JP2016070847A - Method and device for evaluating gloss of cosmetic - Google Patents

Abstract

PROBLEM TO BE SOLVED: To objectively evaluate a gloss of cosmetics such as a lip stick.SOLUTION: In the method for evaluating a gloss of cosmetics, with a sensory evaluation score of a gloss of a coated surface on which cosmetics are coated defined as a dependent variable, through multivariable analysis in which skewness of an image (surface reflected light image) formed by a surface reflection light component on the coated surface on which cosmetics are coated and dispersion or standard deviation of the surface reflected light image are included in an independent variable, a sensory evaluation score of a gloss of a coated surface on which cosmetics as a gloss evaluation object are coated is calculated and a gloss of the cosmetics is evaluated based on the score.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a gloss evaluation method and an evaluation apparatus for cosmetics.

In cosmetics such as lipsticks, eye shadows, manicures and pedicures, the gloss recognized by the observer by applying it on the surface to be coated is one of the main evaluation items of the cosmetics.
In addition, since the gloss of the cosmetic applied to the surface to be applied may decrease over time, the gloss of the cosmetic applied to the surface to be applied is also objective from the viewpoint of grasping the characteristics of the cosmetic. It is desirable to be able to evaluate it automatically.

  Conventionally, as a method for evaluating the gloss perceived by a person with physical quantities, for example, for the gloss of an object having a pearl color such as a pearl, the image data of the object is acquired in a high luminance dynamic range with a wide luminance range, and the luminance A method of calculating the skewness of a value and using the skewness as an index of gloss is known (Patent Document 1).

  In addition, regarding an evaluation method of skin gloss, an image based on the surface reflection light component of the skin (hereinafter referred to as a surface reflection light image) is acquired, and the average of the pixel values represents the gloss strength, and the skewness and kurtosis are gloss. A method is known that expresses unevenness (smoothness of skin) (Patent Document 2).

WO2011 / 058823 JP2011-130808

  On the other hand, according to the knowledge of the present inventor, the sensation of gloss by the observer on the lip coated with lipstick does not necessarily correlate with the skewness of the surface reflected light image. Even in the reflected light image, there are cases in which the way of feeling gloss varies greatly.

  Therefore, an object of the present invention relates to a technique for objectively evaluating the gloss when a cosmetic material such as lipstick, eye shadow, manicure, pedicure or the like is applied to a surface to be coated.

  The present inventor, in the case of a surface reflection light image showing the same degree of distortion, as a result of a detailed study of the case where the way the viewer perceives gloss is greatly different, as a result of applying a cosmetic containing a specific component Therefore, it was found that it is difficult to use the skewness as a gloss evaluation index. Specifically, (i) gloss obtained by applying cosmetics to the surface to be coated includes oil-based gloss caused by the oil component contained in the cosmetics and pearl-based gloss caused by the pearl component. The observer feels the overall gloss due to these contributions. (Ii) Oil-based gloss is based on the degree of distortion, which is the third-order statistic of the surface reflected light image of the coated surface on which cosmetics are applied. It can be evaluated, but the correlation between pearl luster and skewness is low, and (iii) pearl luster is a secondary statistic of the surface reflected light image of the coated surface on which cosmetics are applied. Alternatively, the standard deviation can be evaluated as an index, and (iv) even in these cosmetics containing oil and pearl, at least the skewness of the surface reflected light image of the coated surface on which the cosmetic is applied and the dispersion or standard deviation are used as the index. Used to correlate with the gloss perceived by the observer It found that it is the valence, and conceived the present invention.

  That is, the present invention uses the sensory evaluation score of the gloss of the coated surface on which the cosmetic is applied as a dependent variable, the skewness of the surface reflected light image of the coated surface on which the cosmetic is applied, and the surface reflected light image. A multi-variate analysis including variance or standard deviation as an independent variable is used to calculate a sensory evaluation score for the gloss of the coated surface on which the cosmetic is applied, and to evaluate the gloss of the cosmetic based on the score. Provide an evaluation method.

