Realistic video color display

• US 7,639,255 B2
• Filed: 10/27/2006
• Issued: 12/29/2009
• Est. Priority Date: 10/28/2005
• Status: Active Grant

• Current Assignee: Axalta Coating Systems Ip Co Llc (Axalta Coating Systems Ltd.)
• Original Assignee: E. I. du Pont de Nemours and Company (Corteva, Inc.)
• Inventors: Steenhoek, Larry Eugene, Owens, Aaron J., Rodrigues, Allan Blase Joseph, Canning, Robert Vincent Jr., Benton, Daniel A., Brosmer, Gerard T.
• Primary Examiner(s): Sajous; Wesner
• Application Number:
  US11/588,471
• Publication Number:
  US 20070097119A1
• Time in Patent Office: 1,159 Days
• Field of Search: 345426-428, 345581-583, 345586-589, 345/593, 345/597, 345/643, 345600-610, 345618-619, 345/649, 345/549, 345657-659, 358515-525, 382/162, 382/167, 382/254, 382/274, 382/276, 382/300, 356402-405, 702/1, 702150-151, 702/179, 702/193, 427/8, 427/469, 427/500
• US Class Current: 345/428
• CPC Class Codes: C09D 5/36 Pearl essence, e.g. coatings containing platelet-like pigments for pearl lustre
• CPC Class Codes: C09D 7/80 Processes for incorporating ingredients
• 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 3/504 Goniometric colour measurements, for example measurements of metallic or flake based paints
• CPC Class Codes: G06T 11/001 Texturing; Colouring; Generation of texture or colour inpainting G06T5/77

Abstract

A computer-implemented method for displaying on a color display device a realistic color of a paint coating comprising the following steps: (A) identify L*, a* b* color values at least three different angles for a paint coating from a data base; (B) convert the at least three angle L*, a* b* color values to tristimulus X, Y, Z values; (C) develop continuous function equation for each tristimulus X, Y, Z values vs. aspecular angle via computer implementation and calculate the range of angles to be displayed; (D) calculate a range of aspecular angles required to display the object; (E) calculate R,G,B values from tristimulus values over the range of aspecular angles and determine maximum saturation of R,G,B values and bring into range allowed by color display device; (F) determine statistical texture function of paint coating to be simulated; and (G) apply statistical texture function to the R,G,B values of step (E) and display color pixels on color display device to show realistic color of paint coating.

Claims

1. A computer-implemented method for displaying on a color display device a realistic color of a paint coating, said method comprising the following steps:

(A) identifying L*, a* b* color values at least three different angles for a paint coating from a data base containing said values at the at least three angles or by measuring said color values of a paint coating at least three angles;

(B) converting the at least three angle L*, a* b* color values to tristimulus X, Y, Z values;

(C) developing a continuous function equation for each of the tristimulus X, Y, Z values vs. aspecular angle via computer implementation using solid color curve fitting or metallic color curve fitting techniques and calculating the range of angles to be displayed;

(D) calculating a range of aspecular angles required to display an object being rendered under the chosen orientation of object, light source and viewer;

(E) calculating R,G,B values from the tristimulus values over the range of aspecular angles and determining maximum saturation of R,G,B values and in the event the maximum R,G,B values are all less than the maximum R,G,B values allowed for the color display device being used to view color resulting from the R,G,B values proceed to step (F), in the event the R,G,B values are greater than or equal to the maximum R,G,B values allowed for the color display device being used return to step (B) and multiply the X, Y, Z values by a normalization coefficient of less than 1 and iterate steps (C), (D) and (E) to determine the maximum normalization coefficient that prevents the R,G,B values of the color to be equal to or exceed the allowable R,G,B values for the color display device being used;

(F) determining statistical texture function from a searchable data base, or generate a texture function from instrumental measurements of the paint coating to be simulated; and

(G) applying the statistical texture function to the R,G,B values of step (E) to modify said values and display color pixels on the color display device based on the modified R,G,B values to show the realistic color of the paint coating.

