Skin evaluation device, method, and program

Abstract

The present invention improves the accuracy of evaluating the texture of skin. A skin evaluation device according to an embodiment of the present invention evaluates the texture of a subject's skin, and comprises: a calculation unit that calculates the intensity of specularly reflected light specularly reflected on the surface of the skin due to the radiation of light, the uniformity of the specularly reflected light, and the intensity of subsurface scattered light emitted to the outside of the skin after being scattered inside the skin due to the radiation of the light; and an evaluation unit that evaluates the texture of the skin on the basis of the intensity of the specularly reflected light, the uniformity of the specularly reflected light, and the intensity of the subsurface scattered light.

Description

Skin evaluation device, method, and program

[0001] The present invention relates to a skin evaluation device, method, and program.

[0002] It has been known that the optical properties of an object (hereinafter also referred to as optical properties) create textures such as glossiness and transparency. It is also known that the optical properties of skin are involved in the texture of the skin.

[0003] Skin texture is an important factor that influences the perception of skin beauty, and therefore skin evaluation based on the optical properties of skin has been carried out (Patent Document 1).

[0004] JP 2016-94413 A

[0005] However, conventional methods only evaluate the degree of skin gloss based on the optical properties of the skin.

[0006] Therefore, an object of the present invention is to improve the accuracy of skin texture evaluation.

[0007] A skin evaluation device according to one embodiment of the present invention is a device for evaluating the texture of a subject's skin, and includes a calculation unit that calculates the intensity of specularly reflected light that is specularly reflected on the surface of the skin when irradiated with light, the uniformity of the specularly reflected light, and the intensity of subsurface scattered light that is scattered inside the skin when irradiated with light and then emitted to the outside of the skin, and an evaluation unit that evaluates the texture of the skin from the intensity of the specularly reflected light, the uniformity of the specularly reflected light, and the intensity of the subsurface scattered light.

[0008] According to the present invention, it is possible to improve the accuracy of skin texture evaluation.

[0009] FIG. 1 is an overall configuration diagram according to one embodiment of the present invention; FIG. 2 is a functional block diagram of a skin evaluation device according to one embodiment of the present invention; FIG. 3 is a diagram for explaining the uniformity of specular reflected light according to one embodiment of the present invention; FIG. 4 is a diagram for explaining the separation of surface reflection / subsurface scattering and the separation of specular reflection / diffuse reflection according to one embodiment of the present invention; FIG. 5 is a diagram for explaining a technique for separating surface reflection / subsurface scattering according to one embodiment of the present invention; FIG. 6 is a diagram for explaining the classification of skin texture according to one embodiment of the present invention; FIG. 7 is a diagram for explaining the relationship between optical characteristics of skin and skin condition according to one embodiment of the present invention; FIG. 8 is a diagram for explaining the relationship between optical characteristics of skin and age according to one embodiment of the present invention; FIG. 9 is a flowchart of skin evaluation processing according to one embodiment of the present invention; FIG. 10 is a block diagram showing an example of the hardware configuration of a skin evaluation device according to one embodiment of the present invention.

[0010] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described in detail below with reference to the accompanying drawings. It should be noted that the method for measuring light (for example, specularly reflected light and subsurface scattered light) is not limited to the measurement method described in this specification.

[0011] <Explanation of terms> - In this specification, "specular reflection" refers to the reflection of light that occurs on the surface of the skin where the angle of incidence and the angle of reflection are equal. - In this specification, "diffuse reflection" refers to the reflection of light that occurs on the surface of the skin, excluding specular reflection. - In this specification, "subsurface scattering" refers to light that passes through the surface of the skin, is scattered inside the skin, and then exits from the surface of the skin to the outside.

[0012] 1 is a diagram showing the overall configuration of an embodiment of the present invention. The skin evaluation system 1 includes a skin evaluation device 10, an imaging device 20, and a light source 30. Each of these will be described below.

