JP2014087464A - Skin evaluation method and skin evaluation device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a skin evaluation method which can accurately evaluate the glossiness of a makeup skin correspondingly to subjective evaluation by human eyes.SOLUTION: The product of a gloss density ratio and a gloss area ratio, including information on ununiformity in a gloss area, is calculated as an evaluation value of skin glossiness, and the skin glossiness is evaluated on the basis of the evaluation value.

Description

  The present invention relates to a skin evaluation method for evaluating a change in makeup skin over time and a skin evaluation apparatus for implementing the method.

In recent years, with the increasing awareness of beauty, there is a great interest in the glossiness of various makeup skins such as “glossy”, “tekari” and “matte”.
In addition, in the skin to which cosmetics (foundation) is applied, the cosmetics are mixed with sebum and sweat produced from the skin over time. Is generated.

  Conventionally, as an evaluation method of glossiness, as described in Patent Document 1 and Patent Document 2, an entire face is photographed with a digital still camera or the like to generate a skin image, and the skin surface is generated from the generated skin image. The gloss area was extracted, the area ratio of the gloss area and the brightness of the gloss area were calculated, and the glossiness was evaluated based on these values.

JP 2011-212307 A Japanese Patent Laid-Open No. 2003-070749

However, if glossiness is evaluated using only the glossy area of the skin, it may not be compatible with visual observation, and it is simply high gloss and the area of the part is large. It does n’t mean that.
For example, FIG. 6 is a graph showing the correspondence between the average gloss value (average luminance value) and subjective (sensory) evaluation. The subjective evaluation is a 10-step evaluation by human eyes. The closer the evaluation value is to 1, the lower the glossiness is. The closer the evaluation value is to 10, the higher the glossiness is.
As shown in FIG. 6, when the average value of gloss was used as an index, there was a large difference in correspondence between the evaluation based on the conventional index and the subjective (sensory) evaluation. That is, with the conventional evaluation method, the skin cannot be evaluated well from the viewpoint of “tekari”.

  The present invention has been made to solve such conventional problems, and a skin evaluation method and a skin evaluation device capable of accurately evaluating the glossiness of makeup skin in accordance with subjective evaluation. The purpose is to provide.

  The skin evaluation method according to the present invention creates a total reflection image by photographing the skin by normal light image measurement, creates an internal scattering image by photographing the skin by polarization image measurement, and creates the created total reflection. A specular reflection image is created from the image and the internal scattering image, and the internal scattering image is separated into a skin groove portion and a skin hill portion on the skin surface to calculate the position information of the skin groove portion and the position information of the skin hill portion. An image showing the glossiness of the skin mound is created from the specular reflection image and the positional information of the skin mound, while creating a skin groove image that shows the glossiness of the skin groove portion from the mirror reflection image and the position information of the skin groove portion A skin mound image is created, and each gloss density value is calculated from the skin groove image and the skin mound image, and a gloss area ratio indicating an area ratio equal to or higher than a predetermined luminance is calculated from the skin mound image, and the skin groove portion Gloss Density Ratio from Gloss Density Value of Skin and Gloss Density Value of Dust Calculated, it calculates an evaluation value from the gloss area ratio and gloss concentration ratio, and evaluating the glossiness of the skin on the basis of the evaluation value.

  Further, the gloss density value may include any of an average value, a mode value, and a minimum value of luminance.

  The evaluation value is preferably a linear sum of the gloss area ratio and the gloss density ratio.

  Moreover, it is preferable to plot an evaluation value on coordinates having the gloss area ratio and the gloss density ratio as axes, and to evaluate the glossiness of the skin from a region including the plotted evaluation value.

