JP2000350702A - Measurement method and apparatus for cutaneous constituents and characteristics - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method and apparatus for measuring the quantities of cutaneous consituents such as melanin and cutaneous characteristics of spots and freckles on a face with high preciseness. SOLUTION: In an illumination photo-detective optical system portion 12 of this apparatus, the light of an optical source produces a diffuse reflection on the internal wall surface of an integrating sphere and illuminates uniformly a measurement specimen 16, and in the light which reflects on the surface of the measurement specimen, the light which reflects at a certain angle enters the photo-detective optical system and is processed at a colorimetric-value arithmetic processor portion 14. In this case, the data of colorimetric values of the skin and the quantities of cutaneous constituents are subjected to multiple regression analysis and a multiple regression formula is obtained in advance. By using this multiple regression formula, the quantity of at least one substance selected from groups consisting of such cutaneous constituents as melanin, hemoglobin oxide and reductive hemoglobin is obtained from the colorimetric values of the skin, and the content in the skin is measured.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and an apparatus for measuring skin components and skin characteristics, and more particularly to a method of multiple regression analysis for determining the amount of skin components and skin from colorimetric values of skin. The present invention relates to a measuring method and a measuring device for determining the characteristics of a device.

[0002]

2. Description of the Related Art The color of the skin is determined by the pigment components constituting it. However, it is a cosmetic point of view that is generally required to be so-called "white", and the "under the eyes" which is one guideline indicating an unhealthy state. It is an important characteristic for humans from the viewpoint of diagnosing the health condition as shown by "bear".

[0003] From the viewpoint of cosmetic whitening, which is to obtain fair skin, the skin color is the ultimate goal. In general, the formation of melanin pigments, which is reflected in the darkening and whitening of the pigment, is suppressed. This melanin pigment appears on the surface of the skin as spots and freckles.

In order to suppress the production of melanin and obtain so-called fair skin, cosmetics, which are generally called whitening cosmetics, have been actively developed in the field of cosmetics. And
In the development of this whitening cosmetic, there has been a demand for directly measuring the amount of melanin in addition to the skin color as a guideline of the whitening effect. There is also a demand for measuring the distribution of spots and freckles when looking at skin color.

In other words, by directly and independently evaluating the effects of local skin melanin and a wide range of skin spots and freckles, it is possible to accurately evaluate one of the whitening effects of whitening cosmetics. Is required. When it is intended to evaluate the former melanin content in the skin, it is actually difficult to directly measure the melanin content, and therefore, the evaluation is made from the skin color, and the skin color is measured using a conventional colorimeter. The lightness index L * value in the L * a * b * color system is evaluated. In other words, whitening cosmetics were applied to the skin, and it was determined that the melanin increased when the L * value decreased and the melanin decreased when the L * value increased, and the effect of the whitening cosmetics on melanin, that is, the whitening effect was evaluated.

[0006] However, it has been found that the L * value certainly decreases when the melanin increases, but that the L * value is low does not always mean that the melanin is high.
That is, inflammation (erythema) occurs in the skin, blood in the skin increases, and hemoglobin (including oxyhemoglobin and reduced hemoglobin), which is a pigment, increases, so that the L * value of the skin also decreases.

[0007] Therefore, when the L * value of the skin decreases, it cannot be distinguished whether it is due to an increase in melanin or an increase in hemoglobin due to inflammation.
* Even if the value was increased, it could not be accurately evaluated as a whitening effect of a whitening cosmetic, particularly an effect of suppressing the production of melanin. In addition, from the viewpoint of measuring a person's health due to the need to maintain health, for example, "bears under the eyes"
It is not enough to evaluate the color of a congested part such as the like, and it is required to specify and measure the components constituting the part, especially to specify and measure a specific hemoglobin species. However, there is no simple way to evaluate it.

In other words, for example, it is conceivable to apply the same conventional colorimetry as described above to a congested part such as a "bear under the eyes". It is not possible to fully determine what proportion of the skin is composed of what components,
Evaluating congested areas, such as "bears under the eyes," may not be sufficient to accurately grasp and maintain a person's health.

In such a situation, a conventional colorimeter is used to evaluate general objects, while a mexameter (a meter) is used as a measuring device for directly evaluating the amount of skin melanin and hemoglobin. Mexameter: C + K
Has been developed and used for skin evaluation. This mexameter measures 568 nm (referred to as Green) and 660 nm on the skin to be evaluated.
(Referred to as Red) and 880 nm (Infrare).
Called d. ) Is a device comprising a reflectance measuring unit for measuring reflectance at three wavelengths and a control unit for analyzing the obtained data to calculate and display the amounts of melanin and hemoglobin.