[0013] The skin evaluation device 10 is a computer for evaluating skin texture. The skin evaluation device 10 evaluates skin texture based on the intensity of light specularly reflected from the surface of the skin upon irradiation from a light source 30 (hereinafter also referred to as specularly reflected light), the uniformity of the specularly reflected light, and the intensity of light emitted to the outside of the skin after being scattered within the skin upon irradiation from the light source 30 (hereinafter also referred to as subsurface scattered light). For example, the skin evaluation device 10 is a personal computer, a tablet terminal, a smartphone, etc.

[0014] For example, the skin evaluation device 10 may use images captured by the imaging device 20 (specifically, using skin shape information and skin color information) to calculate the intensity and uniformity of light specularly reflected from the skin surface upon irradiation from the light source 30 (i.e., specularly reflected light), the intensity of light diffusely reflected from the skin surface upon irradiation from the light source 30 (hereinafter also referred to as diffusely reflected light from the surface), and the intensity of light emitted to the outside of the skin after scattering within the skin upon irradiation from the light source 30 (i.e., subsurface scattered light). In this way, in one embodiment of the present invention, the physical characteristics of the skin (skin shape) and the optical characteristics of the skin (all light generated by the skin) can be evaluated from images captured using a single imaging device 20 and a single light source 30.

[0015] The imaging device 20 is a device for capturing an image of skin. Specifically, the imaging device 20 captures an image of the skin (for example, the entire face or a part of the face) whose texture is to be evaluated.

[0016] The skin evaluation device 10 can acquire shape information and color information indicating the three-dimensional shape of the skin (specifically, the X-coordinate, Y-coordinate, and Z-coordinate values ​​of each point, and the RGB values ​​of each point) from the image captured by the imaging device 20, or shape information and color information indicating the two-dimensional shape of the skin (specifically, the X-coordinate, Y-coordinate values ​​of each point, and the RGB values ​​of each point).

[0017] The light source 30 is an artificial light source that emits its own light.

[0018] In FIG. 1, the skin evaluation device 10, the image capture device 20, and the light source 30 are described as separate devices, but at least two of the skin evaluation device 10, the image capture device 20, and the light source 30 may be implemented in a single device.

[0019] <Functional Block> Fig. 2 is a functional block diagram of the skin evaluation device 10 according to one embodiment of the present invention. As shown in Fig. 2, the skin evaluation device 10 can include an image acquisition unit 101, a calculation unit 102, an evaluation unit 103, and a presentation unit 104. Furthermore, the skin evaluation device 10 can function as the image acquisition unit 101, the calculation unit 102, the evaluation unit 103, and the presentation unit 104 by executing a program.

[0020] The image acquisition unit 101 acquires an image of skin illuminated with light from the light source 30 from the imaging device 20. The image acquisition unit 101 acquires, from the image acquired from the imaging device 20, shape information and color information indicating the three-dimensional shape of the skin (specifically, the X coordinate, Y coordinate, and Z coordinate values ​​of each point, and the RGB values ​​of each point), or shape information and color information indicating the two-dimensional shape of the skin (specifically, the X coordinate, Y coordinate values ​​of each point, and the RGB values ​​of each point).

[0021] <<Intensity and Uniformity of Specularly Reflected Light, and Intensity of Subsurface Scattered Light>> The calculation unit 102 calculates the intensity of specularly reflected light that is specularly reflected from the surface of the skin in response to light irradiation, the uniformity (e.g., the degree of non-uniformity) of the specularly reflected light, and the intensity of subsurface scattered light that is emitted to the outside of the skin after being scattered inside the skin in response to light irradiation. Note that the light intensity (e.g., luminance) may be an absolute value or a relative value (e.g., the ratio of each to the whole (specularly reflected light, diffusely reflected light, and subsurface scattered light)). For example, the calculation unit 102 may calculate the intensity of specularly reflected light, the uniformity of specularly reflected light, and the intensity of subsurface scattered light using skin shape information and skin color information acquired by the image acquisition unit 101.

[0022] FIG. 3 is a diagram for explaining the uniformity of specularly reflected light according to one embodiment of the present invention.

