JP6947551B2 - Surface condition evaluation method - Google Patents

Description

The present invention relates to a surface condition evaluation method and a surface condition evaluation system for evaluating a condition related to a surface color.

At present, it is required at the site of drug development to evaluate the color of bare skin or skin to which an agent such as cosmetics is applied (hereinafter referred to as "cosmetic skin"). Known methods for evaluating such agents are described in, for example, Patent Document 1. The evaluation method described in Patent Document 1 is performed by acquiring the spectral reflection spectrum of the foundation. The spectral reflection spectrum of the foundation described in Patent Document 1 is dented due to a decrease in light reflectance in the range of 500 nm to 620 nm. Further, Patent Document 1 describes that when the above foundation was applied to the face of a model and sensory evaluation was performed, the result that the foundation looked healthier than that of the foundation of the comparative example was obtained.

Japanese Unexamined Patent Publication No. 10-17437

However, in recent years, in the field of drug development, evaluation of complicated factors such as "transparency" and "dullness" of bare skin or cosmetic skin has been desired. That is, when the skin is evaluated by the size of the dent appearing in the spectral reflection spectrum as in Patent Document 1, the skin color of a plurality of models for which the same evaluation value can be obtained may differ in the result of the sensory evaluation.
The present invention relates to a surface condition evaluation method and a surface condition evaluation system that evaluate factors related to skin dullness and are highly consistent with the results of sensory evaluation.

One aspect of the surface state evaluation method of the present invention is a surface state evaluation method for evaluating a state related to a surface color, which is a wavelength of light reflected on the surface and light corresponding to the wavelength. A parameter acquisition step for acquiring an evaluation parameter indicating the relationship between the reflectance of A second feature amount showing a tendency of change of the evaluation parameter appearing in two ranges and a feature amount acquisition step for acquiring the feature amount are included, and the relationship between the first feature amount and the second feature amount indicates that the surface is Evaluate the state of color.

It is possible to provide a surface condition evaluation method and a surface condition evaluation system that are highly consistent with the results of sensory evaluation by evaluating factors related to skin dullness.

It is a flowchart which showed each step of the evaluation method of the skin condition of one Embodiment of this invention. It is a figure for demonstrating the evaluation parameter acquisition process shown in step S101 of FIG. It is a figure for demonstrating the component of light included in the evaluation curve shown in FIG. 2 (b) and FIG. 2 (c). It is a figure for demonstrating the method of extracting the 1st feature amount and the 2nd feature amount of one Embodiment of this invention. It is a figure which shows the appearance of the state evaluation system of the surface of one Embodiment of this invention. It is a block diagram for demonstrating the control part which is the evaluation part inside the personal computer shown in FIG. It is a figure for demonstrating the effect obtained by one Embodiment of this invention. It is another figure for demonstrating the effect obtained by one Embodiment of this invention.

Hereinafter, an embodiment of the present invention will be described with reference to the drawings. In all drawings, similar components are designated by the same reference numerals, and duplicate description will be omitted as appropriate.
[Surface condition evaluation method]
The surface state evaluation method of the present embodiment is a surface state evaluation method for evaluating the state related to the color of the surface, and is a wavelength of light reflected on the surface and the reflectance of light corresponding to this wavelength. A parameter acquisition process for acquiring evaluation parameters indicating the relationship between The state related to the color of the surface is evaluated by the relationship between the second feature amount showing the tendency of change, the feature amount acquisition process for acquiring the first feature amount, and the second feature amount.
Here, the "face" may be the surface of the skin (skin) of a living body, a replica imitating the skin, or the surface of a doll such as a mannequin or a figure. When the surface is the surface of human skin, this surface may be bare skin without the agent applied, or may be cosmetic skin with the agent applied.

Here, the "agent" may be anything as long as it is applied to human skin and remains on the skin and affects the appearance of the skin. Examples of such agents include solid and liquid foundation creams and sunscreens (sunscreens).
However, the present embodiment is not limited to such a configuration. For example, the agent in the present embodiment is not limited to the one applied to the entire face such as foundation, and may be a cosmetic agent used for point makeup such as cheek, eye shadow and concealer. Further, it may be an agent used together with a foundation such as a makeup base.

