Test chart, image analysis device, image analysis system, image analysis method and program

Abstract

This test chart TC1 comprises a sheet material ST and a plurality of first skin reflection regions SA1-SA4 that are formed on the sheet material ST. Each of the plurality of first skin reflection regions SA1-SA4 indicates the reflectance of the skin with respect to first-wavelength light.

Description

Test chart, image analysis device, image analysis system, image analysis method, and recording medium

[0001] The present disclosure relates to a test chart, an image analysis device, an image analysis system, an image analysis method, and a recording medium.

[0002] For example, Patent Document 1 discloses a method for displaying a digital color face image in which a subject's face is photographed, and the photographed face image is subjected to makeup and hair styling by image processing, and then displayed on a display means.

[0003] In the display method described in Patent Document 1, a color chart with known colorimetric luminance (reflectance) is photographed with a camera under the same environment as the facial image. An illuminance correction coefficient Q1 for the photographing environment is calculated from the RGB values ​​of the color chart image output from the camera to a computer device. The photographed facial image is then imported into the computer device, and illuminance correction is performed by converting the RGB components of each pixel in the entire image to a converted output level for colorimetric luminance using the illuminance correction coefficient Q1. The facial image converted to a converted output level for colorimetric luminance using the illuminance correction coefficient Q1 for the photographing environment is then corrected by the camera to an output level using a pre-adjusted illuminance correction coefficient Q2 that "makes the face (skin color) appear to have a desirable brightness" and output to a display.

[0004] Japanese Patent Application Laid-Open Nos. 2003-222299 and 2003-222299 disclose gray scale test charts.

[0005] Patent Document 2 discloses a test chart that transmits light from a light-emitting section. This test chart is integrally provided with grayscale chart sections 23A and 23B, which are made up of a plurality of sections arranged in parallel that have different levels of light transmittance, and a resolution chart section 24, which is made up of a light and dark striped pattern at a predetermined pitch.

[0006] Japanese Patent Application Laid-Open No. 2003-144992 discloses a test chart in which two patterns, which are the same gradation pattern, are arranged point-symmetrically with respect to the center point of the paper surface.

[0007] Japanese Patent Application Laid-Open No. 2002-10283 Japanese Patent Application Laid-Open No. 07-222206 Japanese Patent Application Laid-Open No. 2001-268363

[0008] The present disclosure aims to improve upon the techniques described in the prior art documents mentioned above.

[0009] According to one aspect of the present disclosure, a test chart is provided, comprising: a sheet material; and a plurality of first skin reflective areas formed on the sheet material, each of the plurality of first skin reflective areas indicating the reflectivity of skin to a first wavelength of light.

[0010] According to one aspect of the present disclosure, there is provided an image analysis device comprising: an image acquisition means for acquiring a chart image obtained by photographing a test chart; and an analysis means for analyzing the chart image, wherein the test chart comprises a sheet material and a plurality of first skin reflective areas formed on the sheet material, each of the plurality of first skin reflective areas indicating the reflectivity of skin with respect to a first wavelength light.

[0011] According to one aspect of the present disclosure, there is provided an image analysis system comprising: a test chart; a camera that photographs the test chart to generate a chart image; a first light that irradiates the test chart with the first wavelength light; and an image analysis device, wherein the test chart comprises: a sheet material; and a plurality of first skin reflective areas formed on the sheet material, each of the plurality of first skin reflective areas indicating the reflectivity of skin with respect to the first wavelength light; and the image analysis device comprises: an image acquisition means that acquires a chart image obtained by photographing the test chart; and an analysis means that analyzes the chart image.

[0012] According to one aspect of the present disclosure, there is provided an image analysis method including: one or more computers acquiring a chart image obtained by photographing a test chart; and analyzing the chart image; the test chart comprising a sheet material and a plurality of first skin reflective areas formed on the sheet material; and each of the plurality of first skin reflective areas indicating the reflectivity of skin to a first wavelength light.

[0013] According to one aspect of the present disclosure, there is provided a recording medium having recorded thereon a program for causing a computer to acquire a chart image obtained by photographing a test chart and analyze the chart image, the test chart comprising a sheet material and a plurality of first skin reflective areas formed on the sheet material, each of the plurality of first skin reflective areas indicating the reflectivity of skin to a first wavelength light.

[0014] 1 is a diagram showing a test chart according to the first embodiment. FIG. 2 is a diagram showing an example of the configuration of an image analysis system according to the first embodiment. FIG. 3 is a diagram showing an overview of an image analysis device according to the first embodiment. FIG. 4 is a flowchart showing an overview of an image analysis method according to the first embodiment. FIG. 4 is a diagram showing an example of a detailed functional configuration of an image analysis device according to the first embodiment. FIG. 5 is a diagram showing an example of the physical configuration of an image analysis device according to the first embodiment. FIG. 6 is a flowchart showing an example of a detailed image analysis method according to the first embodiment. FIG. 7 is a flowchart showing an example of a detailed analysis process according to the first embodiment. FIG. 8 is a diagram showing an example of a display image when all of the first skin reflection images SAim1 to SAim4 are determined to be good images. FIG. 9 is a diagram showing an example of a display image when only the first skin reflection image SAim1 is determined to be an unsatisfactory image. FIG. 10 is a diagram showing an example of a display image when only the first skin reflection image SAim3 and the first skin reflection image SAim4 are determined to be unsatisfactory images. FIG. 11 is a diagram showing an example of a display image when all of the first skin reflection images SAim1 to SAim4 are determined to be unsatisfactory images. FIG. 10 is a diagram showing an example of a displayed image when only the second skin reflection image SBim1 is determined to be an unsatisfactory image. FIG. 11 is a diagram showing an example of a displayed image when only the second skin reflection image SBim3 and the second skin reflection image SBim4 are determined to be unsatisfactory images. FIG. 12 is a diagram showing an example of a displayed image when all of the second skin reflection images SBim1 to SBim4 are determined to be unsatisfactory images. FIG. 13 is a diagram showing an example of the configuration of an image analysis system according to a third embodiment. FIG. 14 is a diagram showing an example of the functional configuration of an image analysis device according to the third embodiment. FIG. 15 is a flowchart showing an example of an image analysis method according to the third embodiment. FIG. 16 is a diagram showing an example of the configuration of an image analysis system according to a fourth embodiment. FIG. 17 is a flowchart showing an example of an image analysis method according to the fourth embodiment. FIG. 18 is a flowchart showing an example of a detailed example of analysis processing according to the fourth embodiment. FIG. 19 is a diagram showing a first example of a first image area and a second image area when an area specifying condition related to the position where the first light is installed is set.FIG. 10 is a diagram showing a second example of the first image area and the second image area when an area specifying condition related to the position where the first light is installed is set. FIG. 11 is a diagram showing an example of the configuration of a test chart related to embodiment 5. FIG. 12 is a diagram showing an example of the configuration of an image analysis system related to embodiment 5. FIG. 13 is a diagram showing an example of the functional configuration of an image analysis device related to embodiment 5. FIG. 14 is a flowchart showing an example of an image analysis method related to embodiment 5. FIG. 15 is a flowchart showing a detailed example of analysis processing related to embodiment 5. FIG. 16 is a diagram showing a third example of the first image area and the second image area when an area specifying condition related to the position where the first light is installed is set.

