Predictive simulation of heather fabric appearance

• US 5,680,333 A
• Filed: 09/28/1995
• Issued: 10/21/1997
• Est. Priority Date: 09/28/1995
• Status: Expired due to Fees

• Current Assignee: Invista North America Sarl (Invista)
• Original Assignee: E. I. du Pont de Nemours and Company (Corteva, Inc.)
• Inventors: Jansson, Peter Allan
• Primary Examiner(s): Teska, Kevin J.
• Assistant Examiner(s): Walker, Tyrone V.
• Application Number:
  US08/535,694
• Time in Patent Office: 754 Days
• Field of Search: 364/578, 364/470.01, 364/470.02, 364/470.03, 364/470.13, 364/470.12, 395/129, 395/130, 395/131, 382/111, 264/103
• US Class Current: 703/6
• CPC Class Codes: G05B 17/02 electric
• CPC Class Codes: G06F 2113/12 Cloth
• CPC Class Codes: G06F 30/20 Design optimisation, verification or simulation optimisation, verification or simulation of circuit designs G06F30/30
• CPC Class Codes: G06T 11/001 Texturing; Colouring; Generation of texture or colour inpainting G06T5/77

Abstract

A computer-aided method and an apparatus generates and displays, on a display device, an accurate predictive simulation of the appearance of a color pattern of a hypothetical heather yarn fabric, such as a tufted carpet, comprised of multiple candidate heather yarn components. Starting from a set of user-selected initial conditions a model is generated representing the appearance of a hypothetical heather yarn and the appearance that would be imparted to a hypothetical fabric made from that yarn. Parameters are incorporated into the model that relate appearance properties to actual yarn manufacturing process conditions. The resulting simulated-color coordinates are transformed into the typically radiometrically nonlinear color space of the particular display device to permit the colors to be accurately displayed so as to be properly perceptible to a viewer.

Claims

1. A computer-aided method for predictively simulating and displaying on a display device a color pattern of a hypothetical fabric made of heather yarn which comprises multiple candidate yarn components, the heather yarn imparting appearance properties to the hypothetical fabric, said method comprising the steps of:

a) selecting a plurality of heathering process parameters including at least;

i) the number of candidate yarn components,

ii) the color of each candidate yarn component,

iii) at least one factor governing the mixing of the candidate yarn components, and

iv) at least one factor governing the rotational relationship of the candidate yarn components as a function of distance along the yarn axis;

b) for each predetermined picture element of the color pattern of the hypothetical fabric, computing a set of simulated-color coordinate values representative of a mixture of the colors of the candidate yarn components that contribute to the apparent color perceptible at a yarn angle;

c) for each predetermined picture dement of the color pattern of the hypothetical fabric, generating a set of display device amplitude values corresponding to the color coordinate values for that picture element, and

d) outputting the set of display device amplitude values to the display device, thereby causing said device to display the simulated color of that picture element.

2. The method of claim 1 wherein step b) farther includes generating a yarn-angle value selected in accordance with the rotational relationship factor, and in accordance with the yarn-angle value, computing the set of simulated-color coordinate values.

3. The method of claim 1 wherein step a) is performed by the selection of a heathering process which implicitly denotes a predetermined set of heathering process parameters.

4. The method of claim 1 wherein step a) is performed by the explicit selection of each individual heathering process parameter.

5. The method of claim 4 wherein the color of each candidate yarn component is selected from a menu having a predetermined plurality of colors listed therein.

6. The method of claim 4 wherein the color of each candidate yarn component is selected from a color palette on a display, the display having a predetermined plurality of colors displayable thereon.

7. The method of claim 1 wherein the selection oft he color of each candidate yarn component in step a) ii) is performed by specifying the color coordinates in a radiometrically linear color space.

8. The method of claim 1 wherein the selection of the color of each candidate yarn component in step a) ii) is performed by specifying color coordinates in a radiometrically non-linear color space, the method further comprising the steps of:

i) transforming the radiometrically non-linear color coordinates to a radiometrically linear color space, and

ii) using the radiometrically linear coordinates in the computation of the simulated color coordinate value of step b).

9. The method of claim 1 wherein each candidate yarn component of the heather yarn is uncolored, and wherein the selection of the color of each candidate yarn component in step a) ii) is performed by specifying the colorant to be subsequently applied each yarn component, each candidate yarn component having a predetermined susceptibility to a specific colorant.

10. The method of claim 9 wherein the susceptibility of each uncolored candidate yarn component to at least one colorant is determined by the chemical or physical properties of the candidate yarn component and of the colorant.

11. The method of claim 1 wherein the yarn-angle of step b) is generated in accordance with a predetermined filter function applied to n adjacent yarn angles in a series of N yarn angles generated from N random numbers, where 1<

n<

N.

12. The method of claim 1 wherein step b) is generated in accordance with a predetermined filter function applied to n adjacent yearn angles in a series of N yarn angles generated from N random numbers, where 1<

n<

N to specify incremental changes in yarn angle with distance along the yarn axis.

13. The method of claim 1 wherein the a predetermined filter function is a moving average of n adjacent numbers in a series of N random numbers, where 1<

n<

N.