The principle of measurement of this mexameter is roughly as follows. In the evaluation of the amount of melanin, Red
Since there is almost no blood absorption between and Infrared, melanin is obtained by subtracting the absorbance obtained from the reflectance obtained by measurement with Infrared from the absorbance obtained from the reflectance obtained by measurement with Red. Is required. Similarly, in the evaluation of blood,
Since there is a peak of absorbance near green and there is almost no absorption at Red, the absorbance obtained from the reflectance obtained by measurement at Red from the absorbance obtained from the reflectance obtained by measurement at Green is By subtraction, the amount of blood, and thus the amount of hemoglobin (including both oxyhemoglobin and reduced hemoglobin) is determined.

On the other hand, with respect to the latter evaluation of skin spots and freckles, a method using an ultraviolet photograph (Seiichi Arai et al., JOURNAL OF SCCJ 23, 31 (1)
989)) and a method using a video microscope (Yuko Shibue et al. JOURNAL OF SCCJ 2
6, 120 (1992)). Also,
The present applicant has already developed a system for selecting an arbitrary part of the face in an arbitrary form using a normal TV camera, and extracting and measuring the spots and freckles of the part. (Yuji Masuda et al. JOURNAL OF SCCJ 28,147
(1994)).

[0012]

However, the mexameter used for estimating the amount of melanin in the local skin in the former is based on Green's principle of measurement.
By subtracting the absorbance determined from Red from the absorbance determined from, the amount of hemoglobin is certainly determined, but there is also a difference in the absorbance of melanin in those wavelength ranges, and the amount of hemoglobin is calculated by subtracting as it is. There is a problem that the measurement accuracy is affected by being added excessively.

A first object of the present invention is to provide a measuring method and a measuring apparatus capable of measuring the amount of melanin and other components in the skin with high accuracy by using an inexpensive colorimetric device having a simple structure and operation. Is to provide. On the other hand, the latter system for extracting and measuring the spots and freckles of an arbitrary part of the face using a TV camera developed by the present applicant to evaluate the broad range of skin spots and freckles is used at the time of shooting. It has been known that when the skin becomes reddish due to tension or the like, it affects the measurement accuracy of spots and freckles.

Accordingly, a second object of the present invention is to provide a measuring method and a measuring apparatus capable of measuring skin spots and freckles of the skin with higher accuracy.

[0015]

According to the method of measuring a component in the skin according to the present invention, a multiple regression equation is obtained in advance by performing a multiple regression analysis on colorimetric values of the skin and data on the amounts of the components in the skin. The amount of at least one substance selected from the group consisting of melanin, oxyhemoglobin, and reduced hemoglobin, which are components in the skin, is determined from the colorimetric value of the skin using the formula.

As a result, components in the skin can be measured with higher accuracy than in a conventional colorimeter. In this case, when the colorimetric value is a tristimulus value in the XYZ color system, the effects of the present invention described above can be suitably exhibited, and in particular, a combination with a method for measuring skin characteristics described below. Thus, the measurement accuracy of the skin characteristics can be improved.

Further, in this case, for the melanin of the components in the skin to be measured, the contribution to the melanin measurement value due to the pseudo-correlation of melanin with oxyhemoglobin and reduced hemoglobin is corrected to eliminate the error. Then, components in the skin can be measured with higher accuracy, and the measurement accuracy of skin characteristics can be further improved.

Further, the apparatus for measuring a component in the skin according to the present invention obtains an illuminating / receiving optical system for obtaining reflected light from the skin, and a colorimetric value. And a colorimetric value calculation controller for determining the amount of at least one substance selected from the group consisting of melanin, oxyhemoglobin, and reduced hemoglobin.

[0019] This makes it possible to measure skin components with high accuracy by using an inexpensive colorimeter that is simple in structure and operation. Further, the method for measuring skin characteristics according to the present invention includes the steps of: digitally processing an image obtained by capturing an image of a skin state to create an image of an RGB color system RGB value; and generating an image of the RGB color system RGB value. RG for each pixel
An XYZ color system XYZ value is obtained from the B value, and an image of the amount of the component in the skin is created using the method for measuring a component in the skin according to any one of claims 1 to 3. It is characterized by.

This makes it possible to measure the skin characteristics with high accuracy. Particularly, even when the amount of oxyhemoglobin and reduced hemoglobin in the skin changes, such as when the skin becomes reddish, the skin characteristics are improved. It can be measured with accuracy. Further, in this case, the image of the component amount in the skin is smoothed to create a smoothed image of the component amount in the skin, and the image of the component amount in the skin and the smoothing of the component amount in the skin are performed. If the difference in the amount of the component in the skin at each pixel of each image is calculated and a difference image of the amount of the component in the skin is created and used as an index of spots and freckles, the skin characteristics can be more appropriately measured.

