JP2020051923A - Method for setting isochromatic range for evaluating painted color and device for setting isochromatic range - Google Patents

Abstract

To set a new isochromatic range of a target color to be painted for evaluating the painted color.SOLUTION: In the chromatic coordinate system, a basic isochromatic range of a target color is statistically determined and is set on the basis of data on the isochromatic range of preset reference colors, and the basic isochromatic range of the target color is corrected on the basis of plural pieces of color data on the chromatic coordinate system of the color which a person feels the same as the target color prepared on the basis of a subjective evaluation experiment.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a target color matching range setting method and a target color matching range setting device for evaluating whether or not a paint color is a target color.

  2. Description of the Related Art In the painting of equipment such as vehicles, the color difference between an actual paint color and its target color is measured by a color difference meter to evaluate the paint color. Patent Literature 1 describes a method of systematically and quantitatively evaluating the anisotropic coating color such as metallic coating and pearl coating irrespective of hue. It classifies paint colors into absorption, reflection, and interference according to their color form, and creates pass / fail judgment criteria based on lightness and lightness difference for each classification, and evaluates pass / fail of paint colors based on these criteria. It is to do.

JP 2012-173272 A

  The evaluation method described in Patent Literature 1 is not suitable for determining the quality of a chromatic color or color matching because a paint color is evaluated only by lightness.

On the other hand, if the color difference is measured by the color difference meter, it is possible to determine the quality of the chromatic color and to perform color matching. Conventionally, in a CIE L * a * b * color coordinate system, a color difference is represented by a Euclidean distance ΔE ₇₆ = √ (Δa ² + Δb ² + ΔL ² ), and a paint color becomes a target color depending on whether or not the color difference is close to zero. It is known to evaluate whether or not there is.

However, there is a problem that the evaluation based on the color difference ΔE ₇₆ and the visual evaluation are different depending on the color. That is, it is known that the color discrimination range is a perfect circle (spherical shape) in the color difference ΔE ₇₆ , but the color discrimination range visually is elliptical.

To solve this problem, the CIE DE2000 color difference equation is known. This lightness difference [Delta] L *, chroma difference [Delta] C *, based on the hue difference [Delta] H *, heavy valence coefficient S _L, S _C, in which was subjected to weighted S _H. The color difference ΔE ₀₀ has an elliptical shape whose major axis is the saturation direction, and is similar to a color matching ellipse visually observed.

However, the color difference ΔE ₀₀ is merely an approximation to the shape of the color discrimination area visually. Color matching oval due to the color difference Delta] E ₀₀ is, for example, a color matching ellipse set by DuPont color scientist shown in FIG. 1, the size and inclination are different. Therefore, the color difference Delta] E _00, can not be expected an accurate assessment. On the other hand, the color matching ellipse data of DuPont is limited to 19 specific colors and cannot be used for evaluating other colors.

  Also, even if the color matching ellipse of the target color for coating color evaluation is set by any method, if the coating color has, for example, a contrast due to the unevenness of the surface of the object to be coated, the evaluation based on the color matching ellipse is human. Evaluation may deviate from sensation. That is, when the contrast becomes strong, the measured value of the coating color tends to deviate from the range of the color matching ellipse, but this is due to the contrast. May feel the same color.

  Therefore, the present invention provides a method and apparatus for newly setting a color matching range of a target color of a paint color for evaluating the paint color.

  According to the present invention, the color matching range of a known reference color is used for setting the color matching range of a target color, and the color matching range of the target color is corrected based on subjective evaluation experiment data.

The color matching range setting method for coating color evaluation disclosed herein is a method of setting a color matching range for evaluating whether a coating color is color matching with a target color in a color coordinate system,
In the color coordinate system, a step of statistically obtaining and setting a basic color matching range of the target color based on data on a color matching range of a plurality of reference colors,
Correcting a basic color matching range of the target color based on a plurality of color data on the color coordinate system that a person created based on a subjective evaluation experiment feels as the same color as the target color. It is characterized by the following.