14. The method of claim 1 wherein the simulated-color coordinate values of step b) are computed in accordance with both the yarn-angle and the mixing factor.

15. The method of claim 1 wherein step b) further comprises generating a light-scattering value simulating the effects of multiple light scattering between candidate yarn components in accordance with the yarn-angle value, and using that generated light-scattering value to compute the color coordinate values.

16. The method of claim 1 wherein the at least one factor governing the mixing of the candidate yarn components is selected from i) a factor representing the degree of mixing of the candidate yarn components, and ii) a factor representing the variation of mixing of the candidate yarn components as a function of distance along the yarn axis.

17. The method of claim 1 wherein the at least one factor governing the mixing of the candidate yarn components includes both i) a factor representing the degree of mixing of the candidate yarn components, and ii) a factor representing the variation of mixing of the candidate yarn components as a function of distance along the yarn axis.

18. The method of claim 1 wherein the at least one factor governing the rotational relationship of the candidate yarn components as a function of distance along the yarn axis is selected from i) a factor representing a degree of serial correlation and ii) a gain factor representing a rate of rotation of the candidate yarn components.

19. The method of claim 1 further comprising the step of simulating a fabric texture.

20. The method of claim 1 further comprising the step e) of repeating steps b) through d) to generate and display the simulated-color coordinate values for each of a plurality of adjacent picture elements thereby to define a yarn traverse across a fabric.

21. The method of claim 20 wherein the hypothetical fabric is a tufted carpet fabric and wherein each yarn traverse comprises a tuft row.

22. The method of claim 21 further comprising the steps of selecting a raft simulation method and a tuft type.

23. The method of claim 20 further comprising the step f) of repeating steps b) through e) to generate and display the simulated-color coordinate values for each of a plurality of yarn traverses across a hypothetical fabric thereby to define a hypothetical fabric pattern.

24. The method of claim 23 further comprising performing, after step c, the step c1) of storing the set of display device amplitude values, and wherein step d) is performed by outputting the stored display device amplitude values to the display.

25. The method of claim 24 further comprising the step of g) changing at least one heathering process parameter and repeating the steps b) through f) sequentially to store a second hypothetical fabric pattern, and thereafter outputting the first and second stored hypothetical fabric patterns to the display device simultaneously to enable comparison of visual effects of different heathering process parameters on the color pattern of hypothetical fabrics.

26. The method of claim 1 wherein the set of simulated-color coordinate values of step b) is computed by combining the colors oft he candidate yarn components that contribute to the apparent color on a wavelength-by-wavelength basis.

27. The method of claim 1 wherein the computation of step b) further comprises using at least one look-up table yielding color-coordinates as a function of yarn angle in computing the set of simulated-color coordinate values.

28. Apparatus for predictively simulating and displaying on a display device a color pattern of a hypothetical fabric made of heather yarn comprised of multiple candidate yarn components, the heather yarn imparting appearance properties to the hypothetical fabric, said apparatus comprising:

a) means for generating signals representative of each of a plurality of operator-selected heathering process parameters including at least;

i) the number of candidate yarn components,

ii) the color of each candidate yarn component,

iii) at least one factor governing the mixing of the candidate yarn components, and

iv) at least one factor governing the rotational relationship of the candidate yarn components as a function of distance along the yarn axis;

b) means responsive to the rotational relationship factor for generating, for each predetermined picture element of the color pattern of the fabric, a yarn-angle value;

c) means responsive to the yarn-angle value for computing a set of simulated-color coordinate values representative of a mixture of the colors of the candidate yarn components that contribute to the apparent color perceptible at that yarn angle;

d) means for generating a set of display device amplitude values corresponding to the color coordinate values corresponding to the simulated color value for each predetermined picture element of the color pattern of the hypothetical fabric.

29. Apparatus of claim 28 wherein the color of each candidate yarn component is specified by color coordinates in a radiometrically non-linear color space, and wherein the means for computing a set of simulated-color coordinate values further comprises means for transforming the radiometrically non-linear color coordinates to a radiometrically linear color space, and such that the computation of the simulated-color coordinate values is performed in a radiometrically linear color space.

30. Apparatus of claim 28 wherein the means for generating a yarn-angle value includes means for generating a predetermined filter function applied to n adjacent yarn angles in a series of N yarn angles generated from N random numbers, where 1<

n<

N.

31. Apparatus of claim 28 wherein the means for generating a yarn-angle value includes means for generating a predetermined filter function applied to n adjacent yarn angles in a series of N yarn angles generated from N random numbers, where 1<

n<

N where the random numbers specify incremental changes in yarn angle with distance along the yarn axis.

32. Apparatus of claim 31 wherein the a predetermined filter function is a moving average of n adjacent numbers in a series of N random numbers, where 1<

n<

N.

33. Apparatus of claim 28 wherein the means for generating a yarn-angle value further comprises means for simulating the effects of multiple light scattering between candidate yarn components in accordance with the yarn-angle value, and means for using that generated light-scattering value to compute the color coordinate values.

34. Apparatus of claim 28 further comprising means for storing the generated display device amplitude value.