[0015] Hereinafter, embodiments of the present disclosure will be described with reference to the drawings. In all drawings, similar components are denoted by similar reference numerals, and descriptions thereof will be omitted where appropriate.

[0016] 1 is a diagram showing a test chart TC1 according to embodiment 1. The test chart TC1 includes a sheet material ST and a plurality of first skin reflective areas SA1 to SA4 formed on the sheet material ST. Each of the plurality of first skin reflective areas SA1 to SA4 indicates the reflectance of skin with respect to first wavelength light.

[0017] This test chart TC1 makes it possible to improve upon the techniques described in the prior art documents mentioned above.

[0018] 2 is a diagram showing an example of the configuration of the image analysis system 100 according to embodiment 1. The image analysis system 100 includes a test chart TC1, a camera 101, a first light 102, and an image analysis device 103.

[0019] The camera 101 captures an image of the test chart TC1 to generate a chart image. The first light 102 irradiates the test chart TC1 with light of a first wavelength.

[0020] FIG. 3 is a diagram showing an overview of the image analysis device 103 according to the first embodiment.

[0021] The image analysis device 103 includes an image acquisition unit 104 that acquires a chart image obtained by photographing the test chart TC1, and an analysis unit 105 that analyzes the chart image.

[0022] This image analysis system 100 makes it possible to obtain an appropriate skin image by photographing using light of a specific wavelength. Furthermore, this image analysis device 103 makes it possible to improve the techniques described in the prior art documents mentioned above.

[0023] FIG. 4 is a flowchart showing an outline of the image analysis method according to the first embodiment.

[0024] The image acquisition unit 104 acquires a chart image by photographing the test chart TC1 (step S101), and the analysis unit 105 analyzes the chart image (step S102).

[0025] This image analysis method makes it possible to improve upon the techniques described in the prior art documents mentioned above.

[0026] Below, detailed examples of the test chart TC1, the image analysis system 100, the image analysis device 103, and the image analysis method according to the first embodiment will be described.

[0027] (Details) Generally, when capturing images for facial recognition and the like, light of a specific wavelength is often irradiated onto the subject. Furthermore, the reflectance of a person's skin to light of a specific wavelength generally varies depending on the person's condition (e.g., physical condition, makeup, etc.), innate characteristics, etc. Therefore, images of various people captured using light of a specific wavelength may have overexposure or underexposure depending on the skin's reflectance to that light, resulting in low-quality images.

[0028] For example, in the technology described in Patent Document 1, an image is corrected using the illuminance correction coefficients Q1 and Q2 as described above. If the image showing the skin (skin image) itself generated by shooting is a low-quality image that includes blown-out highlights and crushed shadows, it may be difficult to obtain an appropriate skin image by shooting using light of a specific wavelength, even if the technology described in Patent Document 1 is used.

[0029] Furthermore, for example, even if the techniques described in Patent Documents 2 and 3 can obtain an image in which a gradation pattern is properly captured, it may be difficult to obtain an appropriate skin image by capturing an image using light of a specific wavelength.

[0030] In view of the above circumstances, an example of an objective of the present disclosure is to provide a test chart, an image analysis device, an image analysis system, an image analysis method, and a recording medium that solve the problem of obtaining an appropriate skin image by photographing using light of a specific wavelength. (Configuration Example of Test Chart TC1) Test chart TC1 is a tool for checking in advance the light environment of a location (photography location) where a person is photographed for purposes such as facial recognition. The light environment refers to an environment related to light (e.g., the distribution of light), and the light that creates the light environment may be various types of light such as natural light or illumination light. Natural light is, for example, sunlight. Illumination light is light used for illumination, and its light source may be, for example, an LED (Light-Emitting Diode), a fluorescent lamp, an incandescent lamp, or the like.

[0031] As shown in FIG. 1, the test chart TC1 includes a sheet material ST and a first area SA that is appropriately set on one main surface of the sheet material ST.

[0032] The sheet material ST is a rectangular sheet, for example, about 200 mm (millimeters) wide and 100 to 300 mm long.

[0033] The sheet material ST is preferably opaque and made of, for example, cardboard, plastic, wood, metal, glass, or a combination of one or more of these. If the material of the sheet material ST is cardboard, plastic, wood, or the like, the sheet material ST will be lightweight, making it easy to carry.

[0034] The shape, dimensions, and material of the sheet material ST are not limited to those described above, and may be changed as appropriate.

[0035] A plurality of first skin reflective areas SA1 to SA4 are formed in the first area SA. Each of the plurality of first skin reflective areas SA1 to SA4 indicates the reflectance of the skin with respect to the first wavelength light (unit: %, for example). The first skin reflective areas SA1 to SA4 are also referred to as color charts, patches, etc. Note that the number of first skin reflective areas is not limited to four, as long as a plurality (i.e., two or more) of first skin reflective areas are formed in the first area SA.

[0036] The first wavelength light is light used to photograph a subject. The wavelength of the first wavelength light is the first wavelength. For example, the first wavelength light is near-infrared light, and in this case, the first wavelength is a specific wavelength selected from the range of 780 to 2500 nm.

[0037] In the example shown in Fig. 1 , the first skin reflective area SA1 is an area corresponding to human skin having a reflectance of A1 for light at the first wavelength. The first skin reflective area SA2 is an area corresponding to human skin having a reflectance of A2 for light at the first wavelength. The first skin reflective area SA3 is an area corresponding to human skin having a reflectance of A3 for light at the first wavelength. The first skin reflective area SA4 is an area corresponding to human skin having a reflectance of A4 for light at the first wavelength.

[0038] The reflectances A1 to A4 are different from one another, and the magnitudes of A1 to A4 according to this embodiment are A1>A2>A3>A4.