Further, the present invention provides a surface reflected light image acquisition means for acquiring a surface reflected light image of a coated surface on which a cosmetic is applied,
A skewness calculating means for calculating the skewness of the surface reflected light image acquired by the surface reflected light image acquiring means;
Dispersion or standard deviation calculating means for calculating the dispersion or standard deviation of the surface reflected light image acquired by the surface reflected light image acquiring means;
The sensory evaluation score of the gloss of the coated surface on which the cosmetic is applied is a dependent variable, and the skewness of the surface reflected light image of the coated surface on which the cosmetic is applied and the variance or standard deviation of the reflected image are the independent variables. Storage means for storing a relational expression by multivariate analysis including,
Using the relational expression, at least the skewness calculated by the skewness calculation means and the dispersion or standard deviation calculated by the dispersion or standard deviation calculation means, the gloss sensory evaluation score of the coated surface on which the cosmetic is applied Sensory evaluation score calculating means for calculating
An apparatus for evaluating the gloss of a cosmetic material having

According to the present invention, the gloss felt by the observer is calculated from at least the surface reflected light image of the coated surface on which the cosmetic material such as lip cosmetics, nail cosmetics, and cosmetics around the eyes is applied. Can be estimated by multivariate analysis such as multiple regression analysis including skewness and variance or standard deviation as independent variables.
Therefore, the gloss of the cosmetic can be expressed by an objective evaluation index. In addition, this makes it possible to objectively represent a change in gloss over time when the cosmetic is applied to the surface to be coated.

FIG. 1 is a process diagram of an embodiment of a cosmetic gloss evaluation method. FIG. 2 is a block diagram of an embodiment of a cosmetic gloss evaluation apparatus. FIG. 3A is a normal image of a bare lip. FIG. 3B is a normal image of lips coated with lipstick containing a large amount of oil components. FIG. 3C is a normal image of a lip coated with a lipstick containing a large amount of a pearl component. FIG. 4A is a relationship diagram between an evaluation score of pearly luster and a RMS contrast by a beauty member. FIG. 4B is a relationship diagram between an oil-based gloss evaluation score and a degree of distortion by a beauty member. FIG. 5 is a graph showing the relationship between the overall gloss, the RMS contrast, and the skewness evaluated by a general female subject. FIG. 6 is a relationship diagram between an overall gloss evaluation score (estimated value) calculated using a multiple regression equation and an overall gloss evaluation score (subjective evaluation value) evaluated by a general female subject. . FIG. 7 is a graph showing the relationship between the overall gloss evaluation score (subjective evaluation value) evaluated by a general female subject and the skewness. FIG. 8 shows the prediction standard error between the gloss evaluation score estimated by the multiple regression analysis and the gloss evaluation score by the subject, and the gloss evaluation score estimated by the single regression analysis and the prediction of the gloss evaluation score by the subject. It is a figure which shows a standard error.

Hereinafter, the present invention will be described in detail with reference to the drawings.
FIG. 1 is a process diagram of an embodiment in which the gloss of lipstick is evaluated by the evaluation method of the present invention, and FIG. 2 is a block diagram of an evaluation apparatus that performs this evaluation method.

<< Cosmetics >>
Examples of cosmetics to be evaluated by the present invention include various cosmetics that require gloss on the coated surface. More specifically, it can be suitably used for evaluation of gloss of lip cosmetics such as lipsticks, glosses, lip liners, nail cosmetics such as manicures and pedicures, and cosmetics around the eyes such as eye shadows. This is because according to the present invention, an oil component that provides an oily luster or a pearl component that provides a pearly luster, or an oil component that provides an oily luster and a pearl component that provides a pearly luster are mixed. This is because the gloss of the cosmetic can be evaluated.