  Further, the present invention creates a total reflection image by photographing the skin by normal light image measurement, creates an internal scattering image by photographing the skin by polarization image measurement, and creates the total reflection image and the internal scattering. A specular reflection image is created from the image, and the internal scattering image is separated into a skin groove part and a skin hill part on the skin surface, and the position information of the skin groove part and the skin hill part is calculated, and the specular reflection image is obtained. The skin mound is an image showing the glossiness of the skin mound from the specular reflection image and the position information of the skin mound. Create an image, calculate each gloss density value from the skin groove image and the skin mound image, obtain the area below the predetermined brightness from the skin groove image as the area of the skin groove area, The area of the skin groove area The ratio of the area of the hide hill area to the gloss area ratio is calculated, and the gloss density ratio is calculated from the gloss density value of the skin groove and the gloss density value of the hide hill, and is evaluated from the gloss area ratio and the gloss density ratio. A skin evaluation method is provided that calculates a value and evaluates the glossiness of the skin based on the evaluation value.

  The present invention also includes a normal light image creation unit that creates a total reflection image by photographing the skin by normal light image measurement, and a polarization image creation unit that creates an internal scattering image by photographing the skin by polarization image measurement. And a specular reflection image creation unit that creates a specular reflection image from the created total reflection image and internal scattering image, and the internal scattering image is separated into a skin groove part and a skin mound part, and the position of the skin groove part is separated. A position information calculation unit that calculates information and position information of the skin mound, and a skin groove image that is an image showing the glossiness of the skin groove part from the specular reflection image and the position information of the skin groove part, and a mirror reflection image Gloss density from the skin groove image and skin mound image, and the skin groove image and skin image, respectively Gloss density calculation part to calculate the value and gloss density of the skin groove image And a gloss density ratio calculation unit for calculating a gloss density ratio based on the gloss density value of the skin mound image, a gloss area ratio calculation unit for calculating a gloss area ratio indicating an area ratio equal to or higher than a predetermined luminance from the skin image, There is provided a skin evaluation apparatus characterized by having a gloss evaluation unit that calculates an evaluation value from a gloss area ratio and a gloss density ratio and evaluates the gloss of the skin based on the evaluation value.

  According to the present invention, since the makeup skin is evaluated by the unevenness of the gloss area such as the gloss density distribution and the gloss surface distribution, the gloss on the makeup skin can be accurately matched to the subjective evaluation by the human eye. It becomes possible to evaluate.

It is a block diagram which shows the structure of the skin evaluation apparatus which performs the skin evaluation method which concerns on Embodiment 1 of this invention. (A) is a skin groove mask image obtained from the internal scattering image, and (B) is a skin mound mask image obtained by inverting the skin groove mask image. It is a figure which shows the flow which creates a skin groove image and a skin mound image from a specular reflection image, a skin groove mask image, and a skin mask image in a skin groove image / skin image creation unit. 4 is a graph showing a relationship between an index according to Embodiment 1 and a subjective (sensory) evaluation value. It is a graph which shows the relationship between a glossiness parameter | index and the state of skin. It is a graph which shows the relationship between a conventional parameter | index and a subjective evaluation value.

Embodiments of the present invention will be described below with reference to the accompanying drawings.
Embodiment 1
In FIG. 1, the structure of the skin evaluation apparatus 1 which performs the skin evaluation method which concerns on Embodiment 1 of this invention is shown. The skin evaluation apparatus 1 evaluates the condition of the skin of the subject F using normal light image measurement and polarization image measurement, and a digital still camera that captures a total reflection image of the skin of the subject F by normal light image measurement. (DSC) 2, and a polarization filter 3 and a polarization measurement camera 4 that capture an internal scattering image of the skin of the face of the subject F by polarization image measurement. The specular reflection image creation unit 5 is connected to the DSC 2, and the specular reflection image creation unit 5 and the mask image creation unit 6 are connected to the polarization measurement camera 4. The specular reflection image creation unit 5 and the mask image creation unit 6 are connected to a skin groove image / skin image creation unit 7, respectively. The skin groove image / skin image creation unit 7 is connected to a gloss density calculation unit 8. The The gloss density calculation unit 8 is connected to a gloss density ratio calculation unit 9 and a gloss area ratio calculation unit 10, respectively. A gloss evaluation unit 11 is connected to the gloss density ratio calculation unit 9 and the gloss area ratio calculation unit 10. In addition, the specular reflection image creation unit 5, the mask image creation unit 6, the skin groove image / skin image creation unit 7, the gloss density calculation unit 8, the gloss density ratio calculation unit 9, the gloss area ratio calculation unit 10, and the gloss evaluation The unit 11 includes a CPU and an operation program for causing the CPU to perform various processes. However, the unit 11 may include a digital circuit.