Further, the skin characteristic measuring apparatus according to the present invention comprises an image pickup section for picking up an image of a skin condition, and digitally processing an image picked up by the image pickup section to obtain an RGB value of an RGB color system. An image is created, an XYZ color system XYZ value is obtained from the RGB value for each pixel of the RGB color system RGB value image, and a component amount in the skin in the skin is obtained from the XYZ color system XYZ value. To create an image of the amount of components in the skin, further smoothing the image of the amount of components in the skin to create a smoothed image of the amount of components in the skin, an image of the amount of components in the skin and An image processing control unit that calculates a difference in the amount of the component in the skin at each pixel of each of the smoothed images of the amount of the component in the skin to create a difference image of the amount of the component in the skin, and uses it as an index of spots and freckles; It is characterized by having.

Thus, the skin characteristics can be measured with high accuracy.

[0023]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, a preferred embodiment (hereinafter referred to as an embodiment) of a method and an apparatus for measuring components in skin and skin characteristics according to the present invention will be described with reference to drawings and relational expressions. I will explain. As a first example of this embodiment, a method and an apparatus for measuring the amounts of melanin, oxyhemoglobin, and reduced hemoglobin, which are components in the skin, for a local portion of the skin by the method of the present invention will be described. Here, oxyhemoglobin and reduced hemoglobin are collectively handled as hemoglobin, but it goes without saying that the amounts of oxyhemoglobin and reduced hemoglobin can be handled independently.

First, the colorimetric unit and the arithmetic and control unit of the measuring device to be used will be described. In this case, as the measuring device, for example, a spectrophotometer (CM-2002 manufactured by Minolta), which is a commercially available colorimeter, can be used. As shown in FIG. It comprises an illumination / light receiving optical system section 12 and a colorimetric value calculation control section 14. The illumination / light receiving optical system unit 12 uniformly diffuses the light of the light source on the inner wall surface of the integrating sphere to illuminate the measurement sample 16, and the light reflected at a predetermined angle out of the light reflected on the measurement sample surface The light enters the system and is processed by the colorimetric value calculation control unit 14. That is, the colorimetric data of the local skin measured in the C light source and the two-degree field of view is converted from the reflectance spectrum to the XYZ color system.

On the other hand, a colorimetric device different from the spectrocolorimeter 10, for example, the above-mentioned mexameter, is used to obtain control data. Each content of melanin, oxyhemoglobin and reduced hemoglobin in the local skin measured using this mexameter is regarded as a certain reliable value. The present invention is not limited to this mexameter, and by using a more reliable apparatus for measuring melanin, oxyhemoglobin, and reduced hemoglobin to obtain control data, more favorable effects can be obtained in the present invention.

As a method for measuring melanin, oxyhemoglobin and reduced hemoglobin in such local skin with higher measurement accuracy, the present applicant has already studied a method using a reflection spectrum of the skin. . In the method using the skin reflection spectrum, the amount of the constituent components of the skin is obtained by placing an absorbance model based on the Lambert-Beer law from the skin reflection spectrum. That is, the contribution of each component is determined by fitting a combination of the reflection spectra of each component such as melanin and oxyhemoglobin with the curve of the reflection spectrum of the skin using a multiple regression analysis technique. In this case, the wavelength region of the reflection spectrum is 50
By applying only within the range of 0 to 700 nm,
It has been found that melanin, oxyhemoglobin and reduced hemoglobin can be measured with high accuracy.

Therefore, by applying an apparatus using the above-described principle of measuring the reflection spectrum as a colorimetric apparatus for obtaining the reference data, a more favorable effect can be obtained in the present invention. Next, multiple regression analysis is performed using the colorimetric values of the skin measured by the spectrocolorimeter 10 and the respective data of the components in the skin measured by, for example, an apparatus using the above-described principle of measuring the reflectance spectrum. The procedure for obtaining the colorimetric value and the multiple regression equation for the components in the skin will be described.

XY as the colorimetric value of each person's cheeks using a spectrophotometer with 60 young and old women as subjects.
Z tristimulus values were determined. The significance of the XYZ tristimulus values is that the X stimulus value indicates the intensity of red, the Y stimulus value indicates the intensity of green, and Z
It can be seen that the stimulus value indicates the intensity of blue, respectively. On the other hand, the same melanin and hemoglobin content in the skin of the cheek of each of the 60 young and old women was determined using an apparatus using the principle of measurement of reflection spectrum.