  Here, the oil-based gloss generated on the surface to which the cosmetic is applied is that the unevenness of the surface to be applied is flattened, and the brightness of a small area of the surface to which the light is applied is significantly higher than the surroundings. It can be said that

  For example, FIG. 3B is a normal image of a lip coated with a lipstick containing a large amount of an oil component, but the luminance of a small area exposed to light from the lips is higher than that of the normal image of a bare lip in FIG. 3A. Is significantly higher than

  Further, the pearly luster generated on the surface to which the cosmetic is applied is a state in which the luminance is increased over the entire surface to be applied. For example, FIG. 3C is a normal image of a lip coated with a lipstick containing a large amount of a pearl component, but a portion with high brightness is dispersed throughout the lip as compared to the normal image of a bare lip in FIG. 3A. .

  The surface to be coated in the case of evaluating the gloss of the cosmetic is not particularly limited, but a site assumed for each cosmetic is preferable, and examples thereof include lips, nails, and the vicinity of the eyelid.

  The lips are more curved than the nails and heels, and have vertical folds. Therefore, the influence of shadows is large, and the difference between oil-based luster and pearl-based luster tends to appear. Further, the lips are characterized in that the skin thickness is thinner than the epidermis, the surface irregularities of the lips are likely to change due to drying or the like, and the change in the appearance of the gloss is large. When the evaluation method or the evaluation apparatus of the present application is used for evaluating the gloss of the lip cosmetic, the shape of the lips and the change in the shape reflect on the evaluation of the gloss. Therefore, the evaluation method or evaluation apparatus of the present application can be suitably used as an evaluation method or evaluation apparatus for gloss of lip cosmetics.

  In cosmetics, oil components that give oily luster include oil agents having a high refractive index, preferably a refractive index (40 ° C.) of 1.45 or more, specifically hydrogenated polyisobutene, lauroyl glutamic acid. Examples thereof include oil agents having a high refractive index such as di (phytosteryl / octyldodecyl). Pearl components that give pearly luster include mica titanium, volatile inorganic pigments (Metashine series; manufactured by Nippon Sheet Glass Co., Ltd.), flaky glass (glass slake series, silky flake series; manufactured by Nippon Sheet Glass Co., Ltd.), etc. A pearl agent is mentioned. The content of these components is appropriately determined depending on the dosage form of the cosmetic and the glossiness desired.

  Taking lipstick as an example, in the case of oil-based lipstick that emphasizes the gloss of oil-based lipstick, the oil containing the high refractive index is 20% by mass or more, preferably 40% by mass or more, based on the total amount of lipstick. It is done. In the case of a pearl lipstick that emphasizes the pearl luster, those containing the pearl agent in an amount of 5% by mass or more, preferably 10% by mass or more based on the total amount of lipstick. Conversely, a lipstick that does not contain the oil agent or pearl agent having a high refractive index or that is contained in less than the above content can be cited as a mat-type lipstick with less gloss.

<< Image forming means >>
This evaluation apparatus 1 has an image forming means 2 and an arithmetic device 10 having an arithmetic function to be described later in order to acquire a surface reflected light image of a surface to be coated on which cosmetics are applied.
The image forming means 2 includes a speedlight provided as an illumination light source 3, a digital camera 4 for taking a color image, and polarizing plates 5 and 6 provided detachably on the front surfaces of the illumination light source 3 and the digital camera 4. ing. In the evaluation device 1, the surface reflected light image acquisition unit includes the image forming unit 2 and the image processing unit of the arithmetic device 10.

  The image forming unit 2 shoots the polarizing plate 5 on the front surface of the illumination light source 3 and the polarizing plate 6 on the front surface of the digital camera 4 so that the polarization directions of both are orthogonal to each other, so that the surface reflected light component of the object to be photographed is captured. An image (internal reflection light image) of the removed internal reflection light component is taken, and the polarizing plate 5 on the front surface of the illumination light source 3 and the polarizing plate 6 on the front surface of the digital camera 4 are set to have the same polarization direction. By photographing, a surface reflected light-enhanced image of the internal reflected light component and the surface reflected light component is taken. Further, the image forming means 2 can take a normal image by taking an image of an object to be photographed without using the polarizing plates 5 and 6.