  The DSC 2 is a general digital still camera that performs normal light image measurement, and the skin of the face of the subject F using normal light (light in which light waves having electric and magnetic fields oscillating in various directions are mixed). The image data is taken and this image data is stored in an internal memory (not shown). In addition, since the image photographed using normal light includes not only reflected light on the skin surface but also scattered light inside the skin, it is referred to as a “total reflection image” in this specification. And Total reflection image data stored in an internal memory (not shown) is output to the specular reflection image creation unit 5.

For example, the polarizing filter 3 is a unit in which polarizers for four directions of 0, 45, 90, and 135 degrees are arranged as one unit without a gap. The reflected light on the skin surface of the subject F does not change its polarization direction, whereas the scattered light inside the skin of the subject F changes its polarization direction due to scattering inside the skin, so that the polarizing filter 3 is polarized. By installing on the measurement camera 4 and photographing while blocking the reflected light on the skin surface of the subject F, it is possible to photograph an internally scattered image capturing only the scattered light inside the skin of the subject F.
The polarimetry camera 4 captures an internally scattered image based on the scattered light inside the skin of the face of the subject F by the operation of the operator, and stores the internally scattered image data in an internal memory (not shown). Internal scattered image data stored in an internal memory (not shown) is output to the specular reflection image creation unit 5 and the mask image creation unit 6, respectively. Note that the total reflection image and the internal scattering image are obtained on the condition that the same part of the skin of the face of the subject F is photographed.

  The specular reflection image creation unit 5 creates a specular reflection image from the total reflection image and the internally scattered image. The specular reflection image is an image based only on the reflected light from the skin surface of the subject F, and can be created by subtracting the component of the internal scattering image from the total reflection image. Specifically, specular reflection image data is created by subtracting the internal scattering image data output from the polarimetry camera 4 from the total reflection image data output from the DSC 2. The specular reflection image creation unit 5 performs alignment between the total reflection image and the internal scattering image, and then subtracts the corresponding internal scattering image component from the total reflection image. Various known methods such as pattern matching are used for the above-described alignment. The created specular reflection image data is output to the groove image / skin image creation unit 7.

The mask image creation unit 6 creates a skin groove mask image and a skin mound mask image based on the internal scattering image.
The skin surface is constituted by a skin groove portion that extends thinly as a groove and a skin mound portion surrounded by the skin groove portion. The skin mask image is a binary image for extracting only the skin groove portion with respect to the specular reflection image, and the skin mask image is for extracting only the skin portion with respect to the specular reflection image. This is a binary image.
For example, the mask image creation unit 6 performs edge extraction on the internally scattered image, and binarizes a portion surrounded by the edges and having a pixel luminance value lower than a predetermined value as a skin groove portion C. By doing so, the skin groove mask image shown in FIG. Then, when the skin groove mask image is created, the mask image creation unit 6 creates the skin mound mask image shown in FIG. 2B by inverting the image. The created skin mask image and skin mask image are output to the skin image / skin image creation unit 7 as skin mask image data and skin mask image data.
Note that the skin groove mask image data and the skin mound mask image data each play a role of position information indicating the position of the skin groove part and the skin mound part, and the mask image creation unit 6 functions as a position information calculation unit in the present invention. Plays.

