PROCESS FOR PREPARING A COLOUR CHART

• US 20160231173A1
• Filed: 09/22/2014
• Published: 08/11/2016
• Est. Priority Date: 09/25/2013
• Status: Abandoned Application

• Current Assignee: AKZO Nobel Coatings International BV (Nouryon BV)
• Original Assignee: AKZO Nobel Coatings International BV (Nouryon BV)
• Inventors: PANJA, Debabrata
• Application Number:
  US15/023,048
• Publication Number:
  US 20160231173A1
• Time in Patent Office: Days
• US Class Current: 1/1
• 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 3/465 taking into account the colour perception of the eye; using tristimulus detection
• CPC Class Codes: G01J 3/52 using colour charts

Abstract

The invention relates to a process for arranging a plurality of colours or coloured objects in a defined sequence so that each colour or coloured object has at least one neighbouring colour or coloured object, comprising the steps of a) assigning all colours or coloured objects a position in an at least two-dimensional colour space, b) assigning all neighbouring colours or coloured objects a colour difference value corresponding to the length of a vector connecting the neighbouring colours in the colour space, c) assigning a direction to every vector in the colour space connecting two neighbouring colours or coloured objects, d) arranging the sequence of colours or coloured objects in such a way that the overall sum of i. all colour difference values over the sequence and ii. all direction difference values of two consecutive vectors is minimized, and wherein a weight factor x is assigned to the sum of all colour difference values and a weight factor y is assigned to the sum of all direction difference values of two consecutive vectors prior to minimization of the overall sum, and wherein at least one of x and y is not zero.

Claims

1. A process for arranging a plurality of colours or coloured objects in a defined sequence so that each colour or coloured object has at least one neighbouring colour or coloured object, comprising the steps of

a) assigning all colours or coloured objects a position in an at least two-dimensional colour space,

b) assigning all neighbouring colours or coloured objects a colour difference value corresponding to the a length of a vector connecting the neighbouring colours in the colour space,

c) assigning a direction to every vector in the colour space connecting two neighbouring colours or coloured objects,

d) arranging the sequence of colours or coloured objects in such a way that an overall sum of

i. all colour difference values over the sequence and

ii. all direction difference values of two consecutive vectors

is minimized, and wherein a weight factor x is assigned to a sum of all colour difference values and a weight factor y is assigned to a sum of all direction difference values of two consecutive vectors prior to the minimization of the overall sum, and wherein at least one of x or y is not zero.

2. The process according to claim 1, wherein the colour space has at least three dimensions.

3. The process according to claim 2, wherein the colour space has the dimensions of lightness, chroma, and hue.

4. The process according to claim 2, wherein the colour space is the CIELAB colour space.

5. The process according to claim 1, wherein the process is implemented for effect colours having a coarseness value, and wherein the colour space includes the dimension coarseness.

6. The process according to claim 1, wherein neither x nor y is zero.

7. The process according to claim 1, wherein the process is implemented to produce a printed colour chart or a colour chart on an electronic colour display screen.

8. The process according to claim 1, wherein the process is implemented to arrange a plurality of painted objects.

9. The process according to claim 1, wherein the colours represent paint colours.

10. The process according to claim 9, wherein the colours represent vehicle repair paint colours.

11. A colour chart comprising a plurality of colours arranged in a sequence according to the process of claim 1.

12. An apparatus for displaying a colour chart, comprising an electronic colour display screen under the control of a computer device, and wherein the computer device is programmed to arrange a plurality of colours in a sequence according to the process of claim 1.

13. The apparatus according to claim 12, wherein the colours correspond to colours of paint recipes stored in the memory of the computer device.

14. The process according to claim 2, wherein the process is implemented for effect colours having a coarseness value, and wherein the colour space includes the dimension coarseness.

15. The process according to claim 2, wherein neither x nor y is zero.

16. The process according to claim 2, wherein the process is implemented to produce a printed colour chart or a colour chart on an electronic colour display screen.

17. The process according to claim 2, wherein the process is implemented to arrange a plurality of painted objects.

18. The process according to claim 2, wherein the colours represent paint colours.

19. The process according to claim 18, wherein the colours represent vehicle repair paint colours.

20. The process according to claim 5, wherein neither x nor y is zero.