  When evaluating the gloss of the lipstick, the image forming means 2 sets the face image with the lipstick applied to the lips as a subject to be photographed, and thereby the face image A (internal reflection light image) by the internal reflection light component, the internal reflection light component, A face image B (surface reflected light enhanced image) is formed by the surface reflected light component, and a normal face image C that does not use polarized light is formed as necessary.

<< Calculation device >>
<Formation of surface reflected light image>
The image processing means of the arithmetic device 10 forms a surface reflected light image by taking the difference between the surface reflected light enhanced image formed by the image forming means 2 and the internal reflected light image. In the case of evaluating the gloss of the lipstick described above, a face image by the surface reflected light component is formed by taking the difference between the face image B and the face image A.

  Further, the image processing means of the arithmetic unit 10 forms a mask image that masks a portion other than the portion (gloss evaluation portion) for which the gloss of the coated surface is to be evaluated, and multiplies the surface reflected light image and the mask image to thereby reflect the surface reflection. Gloss evaluation part image by light component is formed. The method for forming the mask is not particularly limited, such as a method using binarization or a method for manually forming the mask. In the case of evaluating the gloss of the lipstick, the G component of the RGB component is extracted from the face image by the surface reflected light component and binarized, whereby the pixel value of the lip region is 0 and the pixels of the other face region A mask image having a value of 1 is formed. This utilizes the fact that the lip region of the face image due to the internally reflected light component contains almost no G component of the RGB components constituting the color image. Then, the lip image by the surface reflected light component is formed by multiplying the mask image on the face image by the surface reflected light component.

  In addition, when the gloss evaluation part image by a surface reflected light component is already formed and preserve | saved as data, since the evaluation apparatus 1 receives the data via a communication means as a surface reflected light image acquisition means The data acquisition function may be provided, and the data acquisition function for capturing data via a storage medium may be provided.

<Calculation of skewness and variance or standard deviation>
As an image statistic, an average as a primary statistic, a variance as a secondary statistic, a standard deviation, a skewness as a tertiary statistic, and a kurtosis as a quadratic statistic are known. In the present application, the gloss of the cosmetic is evaluated using a score calculated by multivariate analysis including the third-order statistic and the second-order statistic as independent variables.

  In the following, an example using root-means-square (root mean square: RMS) contrast, which is a standard deviation of luminance, as a secondary statistic will be shown. The standard deviation is the square root of the variance, and the gloss can be evaluated by multivariate analysis even if the variance is used instead of the standard deviation (RMS contrast).

  In addition to the above-described means for forming the gloss evaluation portion image by the surface reflected light component, the arithmetic unit 10 also has a skewness calculating means for calculating the skewness of the image and an RMS contrast calculating means for calculating the RMS contrast of the image. Then, the skewness of the surface reflected light image of the gloss evaluation portion is calculated, and the RMS contrast is calculated.

Here, the skewness of the image is calculated by the following equation (1), represents the asymmetry of the luminance distribution of the pixels forming the image, and is effective as an index of gloss caused by the oil component. That is, when oil-based luster is felt on the surface to which the cosmetic is applied, the unevenness of the surface to be applied is flattened, and the brightness of the small area of the surface to which the light is applied is significantly higher than the surroundings. Become. Therefore, the luminance distribution of this image has asymmetry that there are a few pixels with very high luminance, and the degree of distortion is high.
In this way, the coated surface of the cosmetic material where the luster due to the oil component is felt strongly has a large degree of distortion.