The amounts of melanin and hemoglobin in the skin were assumed to be calculated by the following multiple regression equation. Melanin content = Mx × log10 (1 / X) + My × log10 (1 / Y) + Mz × log10 (1 / Z) + nm Hemoglobin content = Hx × log10 (1 / X) + Hy × log10 (1 / Y) + Hz × log10 (1 / Z) + nh Then, multiple regression analysis was performed using the above data, and Mx ~
Mz, Hx to Hz and nm, nh were calculated to obtain the following multiple regression equation.

Melanin content = −4.861 × log10 (1 / X) + 1.268 × log10 (1 / Y) + 4.669 × log10 (1 / Z) +0.063 (1-1) Hemoglobin content = −32 .218 × log10 (1 / X) + 37.499 × log10 (1 / Y) −4.495 × log10 (1 / Z) +0.444 (1-2) Calculated from the above multiple regression equation, ie, colorimetry The correlation between the melanin and hemoglobin amounts (horizontal axis) of each of the 60 individuals determined from the values and the amounts of melanin and hemoglobin (vertical axis) of each of the 60 individuals measured using an apparatus using the principle of measurement of reflection spectrum. As shown in FIG. Here, the unit of the amount of melanin and the amount of hemoglobin are mol · cm. For the amount of melanin, R = 0.945, for the amount of hemoglobin, R =
0.990, respectively, a high correlation coefficient is obtained,
It can be seen that the amount of melanin and hemoglobin in the skin can be accurately measured from the colorimetric values obtained by the spectrophotometer of the present invention.

The above-mentioned multiple regression equation is incorporated in the colorimetric value calculation control unit 14 of the spectrophotometer 10, and the amount of melanin and the amount of hemoglobin are obtained from the XYZ values. Here, in order to verify the usefulness of the method and apparatus for measuring components in skin according to the first example of the present embodiment, L * in a conventional L * a * b * color system was used as a comparative example. The skin (hand) was immersed in a warm bath at 47 ° C. for 3 minutes using a colorimeter using the value and a * value, and then the skin was drawn up from the warm bath for 60 minutes. The change in the amount of components in the medium was examined. FIG. 3A shows the result according to the first example of the present embodiment, and FIG. 3B shows the result of the L * value and the a * value measured using a conventional colorimeter. The horizontal axis is
Elapsed time (unit: m)
In FIG. 3 (a), the vertical axis indicates the amount of components in the skin (unit: mol · cm), and in FIG. 3 (b), the L * value and the a * value (unit: non-dimensional) Is shown. Here, the L * value is an index indicating the amount of melanin, and the a * value is an index indicating the amount of hemoglobin. In addition, the data at the left end in each figure show values before immersion in a warm bath.

In the first example of this embodiment shown in FIG. 3A, the amount of hemoglobin rapidly increases immediately after immersion in a warm bath, and gradually decreases thereafter, but even after 60 minutes. At a high level. On the other hand, the amount of melanin also shows the same tendency as the amount of hemoglobin, but the degree of increase is small and is only about 1/5 of the increase rate of the amount of hemoglobin. On the other hand, in the case of the comparative example, the a * value which is an index of the amount of hemoglobin shows almost the same tendency as that of the first example of the present embodiment, but L which is an index of the amount of melanin. Unlike the case of the first example of the present embodiment, the * value shows a tendency to increase considerably immediately after immersion in a warm bath similarly to the case of the a * value which is an index of hemoglobin amount.

It is generally known that when the skin is immersed in a warm bath, the amount of hemoglobin actually increases, while the amount of melanin does not change. Therefore, the results in the case of the first example of the present embodiment in which the measured value of the melanin has changed and in the case of the comparative example are both inappropriate. However, the rate of change (the maximum value of the amount of melanin immediately after immersion in FIG. 3 (a) / the value of the amount of melanin before immersion, the minimum value of the L * value immediately after immersion in FIG. 3 (b) /
From the viewpoint of (L * value before immersion), the rate of change is smaller in the first example of this embodiment than in the comparative example.
It can be said that the first example of the present embodiment is a relatively better measurement method and measurement device than the comparative example.

The reason why the measured value of melanin which should not actually change in each of the above-described measuring methods changes is that in the first example of the present embodiment, the melanin amount is almost directly It can be considered that the errors of the multiple regression analysis formula and the measurement errors of the measuring device have been accumulated despite the fact that they are measured in the meantime.
It is considered that the absorption spectrum of hemoglobin and the absorption spectrum of melanin overlap due to the measurement principle.