The above-mentioned "state related to the color of the surface" includes not only the pigment (color) of the surface but also the appearance factor depending on the shape (unevenness, etc.) of the surface of the surface, the amount of water and the amount of oil and fat. The "wavelength of light reflected on the surface and the reflectance of light corresponding to this wavelength" can be detected, for example, by measuring the spectral spectrum of the reflected light reflected on the surface.
The "first and second ranges of wavelengths of light" refer to each of the wavelength ranges in which the wavelength measurement range is divided into at least two wavelength ranges. In the present embodiment, the first range is defined as a "short wavelength region" in which the wavelength is relatively short in the measurement range, and the second range is defined as a "medium / long wavelength region" in which the wavelength is longer than the short wavelength region.
The "evaluation parameter" is a factor indicating the relationship between the wavelength of light and the reflectance of light corresponding to this wavelength. In the present embodiment, for example, when light having a wavelength of 500 nm is reflected on a 30% plane, a pair of 500 nm and 30% is used as one of the evaluation parameter data. The "tendency of change in evaluation parameters" refers to a method of change such as the amount of change in reflectance and the ratio of change between a plurality of consecutive such data.

FIG. 1 is a flowchart showing each step of the above-mentioned coating state evaluation method. As shown in FIG. 1, the coating state evaluation method of the present embodiment includes an evaluation parameter acquisition step (step S101), a first feature amount acquisition step (step S102), and a second feature amount acquisition step (step S103). There is. In the present embodiment, it is assumed that the surface that reflects light is the surface of a living body, particularly the skin surface of a human face. Hereinafter, each of the above steps shown in FIG. 1 will be described in order.

(Parameter acquisition process)
2 (a), 2 (b) and 2 (c) are diagrams for explaining the evaluation parameter acquisition process shown in step S101 of FIG. FIG. 2A is a diagram showing a small region A used for measuring reflectance. The small area A is preferably a part of the subject's face on which the reflected light is measured and has few wrinkles and stains that can disturb the observation of the application state of the agent. Further, when paying particular attention to the dullness of the skin, it is preferable to set the portion where the dullness can be observed as a whole as the small area A.
2 (b) and 2 (c) are both diagrams showing the evaluation parameters of the present embodiment, and are reflected on the skin surface in order to intuitively show the tendency of the change in the relationship between the reflectance and the wavelength. The relationship between the wavelength of the light to be produced and the reflectance of the light corresponding to this wavelength is shown as a curve. In the present embodiment, the curves shown in FIGS. 2 (a) and 2 (c) will be hereinafter referred to as “evaluation curves”.

2 (b) and 2 (c) are for different subjects. The vertical axis of FIGS. 2 (b) and 2 (c) is the reflectance of light. The horizontal axis is the wavelength of light (nm ^-1 ), the vertical axis is the spectral reflectance, and the horizontal axis is the reflectance for each wavelength component of light. The reflectance may be any of surface reflection, internal reflection and total light reflection. In FIGS. 2 (a) and 2 (b), the wavelength on the horizontal axis is divided into a short wavelength region in the range of about 430 nm or more and less than 510 nm and a medium-long wave region in the range of about 510 nm or more and 710 or less. In the present embodiment, the first information and the second information are defined as the reflectance of light having a wavelength in the medium-long wave region in a predetermined range of 510 nm or more and 710 or less.
The present embodiment is not limited to scanning all continuous wavelengths in a predetermined range for measuring reflectance, and may discontinuously measure reflected light of a plurality of wavelengths.

In FIGS. 2 (b) and 2 (c), the wavy line is an evaluation curve when the small region A is bare skin. The solid line is an evaluation curve when the powder foundation (PFD) is applied to the small area A. The powder foundation is a solid foundation containing powder, and contains a pigment, an ultraviolet scattering agent, a moisturizer, and the like. Examples of the powder include hydroxyapatite, acrylate crosspolymer, silica and (vinyldimethicone / methicone silsesquioxane) crosspolymer. Examples of the pigment include talc, mica, titanium oxide, synthetic phlogopite, zinc oxide and oxidation (Li / K / titanium), and among them, titanium oxide and synthetic phlogopite also function as an ultraviolet scattering agent. Examples of the moisturizer and the rough skin preventive agent include panthenol, hydroxyproline, polyquaternium-61, sodium hyaluronate and the like.