  According to this, the basic color matching range of the target color is statistically set from the known color matching range data of the reference color. In this setting, visual evaluation of the target color is unnecessary. That is, the basic color matching range of the target color comparable to the color matching range of the reference color can be set without depending on the visual evaluation. Then, since the basic color matching range of the target color is corrected based on the subjective evaluation test data, it is possible to obtain, for example, color matching range data in which a person feels the same color even if there is a contrast. The reliability of the color evaluation is increased.

  The data relating to the color matching range of a plurality of reference colors includes, for example, the subjective evaluation of the color matching range for a reference color such as a color matching ellipse for a plurality of colors set by a color scientist of DuPont shown in FIG. It is preferable to include data obtained from experiments.

  Further, the color matching range data for a specific color obtained by the correction based on the statistical method and the subjective evaluation experiment data is related to the color matching range of the plurality of reference colors for obtaining the basic color matching range of the target color. Can be added to the data.

In one embodiment, the color coordinate system is a three-dimensional color space coordinate system,
The color matching range of each of the plurality of reference colors is defined by an ellipsoid,
For estimating each coefficient of the ellipsoidal expression relating to a specific reference color of the plurality of reference colors based on the corresponding coefficients of the other plurality of reference colors, specifying the coefficient relating to the other plurality of reference colors A prediction formula defined by a weighted average of the coefficients in consideration of the distance from the reference color and the tuning parameter,
The step of setting the basic color matching range of the target color includes:
Calculating a distance between the plurality of reference colors;
Predicting each of the coefficients of the plurality of reference colors by the prediction formula;
Determining a tuning parameter based on a predicted value and an actual value of the coefficient by the prediction formula,
Obtaining a calculation expression for obtaining each coefficient of the ellipsoidal expression of the target color by giving the determined tuning parameter to the prediction expression;
Obtaining an ellipsoidal expression that defines a basic color matching range of the target color by a weighted average of the coefficients for the plurality of preset reference colors, using the above calculation formula.

  According to this, it is possible to set a basic color matching range of a highly reliable and useful target color comparable to the color matching range of the reference color.

In one embodiment, the step of correcting the basic color matching range of the target color includes:
Generating a convex hull including a plurality of color data based on the subjective evaluation experiment;
Correcting each coefficient of the ellipsoidal expression by least-squares estimation so that the ellipsoid defining the basic color matching range of the target color fits the convex hull.

  According to this, highly reliable color matching range data relating to the target color can be obtained.

The color-matching range setting device for coating color evaluation disclosed herein is a device that sets a color-matching range for evaluating whether or not the coating color is the same as the target color in the color coordinate system,
Storage means for setting and storing a color matching range in the color coordinate system of each of the plurality of reference colors, a color matching range setting means for the target color, a subjective evaluation data setting means, and a color matching range correcting means; With
The target color matching range setting means statistically determines a basic color matching range of the target color based on data relating to a preset color matching range of a plurality of reference colors in the color coordinate system. Set,
The subjective evaluation data setting means sets, on the color coordinate system, a plurality of pieces of color data that a person created based on a subjective evaluation experiment feels as the same color as the target color,
The color matching range correction means corrects a basic color matching range of the target color based on the plurality of color data.

  According to this, the basic color matching range of the target color comparable to the color matching range of the reference color can be set from the known color matching range data of the reference color without depending on the visual evaluation. Then, since the basic color matching range of the target color is corrected based on the subjective evaluation experiment data, for example, even if there is a contrast, it is possible to obtain color matching range data in which a person feels the same color, and The reliability of the color evaluation is increased.