Here, using the measuring method and measuring apparatus of the first example of the present embodiment, assuming that the skin is tanned by being irradiated with ultraviolet rays and becomes reddish, 2 MED ultraviolet rays are applied to the arm part. FIG. 4 shows the results of measuring the change over time in the amount of components in the skin when artificially irradiating and causing sunburn over 16 days immediately after the ultraviolet irradiation. FIG.
The abscissa indicates the number of days (unit: day) after irradiation with ultraviolet rays, and the ordinate indicates the change in the amount of component (unit: mol · cm).

The amount of melanin tends to rapidly increase immediately after irradiation with ultraviolet light, and then gradually decrease. Although this tendency is appropriate for the time being, it is not necessarily reasonable from the viewpoint of other findings that the temperature rises shortly after irradiation with ultraviolet light.
On the other hand, the hemoglobin amount tends to rapidly increase immediately after ultraviolet irradiation, then rapidly decrease again, and recover to almost the level before ultraviolet irradiation in a short period of time. It seems to be a good result.

For this reason, it will be considered to correct the value of melanin with the value of hemoglobin based on the above results when the skin is immersed in a warm bath. That is, the value of the amount of melanin at each elapsed time when the skin is immersed in a warm bath is apparently increasing because there is a pseudo-correlation between the amount of melanin and the amount of hemoglobin in the above measurement results. Was determined to be a constant value without changing the value of the melanin amount at each elapsed time. Specifically, a relational expression between the change in the amount of melanin and the amount of hemoglobin was obtained using the above data, and this was used as a correction term for the amount of melanin.

The relational expression between the obtained change in the amount of melanin and the amount of hemoglobin is as follows: change in the amount of melanin = 0.219 × amount of hemoglobin + 0.008 (2-1). The relation number R was 0.946. Therefore, the corrected melanin amount is obtained by the following expression: corrected melanin amount = melanin amount− (0.219 × hemoglobin amount + 0.008) (2-2). Here, in the equation (2-2), the melanin amount and the hemoglobin amount on the right side are values before correction. In addition,
This method of correcting the amount of melanin is an example, and is not limited thereto.If a relational expression between a change in the amount of melanin and a hemoglobin amount having a higher correlation by another measurement condition is obtained, the expression can be applied. .

In order to verify the validity of the above-mentioned correction formula (2-2) for the amount of melanin, the measurement method and the measurement apparatus of the first example of the present embodiment were used, and the skin was immersed in a warm bath. FIG. 5 shows the results of correcting the amount of melanin and the amount of melanin when irradiated with ultraviolet rays using the above-described correction formula (2-2) for the amount of melanin. In FIG. 5, (a) shows the results when the skin is immersed in a warm bath, and (b) shows the results when the skin is irradiated with ultraviolet rays.

When the skin in (a) is immersed in a warm bath, the melanin content after correction shows a substantially constant value regardless of the passage of time, which is the same as the original data (value before correction) in (a). Although it can be said that the correction formula (2-2) is based on the fact that the correction formula (2-2) is created based on the correction formula (2-2), on the other hand, in the case of irradiating the ultraviolet light of (b), the corrected melanin amount gradually increases as the number of days elapses. It shows a tendency to increase, and the unnatural tendency of the melanin amount before correction to increase on a short day was eliminated, and therefore, it was found that this correction formula was valid.

Next, as a second example of the present embodiment,
A description will be given of a method and an apparatus for measuring skin characteristics for measuring the distribution of the amount of melanin as skin characteristics, that is, the distribution of spots and freckles over a wide area of the face. FIG. 6 schematically shows a configuration of a skin characteristic measuring device according to a second example of the present embodiment.

The measuring device 100 includes an illumination box 102
, A television camera 104 as an imaging / colorimetry unit, an image analysis processor 106 as an image processing control unit, and a host computer 108. Here, the illumination box 012 is for capturing a face image under the same conditions, and is provided with a television camera (SONY XC-00).
7) 104 is for capturing a facial image,
Image analysis processor (NEXUS 6800) 106
And host computer (SUN Spacest)
An operation 2) 108 is for digitizing the captured image and performing arithmetic processing from the image.