[0039] A1 is the maximum reflectance of the skin for the first wavelength light. That is, the first skin reflective area SA1 corresponds to the "first maximum area" that shows the maximum reflectance of the skin for the first wavelength light.

[0040] A4 is the minimum reflectance of the skin for the first wavelength light. That is, the first skin reflective area SA4 corresponds to the "first minimum area" that indicates the minimum reflectance of the skin for the first wavelength light.

[0041] Generally, in an environment where light having a specific wavelength is irradiated onto human skin, the reflectance of the human skin will be a value between the maximum reflectance and the minimum reflectance according to the wavelength of the irradiated light. For example, when the irradiated light is near-infrared light, the maximum reflectance is approximately 70 to 95% and the minimum reflectance is approximately 5 to 30%. The maximum and minimum reflectances of human skin with respect to light having such a specific wavelength (e.g., first wavelength light) can be obtained, for example, by irradiating a large number of people with light having the specific wavelength and measuring the reflectance.

[0042] The plurality of first skin reflective regions SA1 to SA4 may include the first maximum region and the first minimum region, and the number of first skin reflective regions may be changed as appropriate as long as it is two or more.

[0043] There are various methods for manufacturing the test chart TC1, and one example will be described below.

[0044] First, the worker prepares multiple pieces of paper that will form each of the first skin reflective areas SA1-SA4 and attaches each piece of paper to a backing. The multiple pieces of paper are, for example, paper coated with paint that is adjusted to the reflectance of each of the first skin reflective areas SA1-SA4. The paint may be, for example, a matte lacquer-based paint, but is not limited to this.

[0045] Next, the worker prepares a piece of black cardboard the same size as the mount and cuts out the areas corresponding to the multiple pieces of paper attached to the mount (i.e., the multiple first skin reflective areas SA1 to SA4).The worker then attaches this black cardboard to the mount with the multiple pieces of paper attached.The black cardboard preferably has a reflectance of 0 (zero) for near-infrared light, for example.This allows the test chart TC1 to be manufactured.In this example, the sheet material ST is composed of the mount and the black cardboard.

[0046] (Configuration example of image analysis system 100) The camera 101 is a camera for capturing an image of a subject for purposes such as facial recognition. When an image obtained by capturing an image is used for facial recognition, the camera 101 is configured to capture an image of a person's face. In preparation before capturing an image of the subject, the camera 101 captures an image of a test chart TC1 and generates a chart image. Note that the camera 101 may be a near-infrared camera capable of capturing an iris image for iris recognition.

[0047] The first light 102 is a light for irradiating the subject with first wavelength light. When an image obtained by photographing is used for face recognition, the first light 102 is provided to irradiate the person's face with the first wavelength light while the camera 101 is photographing, for example. The first light 102 may irradiate the test chart TC1 with the first wavelength light in advance preparation before the camera 101 photographs the subject.

[0048] The image analysis system 100 may include multiple first lights 102 .

[0049] 5 is a diagram showing a detailed example of the functional configuration of the image analysis device 103 according to embodiment 1. The image analysis device 103 is a device that analyzes a chart image generated by photographing the test chart TC1.

[0050] The image analysis device 103 functionally includes, for example, an image acquisition unit 104 , an analysis unit 105 , a display unit 106 , and a display control unit 107 .

[0051] The image acquisition unit 104 acquires, for example, a chart image generated by the camera 101. The image acquisition unit 104 acquires the image from the camera 101 via, for example, a wired, wireless, or combination thereof communication line.

[0052] The analysis unit 105 analyzes the chart image. Functionally, the analysis unit 105 includes a brightness acquisition unit 108 and a determination unit 109.

[0053] The brightness acquisition unit 108 obtains the brightness of each of the first skin reflection images SAim1 to SAim4. The first skin reflection images SAim1 to SAim4 are image portions that represent the first skin reflection regions SA1 to SA4, respectively, in the chart image.

[0054] The determination unit 109 determines whether each of the first skin reflection images SAim1 to SAim4 is a good image that satisfies a predetermined first determination criterion based on the brightness of each of the first skin reflection images SAim1 to SAim4.

[0055] The first criterion is, for example, that the brightness of the first skin reflection images SAim1 to SAim4 is less than a first threshold value and greater than a second threshold value. The first threshold value is a value greater than the second threshold value.

[0056] The first threshold is a value that is appropriately set to determine whether or not overexposure has occurred. That is, the determination unit 109 determines whether or not overexposure has occurred by comparing the brightness of each of the first skin reflection images SAim1 to SAim4 with the first threshold.

[0057] The second threshold is a value that is appropriately set to determine whether or not black crush has occurred. That is, the determination unit 109 determines whether or not black crush has occurred by comparing the brightness of each of the first skin reflection images SAim1 to SAim4 with the second threshold.

[0058] In this case, for example, the determination unit 109 determines that the first skin reflection images SAim1 to SAim4 that are free of whiteout or blackout are good images, and the determination unit 109 determines that the first skin reflection images SAim1 to SAim4 that are free of whiteout or blackout are not good images.

[0059] The display unit 106 displays various types of information under the control of the display control unit 107. The display control unit 107 displays, for example, the analysis result of the chart image on the display unit 106. In detail, for example, the display control unit 107 generates a display image in which the analysis result of the chart image is superimposed on the chart image, and displays the display image on the display unit 106.

[0060] (Example of Physical Configuration of Image Analysis Device 103) Fig. 6 is a diagram showing an example of the physical configuration of the image analysis device 103 according to embodiment 1. The image analysis device 103 is configured by, for example, a computer.

[0061] The image analysis device 103 includes, for example, a bus 1010 , a processor 1020 , a memory 1030 , a storage device 1040 , a network interface 1050 , an input interface 1060 , and an output interface 1070 .

[0062] The bus 1010 is a data transmission path for transmitting and receiving data among the processor 1020, memory 1030, storage device 1040, network interface 1050, input interface 1060, and output interface 1070. However, the method of connecting the processor 1020 and the like to each other is not limited to bus connection.

[0063] The processor 1020 is implemented as a CPU (Central Processing Unit) or a GPU (Graphics Processing Unit).

[0064] The memory 1030 is a main storage device realized by a RAM (Random Access Memory) or the like.

[0065] The storage device 1040 is an auxiliary storage device realized by a hard disk drive (HDD), a solid state drive (SSD), a memory card, a read only memory (ROM), or the like. The storage device 1040 stores program modules for realizing each function of the image analysis device 103. The processor 1020 reads each of these program modules into the memory 1030 and executes them, thereby realizing each function corresponding to the program module.