The evaluation curve showing the reflectance measured in the small area A of the subject (hereinafter referred to as “subject α”) shown in FIG. 2 (b) shows that the powder foundation is formed even when the small area A is in the state of bare skin. Even in the coated state, it rises with a relatively gentle slope in the short wavelength region, the slope becomes gentle between 530 nm and 630 nm, and then rises with a steep angle. Therefore, the evaluation curve has a portion (curve portion) C that slightly curves downward at the portion where the inclination changes. Such a reflectance characteristic is also the same in the reflectance measured in the small region A of the subject (hereinafter referred to as “subject β”) shown in FIG. 2 (c).

However, in the specific shape of the evaluation curve, the color of the small region A is different between the subject α and the subject β. This point is caused by the difference in the color of the small region A between the subject α and the subject β. That is, the skin color of Japanese people is determined by the total amount or ratio of melanin, oxyhemoglobin and deoxyhemoglobin. The evaluation curve in the short wavelength region shows the amount of bluish component of the skin, and the evaluation curve in the medium and long wavelength region shows the amount of reddish component of the skin.
Comparing the evaluation curve of FIG. 2 (b) and the evaluation curve of FIG. 2 (c), the evaluation curve shown in FIG. 2 (b) is larger than the evaluation curve shown in FIG. 2 (c) in the curved portion. It can be seen that there is little change in shape before and after applying the powder foundation. This point indicates that subject α has less change in complexion impression due to application (makeup) of powder foundation than subject β. Such makeup is also called natural finish makeup and the like, and is one of the criteria for preferable makeup. The preferred criteria for makeup are not limited to the natural finish. For example, the target reflectance may be a preferable standard, or makeup such as stage makeup in which facial features can be clearly seen from a relatively long distance may be a preferable standard.

FIG. 3 is a diagram for explaining the components of light included in the evaluation curves shown in FIGS. 2 (b) and 2 (c). The vertical axis of FIG. 3 shows the reflectance of light, and the horizontal axis shows the wavelength of light corresponding to the reflectance shown on the vertical axis. Japanese skin color consists of three components: oxyhemoglobin, deoxyhemoglobin and melanin. Therefore, as shown in FIG. 3, the evaluation curve includes a component showing oxyhemoglobin (shown by a solid line in FIG. 3), a component showing deoxyhemoglobin (shown by a wavy line in FIG. 3), and deoxyhemoglobin (shown by a wavy line in FIG. 3). A component indicating (shown by a wavy line in 3) is included. Among such components, the component of oxyhemoglobin relates to red, and the component of deoxyhemoglobin relates to a dull red color rather than the red color indicated by oxyhemoglobin. Melanin also relates to the black component.

In the wavelength range of about 430 nm or more and 480 nm or less in FIG. 3, the component of oxyhemoglobin and the component of deoxyhemoglobin take relatively close values, and the component of melanin in the reflected light is also relatively large. If the melanin component is relatively high in this wavelength range, the skin color will appear yellowish. In addition, when the melanin component is relatively low, the skin color becomes purplish. The skin color that looks yellowish is evaluated as "having a yellow dullness" in the present embodiment.
Further, in the range where the wavelength is about 530 nm or more and 600 nm or less in FIG. 3, the reflectances of oxyhemoglobin and deoxyhemoglobin are reduced. Therefore, the size of the depression in the curved portion C shown in FIGS. 2 (b) and 2 (c) reflects the total amount of oxyhemoglobin and deoxyhemoglobin. When the total amount of oxyhemoglobin and deoxyhemoglobin is relatively large, the skin color appears bright red, and when it is relatively small, the skin color appears pale. The skin color that looks pale is evaluated as "having a pale dullness" in the present embodiment. Further, in the wavelength range of 600 nm or more, light reaches a portion deeper than the surface of the skin, and the evaluation curve is absorbed or reflected by a blood vessel or the like located deeper than the surface of the skin.