In addition to the binarization based on the threshold value described above, the mask image creation unit 6 performs frequency analysis on the internal scattering image, and creates a skin groove mask image and a skin mound mask image by dividing the internal scattering image by a specific frequency. Alternatively, the skin groove mask image and the skin mound mask image may be created by separating the internally scattered image using a multivariate analysis method such as principal component analysis or independent component analysis.
Further, the mask image creation unit 6 uses a texture matching or learning method based on feature amount analysis such as SIFT (Scale-Invariant Feature Transform) or SURF (Speeded-Up Robust Features), and uses a skin mask image and a skin mask image. A skin mask image may be created.

The skin groove image / skin image creation unit 7 is based on the specular reflection image data output from the specular reflection image creation unit 5 and the skin groove mask image data and skin mask image data output from the mask image creation unit 6. Create skin groove image data and hide hill image data. The skin groove image is an image obtained by extracting only the skin groove portion from the specular reflection image, and the skin hill image is an image obtained by extracting only the skin hill portion from the specular reflection image. The skin groove image is an image showing the gloss of the skin groove part, and the skin mound image is an image showing the gloss of the skin part. Since the skin groove image is an image obtained by extracting the concave portions of the skin unevenness, not only the skin groove but also the pore portion is included.
As shown in the flowchart of FIG. 3, skin mirror image data is created by multiplying the specular reflection image data by the skin mask image data that is binary image data, and the skin mask image is also added to the specular reflection image data. The dune image data is created by multiplying the dune mask image data, which is binary image data created by inverting the data.
The created skin groove image data and skin mound image data are output to the gloss density calculation unit 8.

  The gloss density calculation unit 8 calculates the gloss density of the skin groove image and the gloss density of the skin image based on the skin image data and the skin image data output from the skin image / skin image creation unit 7, respectively. calculate. Specifically, the brightness value of each pixel is calculated from the skin groove image based on the skin groove image data, and the gloss density value of the skin groove part is calculated based on the brightness value. Similarly, the brightness value of each pixel is calculated from the skin image based on the skin image data, and the gloss density value of the skin area is calculated based on the brightness value. The calculated gloss density value of the skin groove image and the calculated gloss density value of the skin mound image are each output to the gloss density ratio calculation unit 9. Further, the skin image data is output from the gloss density calculation unit 8 to the gloss area ratio calculation unit 10. Since the gloss density is calculated based on the brightness value, the higher the brightness value, the higher the gloss density, and the lower the brightness value, the lower the gloss density.

  The gloss density ratio calculation unit 9 is based on the gloss density value of the skin groove image and the gloss density value of the skin image calculated by the gloss density calculation unit 8, and the gloss of the skin image with respect to the gloss density value of the skin image. The density value ratio is calculated as the gloss density ratio. The calculated gloss density ratio is output to the gloss evaluation unit 11.

  The gloss area ratio calculation unit 10 calculates the gloss area ratio of the skin mound image. Specifically, in the skin image, the area of density greater than a certain value is calculated as the area of the gloss region of the skin image, and the area of the gloss region of the skin image is divided by the area of the entire skin image. The gloss area ratio of the hide hill image is calculated. The calculated gloss area ratio of the skin image is output to the gloss evaluation unit 11.

  The gloss evaluation unit 11 calculates a product of the gloss density ratio calculated by the gloss density ratio calculation unit 9 and the gloss area ratio calculated by the gloss area ratio calculation unit 10 as an evaluation value, and uses that as an index of glossiness The glossiness of the skin of the face of the subject F is evaluated.

Next, an operation of the skin evaluation apparatus 1 according to Embodiment 1 of the present invention and a skin evaluation method performed by the skin evaluation apparatus 1 will be described.
The DSC 2 is operated by the operator to capture a total reflection image of the skin of the subject F, and the operator operates the polarizing filter 3 and the polarization measurement camera 4 to capture an internal scattering image of the skin of the subject F. Then, the total reflection image data is output from the DSC 2 to the specular reflection image creation unit 5, and the internal scattering image data is output from the polarimetry camera 4 to the specular reflection image creation unit 5 and the mask image creation unit 6.