[0066] The network interface 1050 is an interface for connecting the image analyzing device 103 to a communication line.

[0067] The input interface 1060 is an interface for the user to input information, and is composed of, for example, a touch panel, a keyboard, a mouse, and the like.

[0068] The output interface 1070 is an interface for presenting information to the user, and is configured, for example, by a liquid crystal panel, an organic EL (Electro-Luminescence) panel, or the like.

[0069] The physical configuration of the image analysis device 103 is not limited to that described here and may be changed as appropriate. The image analysis device 103 may be configured, for example, by a plurality of computers. Furthermore, for example, one or both of the camera 101 and the first light 102 may be configured integrally with the image analysis device 103.

[0070] (Detailed Example of Image Analysis Method According to First Embodiment) Fig. 7 is a flowchart showing a detailed example of the image analysis method according to the first embodiment. The image analysis method is a method for analyzing a chart image generated by photographing a test chart TC1. The image analysis method is started, for example, when the camera 101 photographs the test chart TC1 in response to an instruction from a user. When photographing the test chart TC1, the test chart TC1 is placed, for example, at a location where a subject (for example, the face of a person to be authenticated) is located in face authentication.

[0071] The image acquisition unit 104 acquires a chart image obtained by photographing the test chart TC1 (step S101).

[0072] In detail, for example, the image acquisition unit 104 acquires a chart image from the camera 101 .

[0073] The analysis unit 105 analyzes the chart image (step S102).

[0074] FIG. 8 is a flowchart showing a detailed example of the analysis process (step S102) according to the first embodiment.

[0075] The brightness acquisition unit 108 acquires the brightness of each of the first skin reflection images SAim1 to SAim4 based on the chart image acquired in step S101 (step S102a).

[0076] More specifically, for example, the brightness acquisition unit 108 extracts pixel values ​​of each of the first skin reflection images SAim1 to SAim4 from the chart image acquired in step S101. The brightness acquisition unit 108 calculates the brightness of each of the first skin reflection images SAim1 to SAim4 based on the extracted pixel values.

[0077] The determination unit 109 determines whether each of the first skin reflection images SAim1 to SAim4 is a good image that satisfies a predetermined first determination criterion based on the brightness obtained in step S102a (step S102b).

[0078] The first criterion is, for example, as described above, that the brightness of the first skin reflection images SAim1 to SAim4 is less than the first threshold and greater than the second threshold.

[0079] The determination unit 109 determines that the first skin reflection images SAim1-SAim4 obtained in step S102a with brightness equal to or greater than the first threshold have overexposed highlights and are therefore not good images (NG) because of this. The determination unit 109 determines that the first skin reflection images SAim1-SAim4 obtained in step S102a with brightness equal to or less than the second threshold have underexposed highlights and are therefore not good images (NG) because of this.

[0080] The first skin reflection images SAim1-SAim4, whose brightness values ​​obtained in step S102a are less than the first threshold and greater than the second threshold, are free of overexposure and underexposure. Therefore, the determining unit 109 determines that these first skin reflection images SAim1-SAim4 are good images (OK).

[0081] After executing step S102b, the determination unit 109 returns to the image analysis process.

[0082] Referring again to Fig. 7, the display control unit 107 generates the display images 111a to 111d, displays the display images 111a to 111d on the display unit 106 (step S103), and ends the image analysis process.

[0083] In detail, for example, the display control unit 107 generates display images 111a to 111d based on the chart image acquired in step S101 and the analysis result in step S102. For example, the display control unit 107 generates display images 111a to 111d by superimposing the analysis result in step S102 on the chart image acquired in step S101.

[0084] 9 to 12 are diagrams showing examples of display images 111a to 111d according to this embodiment.

[0085] 9 shows an example of the display image 111a when all of the first skin reflection images SAim1 to SAim4 are determined to be good images. In this case, regardless of the value of the skin reflectance, it is highly likely that a good enough image (e.g., a facial image) for facial recognition or the like can be obtained. Therefore, it can be seen that the intensity of the first wavelength light is appropriate for the lighting environment of the shooting location.

[0086] 10 shows an example of a display image 111b when only the first skin reflection image SAim1 is determined to be an unsatisfactory image. In this case, if the subject's skin has a high reflectance to the first wavelength light, it may not be possible to obtain a satisfactory image (e.g., a facial image) sufficient for performing facial recognition or other similar tasks. Therefore, it can be seen that the first wavelength light may be too strong in the lighting environment of the shooting location.

[0087] 11 shows an example of a display image 111c when only the first skin reflection image SAim3 and the first skin reflection image SAim4 are determined to be poor quality. In this case, if the subject's skin has a low reflectance to the first wavelength light, it may be impossible to obtain a good enough image (e.g., a facial image) for performing facial recognition or the like. Therefore, it can be seen that the first wavelength light may be weak in the lighting environment of the shooting location.

[0088] 12 shows an example of a display image 111d when none of the first skin reflection images SAim1 to SAim4 are determined to be good images. In this case, regardless of the skin reflectance value, it is highly likely that a good enough image (e.g., a facial image) for facial recognition or other purposes cannot be obtained. Therefore, it can be seen that the first wavelength light may be very weak in the lighting environment of the shooting location.

[0089] By performing such image analysis processing, it is possible to determine whether the lighting environment of the shooting location is suitable for taking photographs for purposes such as facial recognition, and if the lighting environment is inappropriate, it is possible to take appropriate measures to make it suitable. Therefore, it is possible to obtain an appropriate skin image by taking a photograph using light of a specific wavelength. Such a skin image can be used for biometric authentication such as facial recognition or iris recognition, and in such cases, it is possible to obtain an appropriate image for biometric authentication, resulting in more accurate biometric authentication.

[0090] (Operations and Effects) As described above, according to this embodiment, the test chart TC1 includes a sheet material ST and a plurality of first skin reflective areas SA1 to SA4 formed on the sheet material ST. Each of the plurality of first skin reflective areas SA1 to SA4 indicates the reflectance of skin with respect to first wavelength light.

[0091] This allows a user to check in advance whether an appropriate image for a particular application can be obtained when a subject is photographed using light of the first wavelength, and if the lighting environment is inappropriate, measures can be taken to make it appropriate. Therefore, it becomes possible to obtain an appropriate skin image when photographing a subject using light of a specific wavelength.