(First feature amount acquisition process)
As shown in steps S102 and S103 of FIG. 1, the feature amount acquisition step of the present embodiment includes a first feature amount extraction step (step S102) and a second feature amount extraction step (step S103). I'm out. The first feature amount of the present embodiment is obtained from the slope of the evaluation curve in the short wavelength region (first range of wavelength). The second feature is obtained from the degree of bending of the evaluation curve in the medium / long wavelength region (first range of wavelength). In the present embodiment, the degree of bending of the evaluation curve is defined as the degree of bending of the curve portion C shown in FIGS. 2 (b) and 2 (c).
In the present embodiment, the color including the dullness of the skin of the subject is evaluated by the combination of the first feature amount and the second feature amount.

FIG. 4 is a diagram for explaining a method of extracting the first feature amount and the second feature amount, in which the vertical axis represents the reflectance of light and the horizontal axis corresponds to the reflectance shown on the vertical axis. It shows the wavelength of light.
(First feature amount)
The first feature amount is obtained from the slope of the evaluation curve E in the short wavelength region. In the present embodiment, for example, the evaluation curve E in the short wavelength region is approximated to a straight line, and the slope of the straight line obtained by the approximation is used as the first feature quantity. The straight line approximation may be performed over the entire short wavelength region, or may be performed within a wavelength range in which the linearity of the evaluation curve E is within a predetermined allowable range. Further, the "slope" referred to in the present embodiment may be geometrically obtained from the evaluation curve E, or may be obtained by calculating the change in the reflected light data corresponding to the corresponding wavelength range. May be good.
When the surface is the skin surface of a living body, the first feature amount of the present embodiment serves as an index regarding the amount of at least one of melanin pigment, oxyhemoglobin, and deoxyhemoglobin pigment. The quantity referred to here is not limited to an absolute quantity, and may be represented by a relative value, a ratio, or the like. In the present embodiment, it is evaluated that the larger the first feature amount, the larger the ratio of oxyhemoglobin to deoxyhemoglobin in the skin color of the subject.

(Second feature)
The second feature amount is obtained, for example, as the area of the region R surrounded by the dent of the curved portion C shown in FIG. 4 and the straight line connecting both ends of the dent. Specifically, assuming that the function showing the evaluation curve E is f (λ), the quadratic derivative f''(λ) of the function f (λ) is obtained, and f in the medium and long wavelength regions, respectively. '' (λ) is the minimum wavelength λ1 (nm) and wavelength λ2 (nm) are obtained, and the reflectances at this time are connected by a straight line S. Then, the area of the portion between f (λ) and the straight line S (the portion shown by shading in FIG. 4) is obtained. The quadratic derivative f''(λ) of f (λ) can also be approximately obtained when the measured values of f (λ) are discrete.
Such a second feature amount serves as an index regarding the amount of pigment of at least oxyhemoglobin or deoxyhemoglobin. The quantity referred to here is not limited to an absolute quantity, and may be represented by a relative value, a ratio, or the like. In the present embodiment, it is evaluated that the larger the second feature amount, the larger the total amount of hemoglobin (oxyhemoglobin + deoxyhemoglobin).
In this embodiment, as described above, in addition to the reddish flesh color (healthy color) caused by the total amount of hemoglobin, the amounts of oxyhemoglobin and deoxyhemoglobin (the ratio is included in the relative amounts) and melanin. The dullness of the skin color can be evaluated using the color of. Therefore, this embodiment can evaluate the complexion with higher accuracy than the invention described in Patent Document 1, which evaluates the complexion based on the total amount of hemoglobin.

Further, in the surface state evaluation method of the present embodiment, the evaluation parameters of the target surface (hereinafter, referred to as “target evaluation parameters”) can be acquired.
Here, the target evaluation parameter refers to, for example, a set of data that forms a favorable evaluation curve for the skin of the subject. The target evaluation parameter may be a set of data forming an arbitrary evaluation curve, instead of the data obtained by measuring the reflected light on the surface of the living body. Such data includes, for example, an evaluation parameter created by arbitrarily processing the slope of a curve drawn by an evaluation parameter obtained by measuring the reflected light on the surface of a living body and the size of a depression in the curve portion C. There may be. Further, the target evaluation parameter may be obtained by measurement or calculation from a target person, a three-dimensional object, an image, or the like.