2. The computer implemented process of claim 1 wherein the color display device is a color video monitor.

3. The computer implemented process of claim 2 wherein multiple similar colors are generated and where the same factor, to prevent the R,G,B values from equaling or exceeding the maximum R,G,B values for the display device being used is applied to all of the similar colors so that they can be properly compared one to another.

4. The computer implemented process of claim 2 wherein three angles are used in step (1) and subsequent steps.

5. The computer implemented process of claim 3 adapted with the use of algorithms to simulate the blending of at least two colored coating compositions to form a coating color having the desired R,G,B values to determine if the two colored coating composition are blendable to prepare a desired color of the resulting coating composition.

6. The computer implemented process of claim 1 wherein the resulting realistic color of the paint is a color standard for a color coating comparison.

7. The computer implemented process of claim 3 wherein the resulting realistic color of the paint is used to select between alternate suggested paint formulas to match a standard paint color.

8. The computer implemented process of claim 3 wherein the resulting realistic color of the paint is used to monitor the computer shading of a paint formula to better match a color standard and when to stop shading of the paint.

9. The computer implemented process of claim 4 where the three angles used are aspecular angles of 15, 45 and 110 degrees.

10. The computer implemented process of claim 1 where texture function is determined from data gathered by a flatbed scanning device.

11. The computer implemented process of claim 1 where texture function is determined from data gathered by a wand type scanner.

12. The computer implemented process of claim 1 where texture function is determined from data gathered by an electronic camera.

13. The computer implemented process of claim 1 where texture function is determined from data gathered by an instrument specifically designed to determine texture information.

14. The computer implemented process of claim 1 where intensity of specular highlights is artificially reduced by limiting the range of specular angles.

15. The computer implemented process of claim 1 whereby color blending of a paint coating utilizing at least two colors is simulated by interpolating across an object being rendered from X, Y, Z values for one color of the blend to the X, Y, Z values for the second color of the blend.

16. The computer implemented process of claim 15 where the X, Y, Z interpolation from one color to the other is linear.

17. The computer implemented process of claim 15 where the X, Y, Z interpolation from one color to the other is non-linear.

18. The computer implemented process of claim 1 whereby the realistic color of the paint coating is utilized in styling of vehicles.

19. A system for displaying on a color display device a realistic color of a paint coating, said system comprising

(1) a computing device;

(2) a computer readable program which causes an operator and the computing devise to perform the following;

(A) identifying L*, a* b* color values at least three different angles for a paint coating from a data base containing said values at the at least three angles or by measuring said color values of a paint coating at least three angles;

(B) converting the at least three angle L*, a* b* color values to tristimulus X, Y, Z values;

(C) developing a continuous function equation for each of the tristimulus X, Y, Z values vs. aspecular angle via computer implementation using solid color curve fitting or metallic color curve fitting techniques and calculating the range of angles to be displayed;

(D) calculating a range of aspecular angles required to display the object being rendered under the chosen orientation of object, light source and viewer;

(E) calculating R,G,B values from the tristimulus values over the range of aspecular angles and determining maximum saturation of R,G,B values and in the event the maximum R,G,B values are all less than the maximum R,G,B values allowed for the color display device being used to view color resulting from the R,G,B values proceed to step (F), in the event the R,G,B values are greater than or equal to the maximum R,G,B values allowed for the color display device being used return to step (B) and multiply the X, Y, Z values by a normalization coefficient of less than 1 and iterate steps (C), (D) and (E) to determine the maximum normalization coefficient that prevents the R,G,B values of the color to be equal to or exceed the allowable R,G,B values for the color display device being used;

(F) determining statistical texture function from a searchable data base, or generate a texture function from instrumental measurements of the paint coating to be simulated; and

(G) applying the statistical texture function to the R,G,B values of step (E) to modify said values and display color pixels on the color display device based on the modified R,G,B values to show the realistic color of the paint coating.

20. The system of claim 19 wherein the color display device is a color video monitor.