In one embodiment, the color coordinate system is a three-dimensional color space coordinate system,
The color matching range of each of the plurality of reference colors is defined by an ellipsoid,
Predicting each coefficient of an ellipsoidal expression relating to a specific reference color among the plurality of reference colors based on corresponding coefficients of the other plurality of reference colors, a specific reference for the coefficient relating to the other plurality of reference colors A prediction formula defined by a weighted average of the coefficients, taking into account the weight from the distance from the color and the tuning parameter,
The target color matching range setting means calculates a distance between the plurality of reference colors, predicts the coefficients of the plurality of reference colors by the prediction formula, and calculates a predicted value of the coefficients by the prediction formula. And a tuning parameter based on an actual value, and using a calculation formula obtained by giving the tuning parameter to the prediction formula, a weighted average of the coefficients relating to the plurality of preset reference colors is used to calculate the target color. Obtain an ellipsoid formula that defines the basic color matching range.

  According to this, it is possible to set a basic color matching range of a highly reliable and useful target color comparable to the color matching range of the reference color.

  In one embodiment, the color matching range correction means generates a convex hull including a plurality of color data based on the subjective evaluation experiment, and the ellipsoid defining a basic color matching range of the target color is a convex hull. Each coefficient of the ellipsoidal expression is corrected by the least squares estimation so as to fit.

  According to this, highly reliable color matching range data relating to the target color can be obtained.

  In one embodiment, the paint color is a paint color of a metallic paint. A coating film obtained by metallic coating has a strong optical anisotropy in which a color tone varies depending on a viewing angle. The color matching range setting method or color matching range data obtained by the color matching range setting device is useful for evaluating the coating color of a coating film having such optical anisotropy.

  In one embodiment, the metallic coating is applied to a vehicle body or exterior component of a vehicle.

  According to the present invention, it is possible to set a basic color matching range of a target color comparable to the color matching range of the reference color from the known color matching range data of the reference color without visual evaluation. Since the range is corrected based on the subjective evaluation experiment data, for example, even if there is a contrast, it is possible to obtain the same color range data in which a person feels the same color, and the reliability of the paint color evaluation increases.

FIG. 4 is a diagram illustrating distribution of a plurality of reference color equal color ranges in a color coordinate system. FIG. 2 is a block diagram illustrating a configuration example of a color matching range setting device. FIG. 9 is a processing flowchart of target color equivalent color range setting control. FIG. 9 is a diagram illustrating a distribution in a color coordinate system of a basic color matching range of a plurality of target colors having different light receiving angles set by the color matching range setting control. The figure which shows the color measurement method. FIG. 8 is an explanatory diagram of correction based on subjective evaluation data of a basic color matching range of a target color.

  Hereinafter, embodiments for carrying out the present invention will be described with reference to the drawings. The description of the preferred embodiments below is merely exemplary in nature and is not intended to limit the invention, its applications, or its uses.

The ellipsoidal plot shown in FIG. 1 shows the color matching range of 19 colors set by DuPont color scientists as a plurality of reference colors in the CIE L ^* a ^* b ^* three-dimensional color space coordinate system. . That is, the color matching range of each of the 19 colors is defined by an ellipsoid centered on each color represented by L ^* , a ^*, and b ^* . As is clear from the figure, the size, inclination, and ratio of the major axis to the minor axis of the ellipsoid indicating the color matching range differ depending on the hue and lightness.

  Therefore, in the evaluation of whether or not the paint color is the same color as the target color, as shown in FIG. 1, when the target color is a color other than the 19 colors, a color matching range of the target color is set. There is a need.

  Hereinafter, a method and an apparatus for setting the color matching range of the target color will be described. The method and apparatus for setting the color matching range are based on color matching between the paint color (target color) of the vehicle body and the paint color of the bumper when the steel plate body of the vehicle is metallic-painted and the plastic bumper is similarly metallic-painted. Useful for setting the color matching range for

<Equivalent color range setting device for paint color evaluation>
FIG. 2 shows a configuration example of the color matching range setting device. In the figure, 21 is a CPU, 22 is a display such as a CRT as a display means, 23 is a keyboard which is a data input means for target colors and subjective evaluation data, 24 is a ROM storing a boot program and the like, and 25 is a ROM. RAM as data storage means for temporarily storing various data and processing results; 26, a program for setting a color matching range of a target color, a HDD for storing color matching range data of a reference color, subjective evaluation data, etc. Is a communication interface for communicating with an external information system via a communication network, and 28 is a printer for printing processing results and the like. These components are connected via a bus 29, and the CPU 21 sets the color matching range of the target color according to a program stored in the storage device 26. The CPU 21 constitutes data acquisition means, color matching range setting means, subjective evaluation data setting means, determination means, color matching range correction means, output means, and the like.