Further, in the present embodiment, in the parameter acquisition step, the wavelength of the light reflected on the surface and the reflectance of the light corresponding to this wavelength are measured to acquire the evaluation parameter, and the first evaluation parameter is obtained. The difference between the relationship between the feature amount and the second feature amount and the relationship between the first feature amount and the second feature amount of the target evaluation parameter may be shown. The difference may be shown as a simple numerical value (for example, first feature amount xxx, second feature amount yyy), or may be shown as a vector centered on the first feature amount and the second feature amount.
By comparing the evaluation parameters with the target evaluation parameters, the present embodiment recognizes the difference between the target person, the modeled object, the image, etc. and the subject's skin, and in order to approach the target skin, etc., the subject's skin, etc. It becomes possible to obtain suggestions such as adding a melanin pigment to the color or adding redness.

(Agent selection process)
Further, in the surface condition evaluation method of the present embodiment, an agent selection step of selecting an agent in which the difference between the evaluation parameter after application and the target evaluation parameter becomes smaller than the difference before application by applying to the surface. May be further included. Here, the agent is, for example, a foundation, a makeup base, a dolan, a make-up agent, etc., which can change the color and texture of the skin. Such a process is realized, for example, by pairing an evaluation parameter and a target evaluation parameter, and previously associating an agent effective for bringing the evaluation parameter closer to the target evaluation parameter with the pair of the evaluation parameter and the target evaluation parameter. can. Further, in the present embodiment, instead of the evaluation parameter, the first feature amount and the second feature amount obtained from the evaluation parameter and the first feature amount and the second feature amount obtained from the target evaluation parameter are paired, and the pair is used. An agent effective for bringing the first feature amount and the second feature amount of the evaluation parameter closer to the first feature amount and the second feature amount of the target evaluation parameter may be associated in advance. Such a method can be realized by constructing a database that stores the evaluation parameters or the correspondence between the first feature amount and the second feature amount and the agent.

[Surface condition evaluation system]
Next, the surface condition evaluation system used in the surface condition evaluation method described above will be described. The process shown in the flowchart of FIG. 1 is performed by the surface condition evaluation system.
5 and 6 are diagrams for explaining the surface state evaluation system of the present embodiment. FIG. 5 is a diagram showing the appearance of a surface condition evaluation system, and FIG. 6 illustrates a control unit 60 which is an internal evaluation unit of the personal computer (Personal Computer, hereinafter “PC”) 3 shown in FIG. It is a block diagram for doing. The surface condition evaluation system of the present embodiment is a spectrum acquisition unit that acquires evaluation parameters indicating the relationship between the wavelength of light reflected on the surface of the skin and the light reflectance corresponding to this wavelength. Feature quantity to acquire the spectrum measuring instrument 1, the first feature quantity showing the tendency of the evaluation parameter change appearing in the short wavelength region, and the second feature quantity showing the tendency of the evaluation parameter change appearing in the medium / long wavelength region. It includes an acquisition unit and a PC 3 that functions as an evaluation unit that evaluates a state related to a surface color according to the relationship between the first feature amount and the second feature amount. The PC 3 includes a user interface 32, a display unit 31, and a control unit 60 shown in FIG.

The spectroscopic spectrum measuring instrument 1 acquires incident light and reflected light in a small region A of bare skin or cosmetic skin. Then, the reflectance of the reflected light is input to the input interface 61 of the PC3 as the evaluation parameter P. The control unit 60 includes a first feature amount calculation unit 63 and a second feature amount calculation unit 65. The first feature amount calculation unit 63 calculates the first feature amount from the evaluation parameter P, and acquires the first feature amount obtained by the calculation. Further, the second feature amount calculation unit 65 calculates the second feature amount from the evaluation parameter P and acquires the second feature amount obtained by the calculation.
The control unit 60, for example, graphs the evaluation curve, the first feature amount, and the second feature amount as needed, and develops the image information of the graph in a memory (not shown). The image information of the expanded graph is output to the display unit 31. The display unit 31 is a concept including a display screen and a driver for displaying an image on the display screen. The control unit 60 evaluates the dullness and transparency of the skin condition of the subject according to the first feature amount and the second feature amount without graphing the evaluation curve and the first feature amount and the second feature amount. May be displayed on the display unit 31 as a drawing or text.