式中、
Ｓk：歪度
Ｉ_ij：画像の画素（ｉ，ｊ）の輝度
Ｉ_m：平均輝度
Ｍ，Ｎ：画像サイズ（Ｍ×Ｎ）

Where
Sk: skewness I _ij : _{luminance of} image pixel (i, j) I _m : average luminance M, N: image size (M × N)

On the other hand, the RMS contrast of the image is calculated by the following equation (2), represents the spread of the luminance distribution of the pixels forming the image, and is effective as an index of gloss caused by the pearl component. That is, when a pearly luster is felt on the surface to which the cosmetic is applied, the luminance increases on the entire surface to be coated. For example, FIG. 3C is a normal image of lips coated with lipstick containing a large amount of pearl components. In the image of FIG. 3C, a portion with high luminance is dispersed throughout the lips as compared to the normal image of the lips of FIG. 3A. Therefore, the luminance distribution of this image has a broad peak width of the luminance distribution and a large RMS contrast.
Thus, the RMS contrast is increased on the coated surface of the cosmetic material where the gloss due to the pearl component is felt strongly.

式中、
Ｉ_ij：画像の画素（ｉ，ｊ）の輝度
Ｉ_m：平均輝度
Ｍ，Ｎ：画像サイズ（Ｍ×Ｎ）

Where
I _ij : Luminance of image pixel (i, j) I _m : Average luminance M, N: Image size (M × N)

  Note that the above-described image processing function performed by the image processing means of the arithmetic device 10 can be realized, for example, by installing commercially available image analysis software (for example, Adobe Photoshop) on a personal computer. The RMS contrast calculating means can be realized by mounting commercially available spreadsheet software (for example, Microsoft Excel).

<Multivariate analysis>
When a person feels gloss on the surface to which cosmetics are applied, it is considered that the person generally feels the intensity of gloss due to the contribution of both luster due to the pearl component and luster due to the oil component.

  Accordingly, in the gloss evaluation method of the present invention, the sensory evaluation score of the gloss of the surface to which the cosmetic is applied is set as a dependent variable in advance, and the distortion of the surface reflected light image of the surface to which the cosmetic is applied is determined. Multivariate analysis including degree and RMS contrast as independent variables is performed, and the relational expression is obtained.

As multivariate analysis, multiple regression analysis, PLS regression analysis, and the like can be performed. Further, the gloss of the coated surface may be evaluated on a plane map with the above-described skewness and RMS contrast as two axes. As an evaluation method on the planar map, there is a method using a classifier such as a linear classifier or a Bayes classifier.
From the viewpoint of ease of calculation, it is preferable to perform multiple regression analysis. For example, as an example using multiple regression analysis, gloss can be evaluated as follows.

That is, a plurality of types of cosmetics with different gloss impressions when applied to the surface to be coated are prepared in advance, and the gloss sensory evaluation score of the gloss evaluation part to which each cosmetic is applied is obtained. Forming a surface reflected light image of the gloss evaluation part coated with each cosmetic, calculating its skewness and RMS contrast, and using the sensory evaluation score of the gloss of the evaluation part coated with the cosmetic as a dependent variable, The following multiple regression equation is obtained by performing multiple regression analysis using the skewness of the surface reflected light image and the RMS contrast as independent variables.
[Gloss evaluation score] = a × [distortion] + b × [RMS contrast] + c
(Where a, b and c are coefficients)

  The arithmetic device 10 has storage means for storing this multiple regression equation. Note that the arithmetic unit 10 may be equipped with arithmetic means for performing this multiple regression analysis.

  In the present invention, the gloss sensory evaluation score is not the gloss sensory score for the surface reflected light image of the gloss evaluation part to which the cosmetic is applied, but the gloss sensory to the gloss evaluation part to which the cosmetic is actually applied. Assume an evaluation score. When there is a discrepancy between the impression of gloss received by the observer by actually observing the gloss evaluation part to which cosmetics are applied and the impression of gloss received by the observer by observing the image of the gloss evaluation part Because there is.