[0092] According to this embodiment, the image analysis device 103 includes an image acquisition unit 104 that acquires a chart image obtained by photographing the test chart TC1, and an analysis unit 105 that analyzes the chart image. The test chart TC1 includes a sheet material ST and a plurality of first skin reflective areas SA1 to SA4 formed on the sheet material ST. Each of the plurality of first skin reflective areas SA1 to SA4 indicates the reflectance of the skin with respect to first wavelength light.

[0093] This allows a user to check in advance whether an appropriate image for a particular application can be obtained when a subject is photographed using light of the first wavelength, and if the lighting environment is inappropriate, measures can be taken to make it appropriate. Therefore, it becomes possible to obtain an appropriate skin image when photographing a subject using light of a specific wavelength.

[0094] According to this embodiment, the image analysis device 103 further includes a display control unit 107. The display control unit 107 generates display images 111a to 111d by superimposing the analysis results of the chart images on the chart images, and causes the display images 111a to 111d to be displayed on the display unit 106.

[0095] This makes it easy to understand whether the lighting environment of the shooting location is such that an appropriate image for the intended purpose can be obtained when a subject is photographed using light of the first wavelength. Therefore, if the lighting environment is inappropriate, it is easy to take measures to make it appropriate. Therefore, it becomes possible to easily obtain an appropriate skin image when photographing using light of a specific wavelength.

[0096] According to this embodiment, the image analysis system 100 includes a test chart TC1, a camera 101, a first light 102, and an image analysis device 103.

[0097] The test chart TC1 includes a sheet material ST and a plurality of first skin reflective areas SA1 to SA4 formed on the sheet material ST. Each of the plurality of first skin reflective areas SA1 to SA4 indicates the reflectance of skin with respect to first wavelength light.

[0098] The camera 101 captures an image of the test chart TC1 to generate a chart image. The first light 102 irradiates the test chart TC1 with light of a first wavelength.

[0099] The image analysis device 103 includes an image acquisition unit 104 that acquires a chart image obtained by photographing the test chart TC1, and an analysis unit 105 that analyzes the chart image.

[0100] This allows a user to check in advance whether an appropriate image for a particular application can be obtained when a subject is photographed using light of the first wavelength, and if the lighting environment is inappropriate, measures can be taken to make it appropriate. Therefore, it becomes possible to obtain an appropriate skin image when photographing a subject using light of a specific wavelength.

[0101] In this embodiment, an example will be described in which the test chart further includes a plurality of second skin reflection regions that indicate the reflectance of skin to second wavelength light. In this embodiment, for the sake of simplicity, explanations that overlap with those in the first embodiment will be omitted as appropriate, and differences from the first embodiment will be mainly described.

[0102] 13 is a diagram showing a test chart TC2 according to embodiment 2. In addition to the sheet material ST and multiple first skin reflective areas SA1 to SA4 similar to those in embodiment 1, test chart TC2 includes multiple second skin reflective areas SB1 to SB4 formed on the sheet material ST. Each of the multiple first skin reflective areas SB1 to SB4 indicates the reflectance of skin for second wavelength light.

[0103] In detail, the test chart TC2 includes a second area SB that is appropriately set on one main surface of the sheet material ST, in addition to the sheet material ST and the first area SA that are the same as those in the first embodiment. That is, the second area SB is set on the same main surface as the main surface on which the first area SA is set.

[0104] A plurality of second skin reflective areas SB1 to SB4 are formed in the second region SB. Each of the plurality of second skin reflective areas SB1 to SB4 indicates the reflectance of the skin for second wavelength light (unit: %, for example). The second skin reflective areas SB1 to SB4 are also referred to as color charts, patches, etc. Note that the number of second skin reflective areas is not limited to four, as long as a plurality (i.e., two or more) of second skin reflective areas are formed in the second region SB.

[0105] The second wavelength light is light used to photograph a subject. The wavelength of the second wavelength light is the second wavelength. For example, the second wavelength light is near-infrared light, and in this case, the second wavelength is a specific wavelength selected from 700 to 2500 nm, similar to the first wavelength. However, the second wavelength is different from the first wavelength.

[0106] 13 , the second skin reflective region SB1 corresponds to human skin having a reflectance of B1 for second wavelength light. The second skin reflective region SB2 corresponds to human skin having a reflectance of B2 for second wavelength light. The second skin reflective region SB3 corresponds to human skin having a reflectance of B3 for second wavelength light. The second skin reflective region SB4 corresponds to human skin having a reflectance of B4 for second wavelength light.

[0107] The reflectances B1 to B4 are different from one another, and the magnitudes of B1 to B4 according to this embodiment are B1>B2>B3>B4.

[0108] B1 is the maximum reflectance of the skin for the second wavelength light. That is, the second skin reflective region SB1 corresponds to a "second maximum region" that shows the maximum reflectance of the skin for the second wavelength light.

[0109] B4 is the minimum reflectance of the skin for the second wavelength light. That is, the second skin reflective region SB4 corresponds to a "second minimum region" that indicates the minimum reflectance of the skin for the second wavelength light.

[0110] The plurality of second skin reflective regions SB1 to SB4 may include the second maximum region and the second minimum region, and the number of second skin reflective regions may be changed as appropriate as long as it is two or more.

[0111] There are various methods for manufacturing the test chart TC2. For example, the test chart TC2 can be manufactured in the same manner as the test chart TC1 according to embodiment 1. That is, when manufacturing the test chart TC2, an operator may prepare a plurality of pieces of paper forming each of the plurality of first skin reflective regions SA1-SA4, as well as a plurality of pieces of paper forming each of the plurality of second skin reflective regions SB1-SB4, and attach each of the pieces of paper to a backing. Then, the operator may prepare a piece of black cardboard the same size as the backing, cut out portions of the pieces of paper corresponding to the plurality of first skin reflective regions SA1-SA4 and the plurality of second skin reflective regions SB1-SB4, and attach the black cardboard to the backing on which the plurality of pieces of paper are attached.

[0112] 14 is a diagram showing an example of the configuration of an image analysis system 200 according to embodiment 2. The image analysis system 200 includes a second light 202 instead of the first light 102 according to embodiment 1. Except for this, the image analysis system 200 may be configured similarly to the image analysis system 100 according to embodiment 1.

[0113] The second light 202 is a light for irradiating the subject with second wavelength light. When an image obtained by photographing is used for face recognition, the second light 202 is provided to irradiate the person's face with second wavelength light while the camera 101 is photographing, for example. The second light 202 may irradiate the test chart TC2 with second wavelength light in advance preparation before the camera 101 photographs the subject.