[Verification of effect]
7 and 8 are diagrams for explaining the effect obtained by the surface condition evaluation method and the surface condition evaluation system of the present embodiment. The vertical axis of FIGS. 7 and 8 shows the second feature amount, and the horizontal axis shows the first feature amount. In FIGS. 7 and 8, the smaller the value of the first feature amount, the greater the influence of melanin on the surface color, and the larger the value, the greater the influence of the pale component on the surface color. Further, the smaller the value of the second feature amount, the smaller the total amount of oxyhemoglobin and deoxyhemoglobin, and the larger the value of the second feature amount, the larger the total amount of oxyhemoglobin and deoxyhemoglobin. Each plot shown in FIGS. 7 and 8 shows the first feature amount and the second feature amount measured on the skin of different subjects.
Further, in the present embodiment, the complexion of each subject from which the plots shown in FIGS. It was classified into three categories: "good healthy colors". In FIGS. 7 and 8, the plots of the subjects evaluated as “yellowish dullness” are shown by diamonds, and the plots of the subjects evaluated as “pale finish” are shown by triangles. In addition, the plots of the subjects evaluated as "healthy color with good complexion" are shown in circles. In other words, the evaluation of "a healthy color with a good complexion" can be said to be a transparent skin color without dullness.

As shown in FIG. 7, each plot is displayed so as to fall within a predetermined range in any of "yellow dullness", "pale finish", and "healthy color with good complexion". That is, it can be seen that the skin having the same evaluation in the sensory evaluation has similar values in the first feature amount and the second feature amount, and has a correlation with the result of the sensory evaluation. When the same plots are grouped together, as shown in FIG. 8, group I of "yellowish dullness", group II of "pale finish", and group III of "healthy color with good complexion" can be formed.
From the above, the surface condition evaluation method and the surface condition evaluation system of the present embodiment acquire the first feature amount and the second feature amount by irradiating the bare skin or the cosmetic skin of the subject with light, and the first feature amount is obtained. The skin condition that correlates with the sensory evaluation can be evaluated from the feature amount and the second feature amount.
Further, in the present embodiment, since the skin color is evaluated in consideration of the first feature amount as well as the second feature amount, the color is further evaluated for the dullness parameter, and the dullness is evaluated with higher accuracy. Can be done. Such an embodiment can provide a surface condition evaluation method and a surface condition evaluation system that are highly consistent with the results of sensory evaluation by evaluating factors related to skin dullness.
Since the present embodiment in which the first feature amount and the second feature amount are obtained by measuring the reflectance of the skin is a non-invasive measurement method that does not touch the skin of the subject, it is performed without imposing a load on the subject. be able to. Further, in the present embodiment, even when the subject is wearing makeup, the first feature amount and the second feature amount can be obtained without removing the makeup, so that the subject can easily receive an evaluation of the skin condition. Can be done.
Further, the present embodiment is not limited to the configuration in which the spectroscopic spectrum measuring device 1 is used. For example, in the present embodiment, instead of the spectroscopic spectrum measuring device, a camera having no spectroscopic function may be provided with filters corresponding to the colors of, for example, R, G, and B to disperse the reflected light for each wavelength. In this way, it is possible to construct the surface state evaluation system of the present embodiment using a camera that is cheaper than the spectroscopic spectrum measuring instrument.