In addition, in order to evaluate the gloss of cosmetics, it is necessary to evaluate the cosmetics by applying the cosmetics to the surface to be applied. Take a lump of cosmetics in an image, calculate the distortion and RMS contrast. However, the gloss of cosmetics cannot be evaluated. For example, the gloss of lipstick is a texture that is felt when the lipstick is spread on the lips and a film is formed on the surface irregularities of the lips (lip shape and wrinkles on the lips). Therefore, in creating the above-described multiple regression equation, it is created based on the sensory evaluation score of a sufficient number of observers, or the lips to which the lipstick is applied are lips having a standard outer shape and standard surface irregularities. This is preferable because the superiority of the regression equation can be increased. In this case, the lips may be such human lips or doll lips imitating the surface irregularities (surface roughness) of the human lips. However, since it is desirable that the gloss of the lipstick when the general consumer applies the lipstick to the lips can be estimated finally, it is preferable to apply the lipstick to the human lips.
In addition, when evaluating the gloss of cosmetics other than the lipstick, the cosmetic is applied to the surface to be coated that is assumed for the cosmetic, and the sensory evaluation of the gloss is performed.

<< Method of evaluating gloss of cosmetics >>
In the gloss evaluation method of the present invention, in evaluating the gloss of each cosmetic material, first, the surface reflected light image of the coated surface on which the cosmetic material is applied is obtained by the above-described method, and the surface reflected light image is obtained. The skewness and RMS contrast are calculated. For example, when evaluating the gloss of the lipstick, the lipstick is applied to the lips, a surface reflected light image of the lips is acquired, and the skewness and the RMS contrast are calculated.

  Next, the relational expression stored in the storage means between the skewness and the RMS contrast by multivariate analysis and the sensory evaluation score of the gloss of the cosmetic is called, and the relational expression is used to calculate the degree of distortion and the RMS contrast. Get a sensory evaluation score for gloss of cosmetics.

  This gloss sensory evaluation score is useful as an objective index of the gloss of the surface to which the cosmetic is applied. Thereby, in the development of cosmetics, it becomes possible to predict the intensity of gloss felt by the user when the cosmetic is applied to the surface to be coated. In addition, when the composition of the cosmetic changes over time due to the inclusion of volatile components, it is possible to track the change over time in the gloss of the surface to which the cosmetic is applied.

Hereinafter, the present invention will be specifically described based on examples.
Example 1
(1) Preparation of lipstick Three kinds of lipsticks having different gloss impressions were prepared as follows according to the formulations shown in Tables 1 to 3.

A. Oil-based lipstick Components 1 to 9 shown in Table 1 were uniformly dissolved and mixed, components 10 to 14 were added, and after kneading, redissolved. Thereafter, the mixture was deaerated and poured into a mold, and after cooling and solidification, it was stored in a container to obtain a solid oil-based lipstick.

B. Pearl lipstick Components 1 to 8 shown in Table 2 were uniformly dissolved and mixed, components 9 to 13 were added, and redissolved after kneading. Ingredient 14 was added thereto and dispersed uniformly and mixed, degassed, poured into a mold, cooled and solidified, and stored in a container to obtain a solid pearl lipstick.

C. Matte lipstick Ingredients 1 to 6 shown in Table 3 were uniformly dissolved and mixed, ingredients 7 to 12 were added, and redissolved after kneading. Thereafter, it was deaerated and poured into a mold, and after cooling and solidification, it was stored in a container to obtain a solid mat-type lipstick.

(2) Gloss evaluation test (preliminary evaluation test by specialized panelists)
For the lips immediately after the application of each lipstick, a professional panelist (beauty member) evaluated the pearl luster and oil luster according to the subjectivity of the professional panelists, with a score of 1 (small gloss) to 10 (large gloss). .

  On the other hand, the surface reflected light image of the lips coated with lipstick was taken using the digital camera of the evaluation apparatus shown in FIG. In this case, as a light source for illumination, a digital camera is equipped with a speedlight with a diameter of 8 cm, the digital camera is installed at a distance of 60 cm from the subject's face, a front image of the subject's face is taken, and the skewness and RMS contrast of each image are obtained. Calculated.