[0023] in Figure 3 shows specularly reflected light when the skin is smooth. The angle of incidence of the incident light (the angle between the direction of propagation of the incident light and the normal to the boundary surface) and the angle of reflection of the reflected light (the angle between the direction of propagation of the reflected light and the normal to the boundary surface) are equal. In this case, the direction of propagation of the reflected light (stars in Figure 3) is uniform. In other words, the light specularly reflected from the surface of the skin when irradiated with light is uniform.

[0024] in Figure 3 shows specularly reflected light when the skin is uneven (for example, when the skin has pores, acne, fine wrinkles, texture, etc.). The angle of incidence of the incident light (the angle between the direction of propagation of the incident light and the normal to the boundary surface) and the angle of reflection of the reflected light (the angle between the direction of propagation of the reflected light and the normal to the boundary surface) are equal. In this case, the direction of propagation of the reflected light (stars in Figure 3) is non-uniform. In other words, the light specularly reflected from the surface of the skin due to irradiation with light is non-uniform.

[0025] In this way, the uniformity of the specularly reflected light is calculated based on the reflection direction of the specularly reflected light (the traveling direction of the reflected light in FIG. 3). Furthermore, the uniformity of the specularly reflected light may also be calculated based on the intensity of the specularly reflected light (the intensity of the reflected light in FIG. 3) (i.e., based on both the reflection direction and the intensity of the specularly reflected light). In FIG. 3, B1 indicates the non-uniformity based on the reflection direction of the specularly reflected light at the concave portions of the skin, B2 indicates the non-uniformity based on the reflection direction of the specularly reflected light at the convex portions of the skin, and B3 indicates the non-uniformity based on the intensity of the specularly reflected light.

[0026] Returning to Figure 2, for example, the calculation unit 102 may separate specularly reflected light, diffusely reflected light, and subsurface scattered light using the following method, and calculate the intensity of the specularly reflected light, the uniformity of the specularly reflected light, and the intensity of the subsurface scattered light. The following description will be divided into "Separation of surface reflection and subsurface scattering" and "Separation of specular reflection and diffuse reflection."

[0027] <<Separation of Surface Reflection and Subsurface Scattering>> The calculation unit 102 calculates the amount of light reflected from the surface of the skin (hereinafter also referred to as surface reflected light) and the amount of light emitted to the outside of the skin after scattering inside the skin (subsurface scattered light).

[0028] For example, in an image of skin onto which irradiated and non-irradiated pattern light is projected by a projector, the calculation unit 102 calculates the difference between the amount of light in the irradiated area and the amount of light in the non-irradiated area, and separates the light into a component of light reflected on the surface of the skin (surface reflected light) and a component of light scattered inside the skin and then emitted to the outside of the skin (subsurface scattered light).The calculation unit 102 calculates the amount of light of each component (i.e., the amount of surface reflected light and the amount of subsurface scattered light) based on the separation.

[0029] <<Separation of Specular Reflection and Diffuse Reflection>> The calculation unit 102 calculates the amount of light specularly reflected from the surface of the skin (specularly reflected light) and the amount of light diffusely reflected from the surface of the skin (diffusely reflected light from the surface).

[0030] For example, the calculation unit 102 calculates the difference between an unpolarized image captured using a polarizing filter and a polarized image captured without a polarizing filter, and separates the component of light specularly reflected from the skin surface (specularly reflected light) from the total amount of light from the skin (note that the total amount of light from the skin = specularly reflected light + other light (diffusely reflected light from the surface + subsurface scattered light), so the remaining light after separation includes both diffusely reflected light from the surface and subsurface scattered light). The calculation unit 102 can calculate the amount of diffusely reflected light from the surface by subtracting the subsurface scattered light from the remaining light after separation. Based on the separation, the calculation unit 102 calculates the amount of each component of light (i.e., the amount of specularly reflected light and the amount of diffusely reflected light from the surface).

[0031] Although the present specification describes a method using a polarizing filter, the present invention can also apply a separation method using a dichromatic reflection model or a specular reflection separation method using shape information.