[0114] The image analysis system 200 may include multiple second lights 202 .

[0115] The image analyzing device 103 according to this embodiment analyzes a chart image generated by capturing a test chart TC2 instead of the test chart TC1 in embodiment 1. Furthermore, the image analyzing device 103 according to this embodiment uses a plurality of second skin reflection images SBim1 to SBim4 instead of the plurality of first skin reflection images SAim1 to SAim4 in embodiment 1. The second skin reflection images SBim1 to SBim4 are image portions in the chart image that respectively represent a plurality of second skin reflection regions SB1 to SB4.

[0116] Except for these, the image analysis device 103 according to this embodiment may be functionally configured similarly to that of embodiment 1. Note that the image analysis device 103 may automatically determine and repeatedly select either the first skin reflection images SAim1 to SAim4 or the second skin reflection images SBim1 to SBim4 to use depending on, for example, the type of light 102, 202, or may repeat the determination in response to a user instruction.

[0117] The image analysis device 103 according to this embodiment may be physically configured in the same manner as in the first embodiment.

[0118] The image analysis method according to this embodiment analyzes a chart image generated by photographing test chart TC2 instead of test chart TC1 in embodiment 1. Furthermore, the image analysis method according to this embodiment may use multiple second skin reflection images SBim1 to SBim4 instead of the multiple first skin reflection images SAim1 to SAim4 in embodiment 1.

[0119] Except for these, the image analysis method according to this embodiment may be the same as that of the first embodiment.

[0120] 15 to 18 are diagrams showing an example of a display image 211 according to this embodiment. Figures 15 to 18 are examples corresponding to Figures 9 to 12 referred to in the first embodiment, respectively.

[0121] 15 shows an example of a display image 211a when all of the second skin reflection images SBim1 to SBim4 are determined to be good images. Referring to the display image 211a, it can be seen that the intensity of the second wavelength light is appropriate in the lighting environment of the shooting location, as described in the first embodiment. FIG. 16 shows an example of a display image 211b when only the second skin reflection image SBim1 is determined to be an unsatisfactory image. Referring to the display image 211b, it can be seen that the second wavelength light may be too strong in the lighting environment of the shooting location, as described in the first embodiment.

[0122] 17 shows an example of a display image 211c in which only the second skin reflection image SBim3 and the second skin reflection image SBim4 are determined to be poor images. Referring to the display image 211c, it can be seen that the second wavelength light may be weak in the lighting environment of the shooting location, as described in the first embodiment.

[0123] 18 shows an example of a display image 211d when none of the second skin reflection images SBim1 to SBim4 are determined to be good images. Referring to the display image 211d, it can be seen that the second wavelength light may be very weak in the lighting environment of the shooting location, as described in the first embodiment.

[0124] According to this embodiment, the test chart TC2 further includes a plurality of second skin reflection areas SB1 to SB4 formed on the sheet material ST. Each of the second skin reflection areas SB1 to SB4 indicates the reflectance of skin with respect to second wavelength light.

[0125] As a result, whether the image analysis system 100 or 200 uses first wavelength light or second wavelength light, when photographing a subject, it is possible to check in advance whether an appropriate image for the intended purpose can be obtained, and if the lighting environment is inappropriate, it is possible to take appropriate measures. Therefore, it is possible to obtain appropriate skin images by photographing using light of multiple specific wavelengths.

[0126] According to this embodiment, the multiple first skin reflective areas SA1 to SA4 include a first maximum area (first skin reflective area SA1) that shows the maximum reflectance of the skin to the first wavelength light, and a first minimum area (first skin reflective area SA4) that shows the minimum reflectance of the skin to the first wavelength light.

[0127] This allows a check in advance as to whether an appropriate image for a particular application can be obtained when a subject is photographed using light of the first wavelength, regardless of the reflectance of the subject's skin, and if the lighting environment is inappropriate, measures can be taken to make it appropriate. Therefore, it becomes possible to obtain an appropriate skin image when photographing a subject using light of a specific wavelength.

[0128] The multiple second skin reflective areas SB1 to SB4 include a second maximum area (second skin reflective area SB1) that shows the maximum reflectance of the skin to the second wavelength light, and a second minimum area (second skin reflective area SB4) that shows the minimum reflectance of the skin to the second wavelength light.

[0129] This allows a check in advance as to whether an appropriate image for a particular application can be obtained when a subject is photographed using light of the second wavelength, regardless of the reflectance of the subject's skin, and if the lighting environment is inappropriate, measures can be taken to make it appropriate. Therefore, appropriate skin images can be obtained when photographing a subject using light of a plurality of specific wavelengths.

[0130] According to this embodiment, the first wavelength light is near-infrared light.

[0131] This allows you to check in advance whether an appropriate image for the intended purpose can be obtained when photographing a subject using near-infrared light, and if the lighting environment is inappropriate, take appropriate measures to make it appropriate.As a result, it becomes possible to obtain appropriate skin images when photographing using near-infrared light.

[0132] According to this embodiment, the second wavelength light is also near-infrared light.

[0133] This makes it possible to check in advance whether an appropriate image for a particular application can be obtained when a subject is photographed using near-infrared light having one of a plurality of wavelengths, and to take appropriate measures if the lighting environment is inappropriate. Therefore, it becomes possible to obtain an appropriate skin image when photographing a subject using near-infrared light having one of a plurality of wavelengths.

[0134] <Embodiment 3> In this embodiment, a first example will be described in which an image analysis device adjusts a predetermined target device based on the results of analyzing a chart image. In this embodiment, an example will be described in which such an image analysis device is applied in place of the image analysis device 103 included in the image analysis system 100 according to embodiment 1. Therefore, in this embodiment, explanations that overlap with embodiment 1 will be omitted as appropriate, and differences from embodiment 1 will be mainly described.

[0135] The image analysis device 303 described in this embodiment may be applied in place of the image analysis device 103 included in the image analysis system 200 according to the second embodiment.

[0136] 19 is a diagram showing an example of the configuration of an image analysis system 300 according to embodiment 3. The image analysis system 300 includes an image analysis device 303 instead of the image analysis device 103. Except for this point, the image analysis system 300 may be configured similarly to the image analysis system 100 according to embodiment 1.

[0137] 20 is a diagram showing an example of the functional configuration of an image analysis device 303 according to embodiment 3. The image analysis device 303 includes the same image acquisition unit 104 as in embodiment 1, an analysis unit 305 that replaces the analysis unit 105 according to embodiment 1, and an adjustment unit 311.