A method for measuring facial spots and freckles as skin characteristics using the skin characteristic measuring apparatus 100 will be described. The measurement procedure is roughly as follows, as shown in FIG. (1) First, the face of the subject is imaged in the lighting box 102 (S1). (2) The RGB color system is converted from the RGB color system to the XYZ color system for each pixel of the captured RGB color system image. Further, the XYZ values of the XYZ color system are converted into the amount of melanin according to the formula (1-1) to create an image of the amount of melanin (S2-1). This is called an original melanin image. Note that, in this case, when converted into the amount of hemoglobin according to the equation (1-2), the image of the amount of hemoglobin can be shown together. (3) In parallel with the above, an original image of melanin is smoothed to create an image free from spots and freckles (S2-
2). This is called a melanin smoothed image. (4) The difference between the amount of melanin and the amount of hemoglobin is calculated for each corresponding pixel of the original image of melanin and the smoothed image of melanin, and the image is created (S3). This is called a melanin difference image. The sum of pixels having a difference value of 0.2 mol · cm or more in the measurement range is calculated and used as an index of spots and freckles (S4).

The applicant of the present invention has conventionally determined the L * a * b * color system Lab values from the XYZ color system XYZ values in the above-described steps S2-1 and S2-2, and obtained the color difference image of the Lab values. To evaluate skin properties (see above,
Yuji Masuda and others JOURNALOF SCCJ 28,1
47 (1994)). The measurement procedure described above will be described more specifically. (1) Creation of the lighting box 102 In order to uniformly illuminate the face in the lighting box 102, 2
Ten halogen bulbs were arranged on the left, right, up, and down of the front surface of the illumination box 102 having a size of 2 × 2 m, and two halogen bulbs were arranged on the side surfaces. A C light source was created by arranging two color temperature conversion filters in the illumination box 102 (bulb: FUJI
JCV 100V 75WF, filter: RDS leuchrome filter II RB4, RB6). The average color rendering property evaluation number (reference light source IC) of the light source is 95.67. (2) Creation of original melanin image The conversion from the RGB color system to the XYZ color system at each pixel is performed by using the least squares method using the coefficients of a linear conversion equation that applies to the XYZ tristimulus values from the RGB image pickup tube characteristics. The following conversion formula was obtained.

X = 0.59R + 0.23G + 0.18B (3-1) Y = 0.31R + 0.60G + 0.09B (0 ≦ Y ≦ 100) (3-2) Z = 1.00B (3-3) , The XYZ tristimulus value (X
(YZ value) was converted to the amount of melanin to prepare a melanin amount original image. (3) Creation of a Smoothed Melanin Image In this measurement, the entire face is taken in a size of 512 × 480 pixels, so one pixel corresponds to a size of about 0.5 mm. The moving average method was used for smoothing, but when the moving distance was small, large spots such as senile pigment spots caused a hollow in the center, and when the moving distance was large, wrinkles on the face were easily picked up and measured. Was unsuitable for (not shown), the smoothing matrix was 25 × 25 (approximately 7.5 ×
7.5 mm2) pixels were employed. A melanin-smoothed image was created by the above procedure (not shown). (4) Calculation and Analysis of Index of Spots and Freckles The difference in the amount of melanin was calculated for each corresponding pixel of the original melanin image and the smoothed melanin image, and a melanin difference image was created. Based on the melanin difference,
Sobacas were classified by concentration and visualized and quantified. An example of the analysis is shown in FIG.

In this case, the difference in melanin amount is 0.2 mol.
-In the range of less than cm, since the color level is uneven due to the influence of image noise and hardly discernable by visual perception, the range in which the difference in melanin amount is 0.2 mol.cm or more is divided in increments of 0.2 mol.cm. , 0.2molcm
The range of not less than 0.4 mol · cm was regarded as thin spots and freckles, the range of 0.4 mol · cm to less than 0.6 mol · cm was regarded as medium spots and freckles, and the range of 0.6 mol · cm or more was determined as dark spots and freckles. .

FIG. 8A shows an imaged RGB color system RG.
What appeared as a single large pigment spot in the B-value image was classified according to the density of the color in the melanin amount difference image of (b), and the density of the spots and freckles and the face distribution thereof could be grasped. Next, in addition to the above measuring method, the above formula (1--) for calculating the amount of hemoglobin of the present invention is used.
2) and a procedure for applying the correction equation (2-2) for correcting and removing an error caused by hemoglobin on melanin measurement to remove the influence of hemoglobin more reliably will be described.

The image of the subject's face is captured in the illumination box (S1), and each pixel of the captured original image is converted from the RGB color system to the XYZ color system (in the middle of S2).
This is the same as the conventional measurement method. At the time of conversion to the XYZ color system, the equations (1-1) and (1-2) in the method for measuring the components in the skin according to the first example of the present embodiment are applied to each pixel to obtain XYZ. The melanin amount and the hemoglobin amount are obtained from the values, and the correction formula (2-2) is applied to each pixel to correct the effect of the hemoglobin amount and obtain the removed melanin amount.