The specular reflection image creation unit 5 creates a specular reflection image by subtracting the internal scattering image data from the total reflection image data, and the mask image creation unit 6 is based on edge detection and luminance values for the internal scattering image. A skin groove mask image is created by performing binarization, and a skin mound mask image is created by inverting the skin groove mask image. The specular reflection image created by the specular reflection image creation unit 5 is output as specular reflection image data to the skin groove image / skin image creation unit 7, and the skin groove mask image and the skin hill created by the mask image creation unit 6. The mask image is output to the skin groove image / skin image creating section 7 as skin groove mask image data and skin mask image data, respectively.
The skin groove image / skin image creation unit 7 creates a skin groove image from the specular reflection image data and the skin groove mask image data, and creates a skin mound image from the mirror reflection image data and the skin mask image data. And output to the gloss density calculation unit 8 as skin groove image data and hide hill image data.

The gloss density calculation unit 8 calculates the gloss density value of the skin groove image and the gloss density value of the skin mound image from the luminance values of the skin groove image and the skin mound image, and outputs them to the gloss density ratio calculation unit 9. At the same time, the gloss density value of the skin mound image is output to the gloss area ratio calculation unit 10.
The gloss density ratio calculation unit 9 calculates the average value of luminance in the skin groove image as the gloss density value of the skin image, and similarly calculates the average value of luminance in the skin image as the gloss density value of the skin image. The ratio of the gloss density value of the skin mound image to the gloss density value of the skin groove image is calculated as the gloss density ratio from the gloss density value of the skin groove image and the gloss density value of the skin mound image. The calculated gloss density ratio is output to the gloss evaluation unit 11.
Further, the gloss area ratio calculation unit 10 calculates the area of the skin image having a predetermined luminance or higher as the gloss region of the skin image, and calculates the area of the entire skin area relative to the area of the skin region. Is calculated as the gloss area ratio. The calculated gloss area ratio is output to the gloss evaluation unit 11.

The gloss evaluation unit 11 obtains the product of the gloss density ratio calculated by the gloss density ratio calculation unit 9 and the gloss area ratio calculated by the gloss area ratio calculation unit 10, and uses this as an evaluation value for evaluating the glossiness. The glossiness of the skin of the face of the subject F is evaluated based on the evaluation value.
As shown in FIG. 4, for example, when the correspondence between the product of the gloss density ratio and the gloss area ratio and the subjective evaluation value of 10 levels by the human eye is taken as a graph, a positive correlation is obtained as indicated by the dotted line region L as shown in FIG. There was a relationship. This indicates that the evaluation of skin glossiness according to the evaluation method of the present invention corresponds to the subjective evaluation, unlike the conventional evaluation value considered to be uncorrelated with the subjective evaluation value shown in FIG. . The 10-level subjective evaluation value indicates that the glossiness is lower as the numerical value is closer to 1, and the glossiness is higher as the evaluation value is closer to 10.

  As described above, by evaluating the skin glossiness using the skin evaluation method according to the first embodiment, it is possible to objectively evaluate the skin glossiness corresponding to the subjective evaluation by human eyes. .

Embodiment 2
For example, as shown in FIG. 5, the skin is centered on three glossy indices, “gloss intensity (average value of luminance)”, “intensity non-uniformity” and “area non-uniformity”. The area corresponding to the glossiness (“tekari”, “shiny”, “matte”) can be expressed on the graph.
The “intensity non-uniformity” can be expressed by the gloss density ratio calculated by the gloss density ratio calculation unit 9 in the first embodiment, and the “area non-uniformity” is the gloss area ratio calculation unit 10. It can be expressed by the gloss area ratio calculated in (1).
Therefore, the gloss density calculation unit 8 calculates the average value of the entire luminance including the skin groove image and the skin mound image, and the calculated average value of the luminance and the gloss density ratio calculation unit 9 calculate the gloss density ratio. Then, the evaluation values are plotted on the graph shown in FIG. 5 based on the gloss area ratio calculated by the gloss area ratio calculation unit 10. As a result, the glossiness of the skin can be classified into “tekari”, “shiny”, “matte”, etc., according to the area where the evaluation values are plotted.
As described above, not only the intensity of gloss (in the z-axis direction) but also non-uniformity in gloss (intensity non-uniformity (in the x-axis direction) and non-uniformity in area (in the z-axis direction) (y-axis direction) and xy plane) play an important role. Therefore, the skin glossiness is evaluated by using the skin evaluation method according to the second embodiment. The glossiness of the skin can be evaluated with words corresponding to the subjective evaluation by the human eye.