The data acquisition means includes color coordinate system (CIE L ^* a ^* b ^* three-dimensional color space coordinate system) data, target color data, color matching range data for a plurality of reference colors, subjective evaluation data, target color, and the like. To obtain a coefficient calculation formula for setting a color range, a coefficient prediction formula or the like is obtained from the storage device 26. The color matching range setting means statistically calculates and sets a basic color matching range of the target color based on the color matching range data of the reference color in the color coordinate system. The subjective evaluation data setting means sets the subjective evaluation data on a color coordinate system. The determining means determines whether or not the subjective evaluation data is in the basic color matching range. The color matching range correcting means sets the evaluation color matching range on the color coordinate system by correcting the basic color matching range of the target color based on the subjective evaluation data when the subjective evaluation data is out of the basic color matching range. I do. The output unit outputs the basic color matching range of the target color and the color matching range for evaluation to the storage device 26 as a data file.

  A coefficient prediction formula for obtaining a calculation formula for setting a color matching range of a target color will be described. The color matching range of 19 DuPont colors as a plurality of reference colors is defined by an ellipsoid as described above. The ellipsoid can be expressed by the following polynomial (ellipsoid) (1).

a, b, and L respectively represent a ^* , b ^*, and L ^* in the color coordinate system. “G” with subscripts is a coefficient, and each has the following properties.

g ₁₁ : Change the diameter of the ellipsoid in the a direction.

g ₂₂ : Change the diameter of the ellipsoid in the b direction.

g ₃₃ : Change the diameter of the ellipsoid in the L direction.

g ₁₂ ; Change the inclination between a and b of the ellipsoid.

g ₁₃ : Change the inclination between a and L of the ellipsoid.

g ₂₃ ; Change the inclination between b and L of the ellipsoid.

  The coefficient prediction formula is a formula for predicting each coefficient of the ellipsoidal expression relating to any one of the 19 colors based on the corresponding coefficients of the remaining 18 colors, and is a weighted average of the coefficients of the ellipsoidal expression relating to the 18 colors. Is defined in The weights given to the coefficients of the ellipsoidal expression for the 18 colors are each of the 18 colors, the one color, the distance (distance between the centers of the ellipsoids) D, and the tuning parameter γ. The weight is given by an exponential function.

ID i = 1,2 in the 19 colors, when put ... 19, for example, the predicted value of the ellipsoid type coefficient g ₁₁ according to the color matching range of 19 th color, the color number 19 assigned in parentheses If expressed as? _{11 (19)} , the coefficient prediction formula (2) is as follows.

Here, _Di-19 and _Dk-19 represent the distance between the 19th color and each of the remaining 18 colors. For example, the distance D _1-19 between the _first color (a ₁ , b ₁ , L ₁ ) and the nineteenth color (a ₁₉ , b ₁₉ , L ₁₉ ) is represented by the following equation (3). (A ₁ , b ₁ , L ₁ ) and (a ₁₉ , b ₁₉ , L ₁₉ ) represent the values of the color coordinates (a, b, L) of the first color and the nineteenth color, respectively. And the color coordinates of the center of the ellipsoid representing the color matching range of each color.

Other coefficient predicted values g ′ _{22 (19)} , g ′ _{33 (19)} , g ′ _{12 (19)} , g ′ _{13 (19)} and g ′ _{23 (19)} are also g ′ _{11 (} It can be expressed by the same equation as ₁₉₎ .

  The subjective evaluation data is a plurality of color data on the color coordinate system which is created based on a subjective evaluation experiment and which a person perceives as the same color as the target color.