[0138] The analysis unit 305 analyzes the chart image in the same manner as the analysis unit 105 according to embodiment 1. The analysis unit 305 according to this embodiment obtains the brightness of each of the plurality of first skin reflection images SAim1 to SAim4.

[0139] The adjustment unit 311 adjusts a predetermined target device based on the result of analyzing the chart image.

[0140] Here, the target devices include, for example, at least one of devices used for shooting and devices that affect the lighting environment of the shooting location. The devices used for shooting include, for example, at least one of a camera 101, a first light 102 that is lighting for shooting, etc. If the shooting location is indoors, the devices that affect the lighting environment of the shooting location include, for example, at least one of lighting devices such as an indoor light that illuminates the shooting location, and devices that operate lighting adjustment devices such as curtains and blinds that adjust the amount of light coming in from windows.

[0141] If the target device includes the camera 101, the adjustment unit 311 may adjust the shooting conditions (aperture value, shutter speed, etc.) of the camera 101. If the target device includes the first light 102, the adjustment unit 311 may adjust, for example, whether the first light 102 is turned on or off, and the brightness when turned on. If there are multiple first lights 102, the adjustment unit 311 may adjust whether each of the first lights 102 is turned on or off, and the brightness when turned on, etc.

[0142] If the target device includes one or more lighting devices, the adjustment unit 311 may adjust the on / off status of each of the lighting devices, the brightness when turned on, etc. If the target device includes a device that operates a light adjustment device, the adjustment unit 311 may adjust the amount of light entering through the window by operating the light adjustment device.

[0143] The adjustment unit 311 in this embodiment adjusts the target device so that the brightness of the multiple first skin reflection images SAim1 to SAim4 is less than or equal to the brightness of the first maximum image and greater than or equal to the brightness of the first minimum image.

[0144] The first largest image is an image showing the first largest area (first skin reflection area SA1) in the chart image, which is the first skin reflection image SAim1 in this embodiment. The first smallest image is an image showing the first smallest area (first skin reflection area SA4) in the chart image, which is the first skin reflection image SAim4 in this embodiment.

[0145] The image analysis device 303 according to this embodiment may be physically configured in the same manner as the image analysis device 103 according to the first embodiment.

[0146] (Example of Image Analysis Method According to Third Embodiment) FIG. 21 is a flowchart showing an example of an image analysis method according to the third embodiment.

[0147] When step S101, which is the same as in the first embodiment, is executed, the analysis unit 305 analyzes the chart image (step S302).

[0148] In this embodiment, in step S302, the analysis unit 305 obtains the brightness of each of the plurality of first skin reflection images SAim1 to SAim4.

[0149] The adjustment unit 311 adjusts the predetermined target device based on the result of analyzing the chart image in step S302 (step S304), and ends the image analysis process.

[0150] In detail, for example, in step S304, the adjustment unit 311 adjusts the target device so that the brightness of the multiple first skin reflection images SAim1 to SAim4 is less than or equal to the brightness of the first maximum image and greater than or equal to the brightness of the first minimum image.

[0151] As described in the first embodiment, the reflectances A1 to A4 of the first skin reflection regions SA1 to SA4 have the relationship A1 > A2 > A3 > A4. Therefore, when the lighting environment at the shooting location is appropriate, the brightness of the multiple first skin reflection images SAim1 to SAim4 is as follows: brightness of first skin reflection image SAim1 > brightness of first skin reflection image SAim2 > brightness of first skin reflection image SAim3 > brightness of first skin reflection image SAim4. In other words, at least the brightness of the multiple first skin reflection images SAim1 to SAim4 is equal to or less than the brightness of the first maximum image and equal to or greater than the brightness of the first minimum image.

[0152] In the image analysis process according to this embodiment, the target device is adjusted so that the brightness of the multiple first skin reflection images SAim1 to SAim4 is equal to or less than the brightness of the first largest image (first skin reflection image SAim1) and equal to or greater than the brightness of the first smallest image (first skin reflection image SAim4). This allows adjustments to be made to the appropriate lighting environment at the shooting location. Therefore, it is possible to obtain appropriate skin images by shooting using light of a specific wavelength.

[0153] (Operations and Effects) According to this embodiment, image analysis device 303 further includes adjustment unit 311 that adjusts a predetermined target device based on the analysis results of the chart image. Analysis unit 305 determines the brightness of multiple first skin reflection images SAim1-SAim4, each representing a multiple first skin reflection area SA1-SA4. Adjustment unit 311 adjusts the target device so that the brightness of the multiple first skin reflection images SAim1-SAim4 is equal to or less than the brightness of the first maximum image (first skin reflection image SAim1) representing the first maximum area, and equal to or greater than the brightness of the first minimum image (first skin reflection image SAim4) representing the first minimum area.

[0154] This allows the lighting environment of the shooting location to be adjusted appropriately, making it possible to obtain an appropriate skin image by shooting using light of a specific wavelength.

[0155] Fourth Embodiment In this embodiment, a second example will be described in which an image analysis device adjusts a predetermined target device based on the results of analyzing a chart image. In this embodiment, an example will be described in which such an image analysis device is applied in place of the image analysis device 103 included in the image analysis system 100 according to the first embodiment. Therefore, in this embodiment, explanations that overlap with those in the first embodiment will be omitted as appropriate, and differences from the first embodiment will be mainly described.

[0156] The image analysis device 403 described in this embodiment may be applied in place of the image analysis device 103 included in the image analysis system 200 according to the second embodiment.

[0157] 22 is a diagram showing an example of the configuration of an image analysis system 400 according to embodiment 4. The image analysis system 400 includes an image analysis device 403 instead of the image analysis device 103. Except for this point, the image analysis system 400 may be configured similarly to the image analysis system 100 according to embodiment 1.

[0158] 23 is a diagram illustrating an example of the functional configuration of an image analysis device 403 according to embodiment 4. The image analysis device 403 includes the same image acquisition unit 104 as in embodiment 1, an analysis unit 405 that replaces the analysis unit 105 according to embodiment 1, and an adjustment unit 411.

[0159] The analysis unit 405 analyzes the chart image in the same manner as the analysis unit 105 according to the first embodiment. The analysis unit 405 according to the present embodiment divides the chart image into a plurality of regions, and estimates the lighting environment at the location where the test chart was photographed based on each region.

[0160] In detail, for example, the analysis unit 405 includes a region identification unit 412 and an estimation unit 413 .