[0032] Note that the light reflected from the skin surface in <<Separation of surface reflection and subsurface scattering>> consists of light specularly reflected from the skin surface and light diffusely reflected from the skin surface in <<Separation of specular reflection and diffuse reflection>>.

[0033] Here, with reference to FIGS. 4 and 5, the separation of surface reflection / subsurface scattering and the separation of specular reflection / diffuse reflection according to one embodiment of the present invention will be described.

[0034] FIG. 4 is a diagram for explaining the separation of surface reflection / subsurface scattering and the separation of specular reflection / diffuse reflection according to one embodiment of the present invention.

[0035] The imaging device 20 captures images of the subject's facial skin illuminated with light from the light source 30. Specifically, the imaging device 20 captures images for separating surface reflection from subsurface scattering and images for separating specular reflection from diffuse reflection. As described above, in one embodiment of the present invention, the images for separating surface reflection from subsurface scattering and images for separating specular reflection from diffuse reflection are captured using a single imaging device 20 and a single light source 30. The skin evaluation device 10 acquires information indicating the shape (three-dimensional shape or two-dimensional shape) and color of the skin from the images, and can calculate the amount of light specularly reflected from the skin surface upon irradiation from the light source 30 (specularly reflected light), the amount of light diffusely reflected from the skin surface upon irradiation from the light source 30 (diffusely reflected light from the surface), and the amount of light scattered within the skin upon irradiation from the light source 30 and then emitted to the outside of the skin (subsurface scattered light).

[0036] FIG. 5 is a diagram for explaining a method for separating surface reflection and subsurface scattering according to an embodiment of the present invention.

[0037] In step 101 (S101), the projector (light source 30) projects illuminated and non-illuminated patterned light onto the face of the subject. The imaging device 20 captures an image of the subject's face onto which the illuminated and non-illuminated patterned light is projected. In Fig. 5, the black areas (i.e., non-projected areas) are non-illuminated areas, and the other areas (i.e., projected areas) are illuminated areas.

[0038] In step 102 (S102), light from the projector (light source 30) is reflected from the surface of the skin, or passes through the surface of the skin and is scattered inside the skin before exiting the surface of the skin. Arrow 1 in Fig. 5 indicates light emitted by the projector (light source 30). Arrow 2 in Fig. 5 indicates light specularly reflected in the illuminated area. Arrow 3 in Fig. 5 indicates light diffusely reflected in the illuminated area. Arrow 4 in Fig. 5 indicates light emitted to the outside of the skin after scattering inside the skin in the illuminated and non-illuminated areas. Arrow 5 in Fig. 5 indicates light scattered inside the skin.

[0039] In step 103 (S103), the projector (light source 30) moves the illuminated / non-illuminated pattern light projected onto the face of the subject, changing the illuminated area in S101 to a non-illuminated area (i.e., the non-illuminated area becomes the illuminated area). Also, the imaging device 20 captures an image of the face of the subject onto which the moved illuminated / non-illuminated pattern light is projected.

[0040] The light components in the illuminated areas and the non-illuminated areas of the entire face are obtained by steps S101 and S103. The calculation unit 102 of the skin evaluation device 10 can obtain the light components reflected on the skin surface by subtracting the light components in the non-illuminated areas of steps S101 and S103 (i.e., areas where only light that has been scattered inside the skin and then emitted to the outside of the skin exists) from the light components in the illuminated areas of steps S101 and S103 (i.e., areas where both light reflected on the skin surface and light that has been scattered inside the skin and then emitted to the outside of the skin exist).

[0041] <<Skin Evaluation>> Returning to Fig. 2 , the evaluation unit 103 evaluates the skin texture based on the intensity of specularly reflected light that is specularly reflected from the surface of the skin in response to light irradiation, the uniformity of the specularly reflected light (e.g., the degree of non-uniformity), and the intensity of subsurface scattered light that is emitted to the outside of the skin after scattering within the skin in response to light irradiation, all of which are calculated by the calculation unit 102. Note that the evaluation unit 103 may also evaluate the skin texture based on the intensity of diffusely reflected light (i.e., based on the intensity of the specularly reflected light, the uniformity of the specularly reflected light, the intensity of the subsurface scattered light, and the intensity of the diffusely reflected light).