  If the direction of the surface of the object to be coated is changed due to unevenness of the surface or the like, contrast (brightness and darkness) appears because the direction of light reflection is different on surfaces having different directions when viewed from the viewer. That is, even if the object to be coated is uniformly coated with the same paint, the values of the color coordinates (a, b, L) will be different on surfaces having different directions. However, since this is due to contrast, even if the coordinate values of the colors are different, a person may feel the same color. Therefore, even if there is such a color difference due to the contrast, it is preferable that the paint color is evaluated as being equal to the target color.

Therefore, a plurality of test pieces whose colors are changed in consideration of the contrast are prepared, and by comparing with the target color, a color expert determines whether the color of the test pieces should be the same as the target color. Obtain evaluation results. The color of the test piece evaluated as being equal in color is measured by a colorimeter to obtain color data (a _add , b _add , L _add ). A plurality of color data obtained by the subjective evaluation experiment is stored in the storage device 26 by the input means. (A _add , b _add , L _add ) are the coordinate values of the colors evaluated as being equal to the target color by the subjective evaluation experiment.

<Target color matching range setting processing>
Next, the process of setting the color matching range of the target color performed by the color matching range setting device will be described with reference to the flowchart shown in FIG.

In step S1, the color coordinate system data, the target color data _{(a t, b t, L} t), a plurality of reference colors (19 colors) each color data _{(a i, b i, L} i) and the color matching range Data (ellipsoidal expression), subjective evaluation data (a _add , b _add , L _add ), a coefficient prediction expression for obtaining a coefficient calculation expression for setting a color matching range of a target color, and the like are obtained from the storage device 26. _{(A t, b t, L} t) is the coordinate value of the target color is a coordinate value of _{(a i, b i, L} i) each reference color (i = 1~19).

In step S2, the reference color _{(a i, b i, L} i) the distance between D _i-i and the target color _{(a t, b t, L} t) and a plurality of reference colors _{(a i, b i, L} i ) The distance D _{ti to} each of them is obtained by the same distance calculation formula as the formula (3).

  In step S3, each coefficient of an ellipsoidal expression (see equation (1)) representing the color matching range of each reference color is predicted between the reference colors. That is, assuming that the coefficient of one of the plurality of reference colors is unknown, prediction from the coefficients of the remaining reference colors is sequentially performed for all the reference colors. Hereinafter, a specific description will be given.

To predict the coefficient g _{11 (19)} of the ellipsoidal expression representing the color matching range of the _nineteenth reference color (a ₁₉ , b ₁₉ , L ₁₉ ) of the ₁₉ reference colors, use the coefficient prediction expression of Expression (2). Used. The distance D _i-19 (D _k-19 ) between the 19th reference color and each of the remaining reference colors (18 colors) and the coefficient g _{11 (i)} of each of the reference colors (18 colors ₎ are substituted into this prediction formula. Thus, a coefficient predicted value g ′ _{11 (19)} for the _nineteenth reference color is obtained by the weighted average of the distance and the tuning parameter of the coefficient g _{11 (i)} . Similarly, predicted values g ′ _{22 (19)} , g ′ _{33 (19)} , g ′ _{12 (19)} , g ′ _{13 (19)} and g ′ _{23 (19 ) of the} other coefficients relating to the nineteenth reference color ₎ . Further, the coefficient prediction values of the remaining 18 colors among the 19 reference colors are obtained in the same manner as the 19th reference color.

In step S4, for each of the coefficients g ₁₁ , g ₂₂ , g ₃₃ , g ₁₂ , g _13, and g ₂₃ of the ellipsoidal expression of Expression 2, the tuning parameter γ of the coefficient prediction expression (see Expression (2)) is obtained. That is, γ that minimizes the Kullback library pseudorange from the predicted value g ′ _{(19) of} the coefficients g ₁₁ , g ₂₂ , g ₃₃ , g ₁₂ , g _13, and g ₂₃ to the actual value g ₍₁₉₎ is obtained. The constraints in this case are as follows.