As a result, the amount of melanin (stain, buckwheat) from which the influence of the amount of hemoglobin is more reliably eliminated is required. The procedure after obtaining the melanin content is the same as the method described above, that is, the original melanin image is smoothed to create a melanin smoothed image, and the melanin original image and the melanin smoothed image are formed. A difference in the amount of melanin is obtained for each pixel from the image, and a melanin amount difference image is created.

FIG. 9 shows a comparison between the measurement results of spots and freckles by the conventional measurement method and the measurement results by the measurement method of the present invention. Here, (a) is an original image of the captured RGB values, and (b) is L * a * b conventionally used by the present applicant.
* It is a color difference image of the color system Lab value, and (c) is a melanin difference image by the measurement method of the present invention. R imaged
The acne shown in the original image of the GB value is the result of irritation of the skin and an increase in the amount of hemoglobin in the blood in the skin, which is completely different from spot freckles caused by melanin. However, in the color difference image of the L * a * b * color system Lab value by the conventional measurement method, the color difference image is displayed as dark spots and freckles. On the other hand, in the melanin difference image obtained by the measurement method of the present invention, the acne portion has disappeared, and the problem that acne as reddish skin is erroneously determined as dark spots or freckles is eliminated.

[0051]

According to the method for measuring the components in the skin according to the present invention, multiple regression equations are obtained in advance by performing a multiple regression analysis on the colorimetric values of the skin and data on the amounts of the components in the skin. In order to determine the amount of at least one substance selected from the group consisting of skin components melanin, oxyhemoglobin and reduced hemoglobin from the skin colorimetric values, the skin with higher accuracy than conventional colorimeters The components therein can be measured.

In this case, when the colorimetric value is a tristimulus value in the XYZ color system, the above-mentioned effect of the present invention can be suitably exhibited, and in particular, a method for measuring skin characteristics described below. In combination, the measurement accuracy of the skin characteristics can be improved. Further, in this case, for the melanin of the components in the skin to be measured, the configuration is corrected to eliminate the error by correcting the contribution to the melanin measurement value by the pseudo correlation between melanin and oxyhemoglobin and reduced hemoglobin, and higher. The components in the skin can be measured with high accuracy, and the measurement accuracy of the skin characteristics can be further improved.

Further, according to the apparatus for measuring components in skin according to the present invention, an illumination / light receiving optical system for obtaining reflected light from the skin,
A colorimetric value calculation control unit that determines a colorimetric value and calculates the amount of at least one substance selected from the group consisting of melanin, a component in the skin, oxyhemoglobin and reduced hemoglobin, from the colorimetric value obtained by the colorimetric unit. And to have
The components in the skin can be measured with high accuracy by using an inexpensive device that is simple in structure and operation.

Further, according to the skin characteristic measuring method of the present invention, an image obtained by imaging the skin condition is subjected to digital image processing to create an image of the RGB color system RGB values.
X for each pixel of the image of the B color system RGB value
The XYZ value of the YZ color system is determined, and further, an image of the amount of the component in the skin is created using the above-described method for measuring the component in the skin, so that the skin characteristics can be measured with high accuracy. Even when the amount of oxyhemoglobin and reduced hemoglobin in the skin changes, such as when the skin becomes reddish, the skin characteristics can be measured with high accuracy.

In this case, the image of the component amount in the skin is smoothed to create a smoothed image of the component amount in the skin,
An image of the amount of components in the skin and a smoothed image of the amount of components in the skin Calculate the difference in the amount of components in the skin at each pixel to create a difference image of the amount of components in the skin, Then, the skin characteristics can be measured more suitably.

Further, the skin characteristic measuring device according to the present invention includes an image pickup section for picking up an image of the skin condition, and an image obtained by the image pickup section being digitally processed to obtain an image of the RGB color system RGB values. Is created, the XYZ color system XYZ values are determined from the RGB values for each pixel of the image of the RGB color system RGB values, and the component amounts in the skin in the skin are further determined from the XYZ color system XYZ values. An image of the component amount of the skin is further formed, and an image of the component amount in the skin is further smoothed to create a smoothed image of the component amount in the skin. To calculate a difference in the amount of component in the skin at each pixel of each smoothed image to create a difference image of the amount of component in the skin, and with an image processing control unit as an index of spots and freckles, with high accuracy Skin properties can be measured.

[Brief description of the drawings]

FIG. 1 is a diagram showing a schematic configuration of an apparatus for measuring components in skin according to a first example of the present embodiment.

FIG. 2 is a correlation diagram between a component amount calculated from a colorimetric value measured by a method for measuring components in skin according to a first example of the present embodiment and a sex component measured by another measurement method;
(A) shows the case where the component amount is the melanin amount, and (b) shows the case where the component amount is the hemoglobin amount.

