remaining nodes of an incomplete color mapping corresponding to the non-degraded color mapping and from which the nodes referencing the color to which the degraded resource corresponds have been removed.

10. The method of claim 9 , wherein each color mapping comprises a look-up table.

11. The method of claim 9 , wherein the resource comprises a printer pen and the limitation comprises one of a limitation on printing fluid usage and print nozzle usage.

12. The method of claim 9 , wherein the first color space comprises a red, green, blue (RGB) color space.

13. The method of claim 9 , comprising alerting a user of the imaging system to a limitation of a resource in the imaging system.

14. A non-transitory machine-readable storage medium encoded with instructions for color mapping, the instructions executable by a processor of a system to cause the system to:
obtain a measurement of characteristics of an imaging system, the measurement indicating a limitation on a resource for the imaging system, the resource corresponding to a color of the imaging system and the resource being degraded; and
select a degraded color mapping based on the measurement, the degraded color mapping compensating for the degraded resource within the imaging system and corresponding to a non-degraded color mapping that maps color values from a first color space to a second color space and in which the resource is not degraded,
wherein each of a plurality of nodes of the non-degraded color mapping that references the color to which the degraded resource corresponds is replaced within the degraded color mapping with a replacement node that maps to a nearest point on a convex hull of a plurality of remaining nodes of an incomplete color mapping corresponding to the non-degraded color mapping and from which the nodes referencing the color to which the degraded resource corresponds have been removed.

Assignees

• Morovic Peter
• Morovic Jan
• Garcia Reyero Vinas Juan Manuel
• Gaston Llado David
• Hewlett Packard Development Co

Inventors

• Morovic Peter
• Morovic Jan
• Garcia Reyero Vinas Juan Manuel
• Gaston Llado David

Classifications

• H04N1/6058 Primary

  Reduction of colour to a range of reproducible colours, e.g. to ink- reproducible colour gamut · CPC title

• G01J3/46

  Measurement of colour; Colour measuring devices, e.g. colorimeters (measuring colour temperature G01J5/60) · CPC title

• H04N1/60

  Colour correction or control {(H04N1/54 takes precedence)} · CPC title

• G06K15/102

  using ink jet print heads · CPC title

• G01J3/462

  Computing operations in or between colour spaces; Colour management systems · CPC title