[0042] The evaluation unit 103 can evaluate the subject's skin texture by classifying it into one of a plurality of types. Specifically, the evaluation unit 103 can determine the type of the subject's skin texture based on the correspondence between the "intensity and uniformity of specular reflected light and the intensity of subsurface scattered light" and the "skin texture type."

[0043] The presentation unit 104 presents the results of the skin texture evaluation (for example, by displaying them on the skin evaluation device 10 or another device). For example, the presentation unit 104 presents beauty information according to the skin condition that is a factor in the skin texture (note that the skin condition that is a factor in the skin texture will be described later).

[0044] <<Classification of Skin Texture>> Classification of skin texture will be described below.

[0045] FIG. 6 is a diagram illustrating a skin texture classification according to an embodiment of the present invention. Spaces for each skin texture type (e.g., glossy skin, shiny skin, matte skin, dull skin, glittering skin, and transparent skin) are arranged within a space consisting of an axis representing the intensity of specularly reflected light, an axis representing the uniformity of specularly reflected light, and an axis representing the intensity of subsurface scattered light. The evaluation unit 103 can determine the skin texture type of the subject based on the correspondence between the "calculation of the intensity and uniformity of specularly reflected light and the intensity of subsurface scattered light" and the "skin texture type." Note that if the subject's skin texture falls into multiple types (i.e., multiple type spaces overlap), the evaluation unit 103 may determine the multiple types as the skin texture type of the subject, or may determine any one of the multiple types as the skin texture type of the subject.

[0046] Here, we will explain each type. For example, skin textures include glossy skin, shiny skin, matte skin, dull skin, shiny skin, and transparent skin. Below, we will explain the intensity of specular reflected light, the uniformity of specular reflected light, and the intensity of subsurface scattered light for each type. The specular reflected light intensity level (levels 1 to 10) indicates the degree of intensity of specular reflected light, with the higher the level value, the higher the intensity of specular reflected light. The specular reflected light uniformity level (levels 1 to 10) indicates the degree of uniformity of specular reflected light, with the higher the level value, the more uniform it is. The subsurface scattered light intensity level (levels 1 to 10) indicates the degree of intensity of subsurface scattered light, with the higher the level value, the higher the intensity of subsurface reflected light.

[0047] Glowing skin has a specular intensity level of 2-8, a specular uniformity level of 4-10, and a subsurface scattered light intensity level of 4-10.

[0048] Shiny skin has specular intensity levels between 5 and 9, specular uniformity levels between 0 and 5, and subsurface scattered light intensity levels between 1 and 7.

[0049] Matte skin has specular intensity levels of 0-5, specular uniformity levels of 1-9, and subsurface scattered light intensity levels of 2-10.

[0050] Dusky skin has specular intensity levels between 0 and 8, specular uniformity levels between 1 and 9, and subsurface scattered light intensity levels between 0 and 6.

[0051] Glaring skin has specular intensity levels between 5 and 10, specular uniformity levels between 0 and 4, and subsurface scattered light intensity levels between 0 and 7.

[0052] Clear skin has specular intensity levels of 0-8, specular uniformity levels of 4-10, and subsurface scattered light intensity levels of 5-10.

[0053] The optical property parameters used in this invention (i.e., the intensity of specularly reflected light, the uniformity of specularly reflected light, and the intensity of subsurface scattered light) and the skin texture types were discovered through the following experiments. [Skin Measurement] First, skin data from the subject was obtained. Specifically, the light on the skin was measured to obtain images showing the appearance of the skin, images showing specularly reflected light, images showing diffusely reflected light, and images showing subsurface scattered light. [Visual Assessment] Next, an observer observed and classified the images obtained by [Skin Measurement]. [Extraction of Optical Property Parameters Related to Skin Texture Evaluation] The results of [Skin Measurement] and [Visual Assessment] revealed that the intensity of specularly reflected light, the uniformity of specularly reflected light, and the intensity of subsurface reflected light affect skin texture.