FIG. 3 shows changes in the amount of components in the skin after the skin has been warmed in a warm bath, and (a) shows the measurement results obtained by the method for measuring the components in the skin according to the first example of the present embodiment. Show,
(B) shows a measurement result using a conventional colorimeter.

FIG. 4 is a diagram showing a result of measurement of a change in the amount of a component in the skin after ultraviolet irradiation by the method for measuring a component in the skin according to the first example of the present embodiment.

FIG. 5 is a diagram for explaining a result of correcting a contribution to a melanin measurement value due to a pseudo correlation between melanin, oxyhemoglobin, and reduced hemoglobin to remove an error,
(A) is a figure which shows the transition of the component amount in the skin after the skin is warmed by a warm bath, and (b) is a figure which shows the transition of the component amount in the skin after ultraviolet irradiation.

FIG. 6 is a diagram showing a schematic configuration of a skin characteristic measuring device according to a second example of the present embodiment.

FIG. 7 is a flowchart showing a schematic procedure of a skin characteristic measuring method according to a second example of the present embodiment.

FIGS. 8A and 8B show the results of measurement of the state of spots and freckles on the face by the skin characteristic measuring method according to the second example of the present embodiment, wherein FIG. 8A shows an original image taken, and FIG. 9 shows a melanin difference image.

9A and 9B are diagrams for explaining an effect of correcting a contribution to a melanin measurement value due to a pseudo correlation between melanin and hemoglobin to remove an error, wherein FIG. 9A is an original image taken, and FIG. 9) is a color difference image of Lab value, which is a conventional measurement method, and (c) is a melanin amount difference image after hemoglobin correction obtained by correcting the melanin amount difference image of FIG.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Spectrocolorimeter 12 Illumination / light receiving optical system part 14 Colorimetric value calculation control part 100 Skin characteristic measuring device 102 Illumination box 104 Television camera 106 Image analysis processor 108 Host computer

Claims (7)

[Claims] 1. A multiple regression equation is obtained in advance by performing multiple regression analysis on data of skin colorimetric values and component amounts in the skin, and the components in the skin are determined from the colorimetric values of the skin using the multiple regression equation. A method for measuring a component in skin, comprising determining an amount of at least one substance selected from the group consisting of melanin, oxyhemoglobin, and reduced hemoglobin. 2. The method according to claim 1, wherein the colorimetric values are tristimulus values in the XYZ color system. 3. The method according to claim 2, wherein the melanin of the components in the skin to be measured is corrected by correcting a contribution to a melanin measurement value due to a pseudo correlation between melanin, oxyhemoglobin, and reduced hemoglobin, thereby eliminating an error. The method for measuring a component in skin according to claim 1 or 2. 4. An illuminating / receiving optical system for obtaining reflected light from the skin, a colorimetric value is determined, and from the colorimetric values obtained by the colorimetric unit, melanin, oxyhemoglobin and reduced hemoglobin which are components in the skin are obtained. A colorimetric value calculation control unit for calculating an amount of at least one substance selected from the group consisting of: 5. An image obtained by imaging the condition of the skin is digitally image-processed to create an image of an RGB value in an RGB color system, and an image of the RGB value in the RGB color system is calculated from the RGB value for each pixel. XYZ color system XYZ values are determined, and an image of the amount of components in the skin is created using the method for measuring components in the skin according to any one of claims 1 to 3. A method for measuring skin characteristics. 6. An image of the component amount in the skin is created by smoothing the image of the component amount in the skin to create a smoothed image of the component amount in the skin. 6. The measurement of skin characteristics according to claim 5, wherein a difference in the amount of the component in the skin at each pixel of each image is calculated to create a difference image of the amount of the component in the skin and used as an index of spots and freckles. Method. 7. An image pickup unit for picking up an image of a skin condition, and an image obtained by the image pickup unit is converted into a digital image to generate an image of an RGB color system RGB value.
XY from the RGB values for each pixel of the image of the color system RGB values
The XYZ value of the Z color system is determined, and the XYZ color system XYZ
The component amount in the skin in the skin is determined from the value to create an image of the component amount in the skin, and the image of the component amount in the skin is further smoothed to obtain a smoothed image of the component amount in the skin. Create a difference image of the component amount in the skin by calculating the difference between the component amount in the skin in each pixel of the image of the component amount in the skin and the smoothed image of the component amount in the skin, An apparatus for measuring skin characteristics, comprising: an image processing control unit serving as an index of spots and freckles.