  FIG. 4A shows the relationship between the pearl-based gloss evaluation score evaluated by the specialized panel and the RMS contrast, and FIG. 4B shows the relationship between the oil-based gloss evaluation score evaluated by the specialized panel and the skewness. From FIG. 4A, there is a correlation between the evaluation score of pearl luster and the RMS contrast by a specialized paneler (correlation coefficient: 0.693), and the pearl lipstick has a large numerical value of the pearl luster evaluation score. Since the contrast value is also large, it can be seen that RMS contrast is an evaluation index for pearl luster. Also, from FIG. 4B, there is a correlation between the evaluation score of the oil-based gloss and the degree of distortion by a specialized paneler (correlation coefficient: 0.866), and the oil-based lipstick has a large numerical value for the evaluation score of the oil-based gloss. Also, since the numerical value of the skewness is large, it can be seen that the skewness is an evaluation index of the glossiness of the oil system.

(Evaluation test by general women)
Eight general women became the subjects, and each of the three lipsticks prepared in (1) was applied. Immediately after application of each lipstick, 3 hours after application, and 5 hours after application, the overall gloss of the lips. The magnitude of gloss as a texture that the subject perceives sensuously, including both oil-based gloss and pearl-based gloss, was evaluated on a scale of 7 (score 1) to 7 (large gloss).

  FIG. 5 shows a relationship diagram of the overall gloss evaluation score, RMS contrast, and skewness evaluated by a general female subject. FIG. 5 shows that the overall gloss evaluation score increases when both the RMS contrast and the skewness are large.

  In the figure, the two broken lines and arrows indicate distortion when the viewpoint is moved from the group with the lower overall gloss evaluation score (lower broken line) to the higher group (upper broken line) as shown by the arrow. This indicates that both the degree and the RMS contrast are high.

  Therefore, a multiple regression analysis was obtained by performing multiple regression analysis using the overall gloss evaluation score evaluated by a general female subject as a dependent variable and the skewness and RMS contrast as independent variables. FIG. 6 shows a relationship between the overall gloss evaluation score (subjective evaluation value) evaluated by a general female subject and the gloss evaluation score (estimated value) calculated using a multiple regression equation. It can be seen that there is a strong correlation between the gloss evaluation score (estimated value) calculated using the multiple regression equation and the overall gloss evaluation score (subjective evaluation value) evaluated by a general female subject.

  On the other hand, FIG. 7 shows a relationship diagram between the overall gloss evaluation score and skewness evaluated by a general female subject. Since the correlation of the relationship diagram shown in FIG. 7 is weaker than that of the relationship diagram shown in FIG. 6, the overall gloss is better by multiple regression analysis using both skewness and RMS contrast. It can be seen that it can be estimated.

Example 2
Eight subjects (general females) applied each of three types of commercially available liquid lipsticks containing both an oil component and a pearl component to the lips. In the same manner as in Example 1, a surface reflected light image of the lips coated with lipsticks was obtained. Immediately after application, 3 hours after application, and 5 hours after application, the skewness and the RMS contrast were calculated from each image. In addition, as in Example 1, the subjects evaluated the overall gloss (subjective evaluation) immediately after application of the lips with lipstick applied, 3 hours after application, and 5 hours after application, in the same manner as in Example 1.
In the same manner as in Example 1, a multiple regression equation was obtained by performing multiple regression analysis with the gloss evaluation score by the subject as a dependent variable and the skewness and RMS contrast as independent variables.

A standard deviation (predicted standard deviation) of an error between the gloss evaluation score estimated using the multiple regression equation and the gloss evaluation score by the subject was obtained (Example 2).
Further, a prediction standard error between the gloss evaluation score estimated by the single regression analysis of the gloss evaluation score and the skewness by the test subject and the gloss evaluation score by the test subject was obtained (Comparative Example 2).

Further, the prediction standard error (Example 1) between the gloss evaluation score estimated by the multiple regression analysis in Example 1 and the gloss evaluation score by the subject (Example 1), the gloss evaluation score estimated by the single regression analysis, and the gloss by the subject. Prediction standard error with the evaluation score was obtained (Comparative Example 1).
These results are shown in FIG.