Embodiment 3
In the first embodiment, the gloss density ratio calculation unit 9 calculates an average value of the luminance in the skin groove image as the gloss density value of the skin image, and also calculates the luminance of the skin image as the gloss density value of the skin image. The average value is calculated, and the gloss density ratio is calculated from the gloss density value of the skin groove image and the gloss density value of the hide hill image. Instead of the average value of these brightness values, the mode value of the brightness is calculated. The gloss density value may be calculated, or the minimum luminance value may be calculated as the gloss density value.
Even if these values are used as the gloss density values, the skin glossiness corresponding to the subjective evaluation by the human eye can be objectively evaluated as in the first embodiment.

Embodiment 4
In the first embodiment, the product of the gloss density ratio calculated by the gloss density ratio calculation unit 9 and the gloss area ratio calculated by the gloss area ratio calculation unit 10 is used as the evaluation value. The evaluation value may be a linear sum of the gloss area ratio. By using the linear sum as an evaluation value, for example, it is possible to increase the weight of the gloss density ratio by emphasizing the gloss density ratio among the gloss density ratio and the gloss area ratio, or emphasize the gloss area ratio. Therefore, the weight of the gloss area ratio can be increased.
By using a linear sum as an evaluation value, after increasing the influence of either the gloss density ratio or the gloss area ratio, the skin gloss corresponding to the subjective evaluation by the human eye, as in the first embodiment. Sexual evaluation can be performed objectively.

Embodiment 5
In Embodiment 1, only the skin mound image data is output from the gloss density calculation unit 8 to the gloss area ratio calculation unit 10, but in addition to this, the skin groove image data may be output.
In this case, the gloss area ratio calculation unit 10 calculates the area of a region having a predetermined luminance or higher as a skin mound region based on the skin image data, and calculates a region having a predetermined luminance or lower based on the skin groove image data. The area is calculated as a skin groove area, and the ratio of the area of the skin groove area to the area of the skin mound area is calculated as a gloss area ratio, and is output to the gloss evaluation unit 11.
Even if these values are used as the gloss area ratio, it is possible to objectively evaluate the glossiness of the skin corresponding to the subjective evaluation by the human eye as in the first embodiment.

In the first to fifth embodiments, the gloss density ratio calculation unit 9 calculates any one of the average value, the mode value, and the minimum value of the luminance and uses it as the gloss density value. Instead of the glossiness index, a luminance gradient may be calculated, and any one of an average value, a mode value, and a minimum value of the luminance gradient may be calculated and used as the gloss density value.
For example, calculate multiple luminance gradients from the highest luminance part of the skin hill to the lower skin groove part, and calculate either the average value, the mode value, or the lowest value of the luminance gradient, and the gloss density value It is good.

  The skin evaluation method of the present invention has been described in detail above. However, the present invention is not limited to the above-described embodiment, and various improvements and modifications are made without departing from the gist of the present invention. Also good.

  DESCRIPTION OF SYMBOLS 1 Skin evaluation apparatus, 2 Digital still camera (DSC), 3 Polarization filter, 4 Polarization measurement camera, 5 Specular reflection image creation part, 6 Mask image creation part, 7 Skin groove image / skin image creation part, 8 Gloss density calculation Part, 9 gloss density ratio calculation part, 10 gloss area ratio calculation part, 11 glossiness evaluation part, C skin groove part, F test subject.