g '11 _(i) > 0
g ′ _{11 (i)} g ′ _{22 (i)} −g ′ _{12 (i)} ² > 0
g ′ _{11 (i)} g ′ _{22 (i)} g ′ _{33 (i)} +2 g ′ _{12 (i)} g ′ _{13 (i)} g ′ _{23 (i)} −g ′ _{11 (i)} g ′ _{23 (i)} ²
−g ′ _{12 (i)} ² g ′ _{33 (i)} −g ′ _{13 (i)} ² g ′ _{22 (i)} > 0

Substituting the γ obtained in step S4 into the prediction formulas of the coefficients g ₁₁ , g ₂₂ , g ₃₃ , g ₁₂ , g ₁₃ and g _23, and sets a calculation formula for calculating each coefficient of the ellipsoid formula of the target color. (Step S5). To the resulting coefficients calculation formula, the target color _{(a t, b t, L} t) and 19 of the reference color _{(a i, b i, L} i) by substituting the distance D _t-i and each, Calculate coefficients g11 _(t) , g22 _(t) , g33 _(t) , g12 _(t) , g13 _(t) and g23 _(t) of the target color ellipsoidal expression (basic color matching range). (Step S6).

  FIG. 4 shows the basic color matching range of the target color obtained in the processing of steps S1 to S6. The evaluation as to whether or not the paint color is the same as the target color is preferably performed at a plurality of light receiving angles in order to increase the reliability of the evaluation result. The figure shows that the basic color matching range of the target color is set for each light receiving angle. Here, the irradiation angle of the light source 41 with respect to the painted test piece 15 is 45 °, and the light receiving angle by the colorimeter 42 is 0 ° in the regular reflection direction, and the inclination angle from the regular reflection direction to the light source 41 side. Represents.

Next, in step S7, it is determined whether at least one of the plurality of color data (a _add , b _add , L _add ) obtained by the subjective evaluation experiment is outside the basic color matching range of the target color. When there is color data (a _add , b _add , L _add ) outside the basic color matching range of the target color, a convex hull (basic color of the target color) is obtained based on the color data (a _add , b _add , L _add ). A data set at the edge of the color matching range is generated (step S8). Then, the coefficients of the ellipsoidal expression are corrected by least-squares estimation so that the target color ellipsoid (basic color matching range) fits the convex hull (step S9, setting of evaluation color matching range). FIG. 6 shows an example in which the basic color matching range 1 is corrected to the evaluation color matching range 2 based on six color data (a _add1 , b _add1 , L _add1 ) to (a _add6 , b _add6 , L _add6 ). Show.

  As described above, according to the present embodiment, the basic color matching range 1 of the target color comparable to the color matching range of the reference color is set from the color matching range data of a plurality of known reference colors, without depending on visual evaluation. can do. Then, the basic color matching range 1 is corrected based on the subjective evaluation experiment data to obtain the color matching range 2 for evaluation. Therefore, even if there is a contrast, it is possible to obtain color-matching range data in which a person feels the same color, and the reliability of coating color evaluation increases.

Note that the color coordinate system is not limited to L ^* a ^* b ^* of CIE, and other coordinate systems such as RGB and XYZ may be adopted.

Further, the color coordinate system is not limited to three dimensions, and may be, for example, two dimensions a ^* b ^* .

1 basic color matching range of target color 2 color matching range for evaluation of target color 21 CPU (color matching range setting means, subjective evaluation data setting means, color matching range correction means)
26 storage device (storage means)

Claims (10)