  From FIG. 8, gloss evaluation scores (Examples 1 and 2) estimated by multiple regression analysis using skewness and RMS contrast as independent variables are gloss evaluation scores (Examples 1 and 2) estimated by single regression analysis using skewness as variables ( It can be seen that the gloss can be estimated with higher accuracy than in Comparative Examples 1 and 2. It can also be seen that gloss can be accurately estimated regardless of the effect of the solid (Example 1, Comparative Example 1) and liquid (Example 2, Comparative Example 2) lipstick dosage forms.

DESCRIPTION OF SYMBOLS 1 Cosmetic gloss evaluation apparatus 2 Image forming means 3 Illumination light source 3
4 Digital camera 5, 6 Polarizing plate 10 Arithmetic unit

Claims (8)

  Using the sensory evaluation score of the gloss of the coated surface on which the cosmetic is applied as a dependent variable, the skewness of the image (hereinafter referred to as the surface reflected light image) due to the surface reflected light component of the coated surface on which the cosmetic is applied, and the The sensory evaluation score of the gloss of the coated surface on which the cosmetic is applied is calculated by multivariate analysis including the variance or standard deviation of the surface reflected light image as an independent variable, and the gloss of the cosmetic is evaluated based on the score. Evaluation method for gloss of cosmetics.   As a multivariate analysis, the sensory evaluation score of the gloss of the coated surface on which the cosmetic is applied is used as a dependent variable, and the skewness of the surface reflected light image of the coated surface on which the cosmetic is applied and the variance of the surface reflected light image Alternatively, the gloss evaluation method for cosmetics according to claim 1, wherein multiple regression analysis is performed with the standard deviation as an independent variable.   The method for evaluating the gloss of a cosmetic according to claim 1 or 2, wherein the cosmetic is a lip cosmetic, a nail cosmetic, or a cosmetic around the eyes.   For a plurality of cosmetics having different oil compositions and pearl compositions, the sensory evaluation score of gloss of the coated surface on which each cosmetic is coated is obtained and made a dependent variable, and the surface reflected light image of the coated surface The method for evaluating the glossiness of a cosmetic according to any one of claims 1 to 3, wherein the skewness and dispersion or standard deviation of the cosmetics are acquired and used as independent variables. Surface reflected light image acquisition means for acquiring a surface reflected light image of a surface to be coated with a cosmetic;
A skewness calculating means for calculating the skewness of the surface reflected light image acquired by the surface reflected light image acquiring means;
Dispersion or standard deviation calculating means for calculating the dispersion or standard deviation of the surface reflected light image acquired by the surface reflected light image acquiring means;
Using the sensory evaluation score of the gloss of the coated surface on which the cosmetic is applied as a dependent variable, the degree of distortion of the surface reflected light image on the coated surface on which the cosmetic is applied and the dispersion or standard deviation of the surface reflected light image are independent. Storage means for storing a relational expression by multivariate analysis included in a variable;
Using the relational expression, the gloss sensory evaluation score is calculated from the skewness calculated by the skewness calculating means and the dispersion or standard deviation calculated by the dispersion or standard deviation calculating means. Sensory evaluation score calculation means
An apparatus for evaluating the gloss of cosmetics.   6. The cosmetic gloss evaluation apparatus according to claim 5, wherein the relational expression based on multivariate analysis is a multiple regression equation.   The cosmetic gloss evaluation apparatus according to claim 5 or 6, wherein the cosmetic is a lip cosmetic, a nail cosmetic, or a cosmetic around the eyes.   For multiple cosmetics with different oil composition and pearl composition, the multiple regression equation is obtained from the surface reflected light image of the coated surface with the sensory evaluation score of the gloss of the coated surface coated with each cosmetic as a dependent variable The cosmetic gloss evaluation apparatus according to claim 6 or 7, which is obtained by a multiple regression analysis using the obtained skewness and the variance or standard deviation of the surface reflected light image as independent variables.

Images