[0054] <Estimation of Skin Conditions That Cause Skin Texture> In one embodiment of the present invention, the skin condition that causes skin texture can be estimated from at least one of the intensity of specularly reflected light, the uniformity of specularly reflected light, and the intensity of subsurface scattered light. The relationship between the optical properties of skin and the skin condition will be described in detail below with reference to FIG. 7.

[0055] 7 is a diagram illustrating the relationship between the optical properties of skin and skin condition according to one embodiment of the present invention. The intensity of specularly reflected light correlates with the hardness of the stratum corneum, sebum, and stratification of the stratum corneum. The uniformity of specularly reflected light correlates with the viscoelasticity of the skin, pores, acne, fine wrinkles, and texture of the skin. Subsurface scattered light correlates with melanin in the epidermis, transparency of the stratum corneum, moisture content of the stratum corneum, stratification of the stratum corneum, hemoglobin, and collagen in the dermis.

[0056] From the correlation in Figure 7, the evaluation unit 103 can estimate the skin condition, which is a factor in skin texture, from at least one of the intensity of specularly reflected light, the uniformity of specularly reflected light, and the intensity of subsurface scattered light.

[0057] For example, the evaluation unit 103 can estimate at least one of the hardness of the stratum corneum of the skin, the sebum of the skin, and the stratification of the stratum corneum of the skin from the intensity of the specularly reflected light.

[0058] For example, the evaluation unit 103 can estimate at least one of skin viscoelasticity, skin pores, skin acne, skin wrinkles, and skin texture from the uniformity of specularly reflected light.

[0059] For example, the evaluation unit 103 can estimate at least one of melanin in the epidermis of the skin, transparency of the stratum corneum of the skin, moisture content of the stratum corneum of the skin, stratification of the stratum corneum of the skin, hemoglobin in the skin, and collagen in the dermis of the skin from the intensity of the subsurface scattered light.

[0060] <Evaluation of Skin Texture According to Age> In one embodiment of the present invention, it is possible to evaluate whether the skin texture of a subject is appropriate for the subject's age. The relationship between the optical properties of skin and age will be described in detail below with reference to FIG. 8 .

[0061] 8 is a diagram illustrating the relationship between skin optical properties and age according to an embodiment of the present invention. As shown in FIG. 8, the intensity of specularly reflected light correlates with age, the uniformity of specularly reflected light correlates with age, and the intensity of subsurface scattered light correlates with age. Specifically, the intensity of specularly reflected light (left side of FIG. 8) increases with age. The uniformity (degree of non-uniformity) of specularly reflected light increases with age. The intensity of subsurface scattered light decreases with age.

[0062] From the correlation in FIG. 8, the evaluation unit 103 can evaluate whether the skin texture of the subject is appropriate for the subject's age.

[0063] <Method> FIG. 9 is a flowchart of a skin evaluation process according to an embodiment of the present invention.

[0064] In step 1 (S1), the image acquisition unit 101 acquires, from the image acquisition device 20, an image of skin illuminated with light from the light source 30. Next, the image acquisition unit 101 acquires, from the image acquired from the image acquisition device 20, shape information and color information indicating the three-dimensional shape of the skin (specifically, the X-coordinate, Y-coordinate, and Z-coordinate values ​​of each point, and the RGB values ​​of each point), or shape information and color information indicating the two-dimensional shape of the skin (specifically, the X-coordinate, Y-coordinate values ​​of each point, and the RGB values ​​of each point).

[0065] In step 2 (S2), the calculation unit 102 uses the skin shape information and skin color information acquired in S1 to calculate the intensity of specularly reflected light that is specularly reflected on the surface of the skin when light is irradiated, the uniformity (e.g., the degree of non-uniformity) of the specularly reflected light, and the intensity of subsurface scattered light that is scattered inside the skin when light is irradiated and then emitted outside the skin.