The above embodiments and examples include the following technical ideas.
<1> An evaluation method for evaluating the state of a surface, which evaluates a state related to the color of the surface, showing the relationship between the wavelength of light reflected on the surface and the reflectance of light corresponding to the wavelength. The parameter acquisition step of acquiring the parameters, the first feature amount showing the tendency of the change of the evaluation parameter appearing in the first range of the wavelength of light, and the change of the evaluation parameter appearing in the second range of the wavelength of light. The state of the surface, which includes a second feature amount showing a tendency and a feature amount acquisition step for acquiring, and evaluates a state related to the color of the surface based on the relationship between the first feature amount and the second feature amount. State evaluation method.
<2> The evaluation parameter is an evaluation curve which is a curve showing the relationship between the wavelength of light reflected on the surface and the reflectance of light corresponding to the wavelength, and the feature amount acquisition step is the first. One feature amount is obtained from the slope of the evaluation curve in the first range of the wavelength, and the second feature amount is obtained from the degree of bending of the evaluation curve in the second range of the wavelength. <1> Surface condition evaluation method.
<3> The surface is the skin surface of a living body, the first feature amount is an index relating to at least one of the pigments of melanin pigment, oxyhemoglobin and deoxyhemoglobin, and the second feature amount is A method for evaluating the state of the surface of <1> or <2>, which is an index relating to at least the amount of oxyhemoglobin or deoxyhemoglobin pigment.
<4> The surface state evaluation method according to any one of <1> to <3>, wherein the parameter acquisition step acquires a target evaluation parameter which is a target evaluation parameter.
<5> In the parameter acquisition step, the wavelength of the light reflected on the surface and the reflectance of the light corresponding to the wavelength are measured to acquire the evaluation parameter, and the first evaluation parameter of the evaluation parameter is obtained. The method for evaluating the state of the surface of <4>, which shows the difference between the relationship between the feature amount and the second feature amount and the relationship between the first feature amount and the second feature amount of the target evaluation parameter.
<6> The method for evaluating the state of the surface of <5>, further comprising an agent selection step of selecting an agent in which the difference after the coating is smaller than the difference before the coating by applying to the surface. ..
<7> An evaluation parameter showing the relationship between the wavelength of light reflected on the surface and the reflectance of light corresponding to the wavelength, which is a surface condition evaluation system that evaluates the color state of the surface. The parameter acquisition unit that acquires Includes a feature amount acquisition unit for acquiring a second feature amount indicating the above, and an evaluation unit for evaluating a state related to the color of the surface based on the relationship between the first feature amount and the second feature amount. Surface condition evaluation system.

1 ... Spectroscopic spectrum measuring device 31 ... Display unit 32 ... User interface 60 ... Control unit 61 ... Input interface 63 ... First feature amount generation unit 65 ... Second feature amount Generator

Claims (6)

It is a surface condition evaluation method that evaluates the condition related to the surface color.
A parameter acquisition step of acquiring an evaluation parameter indicating a relationship between the wavelength of light reflected on the surface and the reflectance of light corresponding to the wavelength.
The evaluation parameter is an evaluation curve which is a curve showing the relationship between the wavelength of light reflected on the surface and the reflectance of light corresponding to the wavelength, and is an evaluation curve of the evaluation curve in the first range of the wavelength. A feature amount acquisition step for acquiring a first feature amount acquired from the inclination and a second feature amount acquired from the degree of bending of the evaluation curve in the second range of the wavelength .
A method for evaluating the state of a surface, which evaluates the state related to the color of the surface based on the relationship between the first feature amount and the second feature amount. The surface is the skin surface of a living body, the first feature amount is an index relating to at least one of the pigments of melanin pigment, oxyhemoglobin and deoxyhemoglobin, and the second feature amount is at least oxyhemoglobin. The method for evaluating the state of a surface according to claim 1, which is an index relating to the amount of pigment of deoxyhemoglobin. The surface state evaluation method according to claim 1 or 2, wherein the parameter acquisition step acquires a target evaluation parameter which is a target evaluation parameter. In the parameter acquisition step, the wavelength of the light reflected on the surface and the reflectance of the light corresponding to the wavelength are measured to acquire the evaluation parameter, and the first feature amount of the evaluation parameter and the first feature amount of the evaluation parameter are obtained. The surface state evaluation method according to claim 3 , showing the difference between the relationship between the second feature amount and the relationship between the first feature amount and the second feature amount of the target evaluation parameter. The surface condition evaluation method according to claim 4 , further comprising an agent selection step of selecting an agent in which the difference after the coating is smaller than the difference before the coating by coating on the surface. A surface condition evaluation system that evaluates the color condition of a surface.
A parameter acquisition unit that acquires evaluation parameters indicating the relationship between the wavelength of light reflected on the surface and the reflectance of light corresponding to the wavelength.
The evaluation parameter is an evaluation curve which is a curve showing the relationship between the wavelength of light reflected on the surface and the reflectance of light corresponding to the wavelength, and is an evaluation curve of the evaluation curve in the first range of the wavelength. A feature amount acquisition unit for acquiring a first feature amount acquired from the inclination and a second feature amount acquired from the degree of bending of the evaluation curve in the second range of the wavelength .
An evaluation unit that evaluates a state related to the color of the surface based on the relationship between the first feature amount and the second feature amount.
Surface condition assessment system, including.

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