Claims (6)

Create a total reflection image by photographing the skin with normal light image measurement,
Create an internal scattering image by photographing the skin with polarized image measurement,
A specular reflection image is created from the created total reflection image and the internal scattering image, and the internal scattering image is separated into a skin groove portion and a skin hill portion on the skin surface. Calculating the position information of the hide hill,
A skin groove image, which is an image showing the glossiness of the skin groove part, is created from the specular reflection image and the positional information of the skin groove part, and from the mirror reflection image and the positional information of the skin part, Create a dune image that shows the glossiness,
Each gloss density value is calculated from the skin groove image and the skin mound image,
While calculating a gloss area ratio indicating an area ratio equal to or higher than a predetermined luminance from the skin mound image, calculating a gloss density ratio from the gloss density value of the skin groove and the gloss density value of the skin mound,
An evaluation value of skin is calculated from the gloss area ratio and the gloss density ratio, and skin glossiness is evaluated based on the evaluation value.   The skin evaluation method according to claim 1, wherein the gloss density value includes any one of an average value, a mode value, and a minimum value of luminance.   The skin evaluation method according to claim 1, wherein the evaluation value is a linear sum of the gloss area ratio and the gloss density ratio.   3. The skin glossiness is evaluated from a region including the evaluation value plotted by plotting the evaluation value on coordinates with the gloss area ratio and the gloss density ratio as axes. The skin evaluation method described in 1. Create a total reflection image by photographing the skin with normal light image measurement,
Create an internal scattering image by photographing the skin with polarized image measurement,
A specular reflection image is created from the created total reflection image and the internal scattering image, and the internal scattering image is separated into a skin groove portion and a skin hill portion on the skin surface. Calculating the position information of the hide hill,
A skin groove image, which is an image showing the glossiness of the skin groove part, is created from the specular reflection image and the positional information of the skin groove part, and from the mirror reflection image and the positional information of the skin part, Create a dune image that shows the glossiness,
Each gloss density value is calculated from the skin groove image and the skin mound image,
An area having a predetermined luminance or less is obtained from the skin image as an area of the skin groove area, an area having a predetermined luminance or more is obtained from the skin image as the area of the skin area, and the skin with respect to the skin area is obtained. The ratio of the area of the hill area is calculated as the gloss area ratio, and the gloss density ratio is calculated from the gloss density value of the skin groove and the gloss density value of the skin hill,
An evaluation value of skin is calculated from the gloss area ratio and the gloss density ratio, and skin glossiness is evaluated based on the evaluation value. A normal light image creation unit that creates a total reflection image by photographing the skin by normal light image measurement;
A polarization image creation unit that creates an internal scattering image by photographing the skin by polarization image measurement;
A specular reflection image creating unit for creating a specular reflection image from the created total reflection image and the internally scattered image;
A position information calculation unit that separates the internal scattering image into a skin groove part and a skin hill part on the skin surface, and calculates position information of the skin groove part and position information of the skin part;
A skin groove image that is an image showing the glossiness of the skin groove part is created from the specular reflection image and the position information of the skin groove part, and the skin part is obtained from the specular reflection image and the position information of the skin part. A skin groove image / skin image creation unit that creates a skin mound image that is an image showing the glossiness of the image,
A gloss density calculation unit for calculating a gloss density value of each from the skin groove image and the hide hill image,
A gloss density ratio calculation unit for calculating a gloss density ratio based on the gloss density value of the skin groove image and the gloss density value of the hide hill image;
A gloss area ratio calculating unit for calculating a gloss area ratio indicating an area ratio equal to or higher than a predetermined luminance from the skin mound image;
A skin evaluation apparatus, comprising: a gloss evaluation unit that calculates an evaluation value from the gloss area ratio and the gloss density ratio and evaluates the gloss of the skin based on the evaluation value.

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