[0066] In step 3 (S3), the evaluation unit 103 evaluates the skin texture based on the intensity of specularly reflected light that is specularly reflected on the surface of the skin upon irradiation with light, the uniformity of the specularly reflected light, and the intensity of subsurface scattered light that is emitted to the outside of the skin after scattering within the skin upon irradiation with light, all calculated in S2. The evaluation unit 103 can evaluate the skin texture of the subject by classifying it into one of a plurality of types. Specifically, the evaluation unit 103 can determine the type of skin texture of the subject based on the correspondence between "calculation of the intensity and uniformity of specularly reflected light and the intensity of subsurface scattered light" and "skin texture type."

[0067] <Hardware Configuration> FIG. 10 is a block diagram showing an example of the hardware configuration of the skin evaluation device 10 according to one embodiment of the present invention.

[0068] The skin evaluation device 10 has a CPU (Central Processing Unit) 1001, a ROM (Read Only Memory) 1002, and a RAM (Random Access Memory) 1003. The CPU 1001, the ROM 1002, and the RAM 1003 form a so-called computer. The skin evaluation device 10 may also have an auxiliary storage device 1004, a display device 1005, an operation device 1006, an I / F (Interface) device 1007, and a drive device 1008. The hardware components of the skin evaluation device 10 are connected to each other via a bus B.

[0069] The CPU 1001 is a computing device that executes various programs installed in the auxiliary storage device 1004 .

[0070] The ROM 1002 is a non-volatile memory. The ROM 1002 functions as a main storage device that stores various programs, data, etc. required for the CPU 1001 to execute various programs installed in the auxiliary storage device 1004. Specifically, the ROM 1002 functions as a main storage device that stores boot programs such as a Basic Input / Output System (BIOS) and an Extensible Firmware Interface (EFI).

[0071] The RAM 1003 is a volatile memory such as a dynamic random access memory (DRAM) or a static random access memory (SRAM). The RAM 1003 functions as a main storage device that provides a working area in which various programs installed in the auxiliary storage device 1004 are expanded when the CPU 1001 executes them.

[0072] The auxiliary storage device 1004 is an auxiliary storage device that stores various programs and information used when the various programs are executed.

[0073] The display device 1005 is a display device that displays the internal state of the skin evaluation device 10 and the like.

[0074] The operation device 1006 is an input device through which the administrator of the skin evaluation device 10 inputs various instructions to the skin evaluation device 10 .

[0075] The I / F device 1007 is a communication device that connects to a network and communicates with the skin evaluation device 10 .

[0076] The drive device 1008 is a device for loading a storage medium 1009. The storage medium 1009 here includes media that record information optically, electrically, or magnetically, such as a CD-ROM, a flexible disk, or a magneto-optical disk. The storage medium 1009 may also include semiconductor memory that records information electrically, such as an EPROM (Erasable Programmable Read Only Memory) or a flash memory.

[0077] The various programs to be installed in the auxiliary storage device 1004 are installed, for example, by setting the distributed storage medium 1009 in the drive device 1008 and reading the various programs recorded on the storage medium 1009 by the drive device 1008. Alternatively, the various programs to be installed in the auxiliary storage device 1004 may be installed by being downloaded from a network via the I / F device 1007.

[0078] Although the examples of the present invention have been described in detail above, the present invention is not limited to the specific embodiments described above, and various modifications and changes are possible within the scope of the gist of the present invention as set forth in the claims.

[0079] This international application claims priority based on Japanese Patent Application No. 2021-164275, filed on October 5, 2021, the entire contents of which are hereby incorporated by reference into this international application.