In the color coordinate system, a method of setting a color matching range for evaluating whether the paint color is the same color as the target color,
In the color coordinate system, a step of statistically obtaining and setting a basic color matching range of the target color based on data on a color matching range of a plurality of reference colors,
Correcting a basic color matching range of the target color based on a plurality of color data on the color coordinate system that a person created based on a subjective evaluation experiment feels as the same color as the target color. A color matching range setting method for coating color evaluation, characterized in that: In claim 1,
The color coordinate system is a three-dimensional color space coordinate system,
The color matching range of each of the plurality of reference colors is defined by an ellipsoid,
Predicting each coefficient of an ellipsoidal expression relating to a specific reference color among the plurality of reference colors based on corresponding coefficients of the other plurality of reference colors, a specific reference for the coefficient relating to the other plurality of reference colors A prediction formula defined by a weighted average of the coefficients, taking into account the weight from the distance from the color and the tuning parameter,
The step of setting the basic color matching range of the target color includes:
Calculating a distance between the plurality of reference colors;
Predicting each of the coefficients of the plurality of reference colors by the prediction formula;
Determining a tuning parameter based on a predicted value and an actual value of the coefficient by the prediction formula,
Obtaining a calculation expression for obtaining each coefficient of the ellipsoidal expression of the target color by giving the determined tuning parameter to the prediction expression;
Obtaining an ellipsoidal expression that defines a basic color matching range of the target color by a weighted average of the coefficients for the plurality of preset reference colors using the above calculation formula. A color matching range setting method for color evaluation. In claim 2,
The step of correcting the basic color matching range of the target color includes:
Generating a convex hull including a plurality of color data based on the subjective evaluation experiment;
Correcting each coefficient of the ellipsoidal expression by least-squares estimation so that the ellipsoid that defines the basic color matching range of the target color fits the convex hull. Color matching range setting method. In any one of claims 1 to 3,
A method for setting a color matching range for evaluating a coating color, wherein the coating color is a coating color of a metallic coating. In claim 4,
A method for setting a color matching range for evaluating a coating color, wherein the metallic coating is applied to a vehicle body or exterior parts of a vehicle. In the color coordinate system, a device for setting a color matching range for evaluating whether the paint color is the same color as the target color,
Storage means for setting and storing a color matching range in the color coordinate system of each of the plurality of reference colors, a color matching range setting means for the target color, a subjective evaluation data setting means, and a color matching range correcting means; With
The target color matching range setting means statistically determines a basic color matching range of the target color based on data relating to a preset color matching range of a plurality of reference colors in the color coordinate system. Set,
The subjective evaluation data setting means sets, on the color coordinate system, a plurality of pieces of color data that a person created based on a subjective evaluation experiment feels as the same color as the target color,
The color matching range setting device for paint color evaluation, wherein the color matching range correcting means corrects a basic color matching range of the target color based on the plurality of color data. In claim 6,
The color coordinate system is a three-dimensional color space coordinate system,
The color matching range of each of the plurality of reference colors is defined by an ellipsoid,
Predicting each coefficient of an ellipsoidal expression relating to a specific reference color among the plurality of reference colors based on corresponding coefficients of the other plurality of reference colors, a specific reference for the coefficient relating to the other plurality of reference colors A prediction formula defined by a weighted average of the coefficients, taking into account the weight from the distance from the color and the tuning parameter,
The target color matching range setting means calculates a distance between the plurality of reference colors, predicts the coefficients of the plurality of reference colors by the prediction formula, and calculates a predicted value of the coefficients by the prediction formula. And a tuning parameter based on an actual value, and using a calculation formula obtained by giving the tuning parameter to the prediction formula, a weighted average of the coefficients relating to the plurality of preset reference colors is used to calculate the target color. A color matching range setting device for evaluating a paint color, wherein an ellipsoidal expression defining a basic color matching range is obtained. In claim 7,
The above color matching range correction means,
Generate a convex hull including a plurality of color data based on the subjective evaluation experiment, each of the ellipsoidal expressions by least square estimation so that the ellipsoid that defines the basic color matching range of the target color fits the convex hull A color matching range setting device for paint color evaluation, wherein a coefficient is corrected. In any one of claims 6 to 8,
The above-described paint color is a paint color of a metallic paint, and the color matching range setting device for paint color evaluation is characterized in that the paint color is a metallic paint paint color. In claim 9,
A color matching range setting device for evaluating a coating color, wherein the metallic coating is applied to a vehicle body or exterior parts of a vehicle.

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