[0080] REFERENCE SIGNS LIST 1 Skin evaluation system 10 Skin evaluation device 20 Imaging device 30 Light source 101 Image acquisition unit 102 Calculation unit 103 Evaluation unit 104 Presentation unit 1001 CPU 1002 ROM 1003 RAM 1004 Auxiliary storage device 1005 Display device 1006 Operation device 1007 I / F device 1008 Drive device 1009 Storage medium

Claims

1. An apparatus for evaluating the texture of a subject's skin, a calculation unit that calculates the intensity of specularly reflected light specularly reflected on the surface of the skin by light irradiation, the uniformity of the specularly reflected light, and the intensity of subsurface scattered light emitted to the outside of the skin after scattering inside the skin by the light irradiation; an evaluation unit that evaluates the texture of the skin from the intensity of the specularly reflected light, the uniformity of the specularly reflected light, and the intensity of the subsurface scattered light A skin evaluation apparatus comprising:

2. The skin evaluation apparatus according to claim 1, wherein the evaluation unit evaluates by classifying the texture of the skin into any one of a plurality of types.

3. The skin evaluation apparatus according to claim 2, wherein the plurality of types are glossy skin, shiny skin, matte skin, dull skin, shiny skin, and transparent skin.

4. The skin evaluation apparatus according to claim 1, wherein the evaluation unit estimates the state of the skin that is a factor in the texture of the skin from at least one of the intensity of the specularly reflected light, the uniformity of the specularly reflected light, and the intensity of the subsurface scattered light.

5. The state of the skin that is a factor in the texture of the skin is at least one of the hardness of the stratum corneum of the skin, the sebum of the skin, and the stratification of the stratum corneum of the skin, The skin evaluation apparatus according to claim 4, wherein the evaluation unit estimates at least one of the hardness of the stratum corneum of the skin, the sebum of the skin, and the stratification of the stratum corneum of the skin from the intensity of the specularly reflected light.

6. The state of the skin that is a factor in the texture of the skin is at least one of the viscoelasticity of the skin, the pores of the skin, the acne of the skin, the fine wrinkles of the skin, and the texture of the skin, The skin evaluation apparatus according to claim 4, wherein the evaluation unit estimates at least one of the viscoelasticity of the skin, the pores of the skin, the acne of the skin, the fine wrinkles of the skin, and the texture of the skin from the uniformity of the specularly reflected light.

7. The state of the skin that is a factor in the texture of the skin is at least one of melanin in the epidermis of the skin, the transparency of the stratum corneum of the skin, the water content of the stratum corneum of the skin, the stratification of the stratum corneum of the skin, hemoglobin in the skin, and collagen in the dermis of the skin. The evaluation unit estimates at least one of melanin in the epidermis of the skin, the transparency of the stratum corneum of the skin, the water content of the stratum corneum of the skin, the stratification of the stratum corneum of the skin, hemoglobin in the skin, and collagen in the dermis of the skin from the intensity of the subsurface scattered light. The skin evaluation device according to claim 4.

8. The skin evaluation device according to any one of claims 4 to 7, further comprising a presentation unit that presents beauty information according to the state of the skin that is a factor in the texture of the skin.

9. The evaluation unit evaluates whether the texture of the skin is according to the age of the subject. The skin evaluation device according to claim 1.

10. Further comprising an acquisition unit that acquires shape information and color information of the skin irradiated with light. The calculation unit calculates the intensity of the specular reflected light, the uniformity of the specular reflected light, and the intensity of the subsurface scattered light from the shape information and the color information. The skin evaluation device according to claim 1.

11. The shape information indicates the three-dimensional shape of the skin. The skin evaluation device according to claim 10.

12. A step of calculating the intensity of the specular reflected light specularly reflected on the surface of the skin by irradiation with light, the uniformity of the specular reflected light, and the intensity of the subsurface scattered light emitted to the outside of the skin after scattering inside the skin by the irradiation with light. A step of evaluating the texture of the skin from the intensity of the specular reflected light, the uniformity of the specular reflected light, and the intensity of the subsurface scattered light. A method including.

13. A computer A calculation unit that calculates the intensity of specular reflection light specularly reflected on the surface of the skin by light irradiation, the uniformity of the specular reflection light, and the intensity of subsurface scattering light emitted to the outside of the skin after scattering inside the skin by the light irradiation. An evaluation unit that evaluates the texture of the skin from the intensity of the specular reflection light, the uniformity of the specular reflection light, and the intensity of the subsurface scattering light. A program for causing it to function.