[0161] The region specifying unit 412 specifies a first image region and a second image region in the chart image based on predetermined region specifying conditions.

[0162] The area specifying conditions are conditions for specifying, from the chart image, a plurality of image areas to be used for estimating the lighting environment at the shooting location. The area specifying conditions are determined in relation to at least one of the lighting provided for shooting, the positions of one or more lighting devices provided at the shooting location, and the ambient light at the shooting location.

[0163] The lighting provided for shooting is, for example, the first light 102 according to this embodiment. The one or more lighting devices provided at the shooting location are, for example, an interior light that illuminates the shooting location if the shooting location is indoors. The ambient light at the shooting location is, for example, sunlight entering the room through a window if the shooting location is indoors. Since the sunlight entering the room through a window may vary depending on the time of day, the region identification condition may include the time of day, and may also include, for example, conditions for identifying multiple image regions that differ depending on the time of day.

[0164] The estimation unit 413 estimates the lighting environment at the location where the test chart TC1 was photographed, based on each of the first image area and the second image area.

[0165] In more detail, for example, the estimation unit 413 estimates whether each of the first and second light environments is good or not in light of a predetermined second determination criterion. The first light environment is a light environment corresponding to the first image region. The second light environment is a light environment corresponding to the second image region.

[0166] The second criterion is a criterion for determining whether the lighting environment is good. The second criterion includes, for example, a range of image brightness corresponding to a good lighting environment. If the brightness of an image area is within the range defined by the second criterion, the estimation unit 413 may estimate that the lighting environment corresponding to the image area is good. If the brightness of an image area is outside the range defined by the second criterion, the estimation unit 413 may estimate that the lighting environment corresponding to the image area is not good.

[0167] For example, when determining whether a lighting environment is one that will cause crushed shadows or blown-out highlights in a chart image, the second criterion may be defined using a first threshold and a second threshold similar to the first criterion, in which case the second criterion may be that the brightness of the image area is less than the first threshold and greater than the second threshold.

[0168] The adjustment unit 411 adjusts a predetermined target device based on the result of analyzing the chart image, similar to the adjustment unit 311 according to the third embodiment. The adjustment unit 411 according to the present embodiment adjusts the target device based on the light environment estimated by the estimation unit 413.

[0169] The image analysis device 403 according to this embodiment may be physically configured in the same manner as the image analysis device 103 according to the first embodiment.

[0170] (Example of Image Analysis Method According to Fourth Embodiment) FIG. 24 is a flowchart showing an example of an image analysis method according to the fourth embodiment.

[0171] When step S101 similar to that of the first embodiment is executed, the analysis unit 405 analyzes the chart image (step S402).

[0172] FIG. 25 is a flowchart showing a detailed example of the analysis process (step S402) according to the fourth embodiment.

[0173] The region specifying unit 412 specifies a first image region and a second image region in the chart image based on predetermined region specifying conditions (step S402a).

[0174] Fig. 26 is a diagram showing a first example of the first image area and the second image area when an area specifying condition is set related to the position where the first light 102 is installed. Fig. 26 shows an example of the first image area and the second image area when the first light 102 irradiates the first wavelength light from the right side of the test chart TC1.

[0175] Fig. 27 is a diagram showing a second example of the first image area and the second image area when an area specifying condition is set related to the position where the first light 102 is installed. Fig. 27 shows an example of the first image area and the second image area when the first light 102 irradiates the test chart TC1 with first wavelength light from the upper right corner.

[0176] 26 and 27 , the region specifying condition includes, for example, setting a band-shaped region of a predetermined width that passes through approximately the center of the chart image and is approximately perpendicular to the direction in which the first light 102 emits the first wavelength light. The region specifying condition also includes, for example, specifying a first image region and a second image region on opposite sides of the band-shaped region.

[0177] In the examples of FIGS. 26 and 27, the first image area and the second image area are partially different from each other, but the first image area and the second image area may be entirely different from each other.

[0178] Referring again to Fig. 25, the estimation unit 413 estimates the lighting environment at the location where the test chart TC1 was photographed based on the first image area and the second image area identified in step S402a (step S402b), and then returns to the image analysis process.

[0179] In more detail, for example, the estimation unit 413 calculates the brightness of each of the first image region and the second image region identified in step S402a. The estimation unit 413 estimates the lighting environment at the location where the test chart TC1 was captured based on the brightness of each of the first image region and the second image region and the second determination criterion.

[0180] If the second criterion is that the brightness of the image region is less than the first threshold and greater than the second threshold, the estimation unit 413 determines whether the brightness of each of the first image region and the second image region is less than the first threshold and greater than the second threshold.

[0181] For example, if the brightness of the first image region is less than the first threshold and greater than the second threshold, the estimation unit 413 determines that there is a low possibility of whiteout, blackout, or the like occurring in the first image region, and therefore estimates that the first light environment corresponding to the first image region is good.

[0182] Furthermore, for example, if the brightness of the first image region is equal to or greater than a first threshold value, or if the brightness of the first image region is equal to or less than a second threshold value, it is highly likely that blown-out highlights, crushed shadows, etc. have occurred in the first image region, and therefore the estimation unit 413 estimates that the first light environment corresponding to the first image region is not good.

[0183] The estimation unit 413 also estimates whether the second light environment corresponding to the second image area is good or not based on the brightness of the second image area and the second judgment criterion, similar to the first light environment described above.

[0184] Referring again to Fig. 24, the adjustment unit 411 adjusts the predetermined target device based on the result of analyzing the chart image in step S402 (step S403).

[0185] The adjustment unit 411 according to this embodiment adjusts the target device based on the light environment estimated in step S402. This adjustment process (step S403) may be performed in various ways, examples of which will be described below.

[0186] (Example 1 of adjustment process related to embodiment 4) In detail, for example, it is assumed that one of the first and second light environments is estimated to be good, and the other of the first and second light environments is estimated to be bad. Specifically, it is assumed that the first light environment is bad and the second light environment is good, based on the first image area and the second image area illustrated in Fig. 26 .

[0187] In this case, the adjustment unit 411 may apply the operating conditions of the target device associated with the second light environment, which is one of the light environments, to the operating conditions of the target device associated with the first light environment, which is the other light environment.

[0188] Here, the target device may be set in advance to be associated with the first light environment and the second light environment. For example, if the target device is a lighting device such as an indoor light, the lighting device located to the left of the test chart TC1 may be associated with the first light environment, and the lighting device located to the right of the test chart TC1 may be associated with the second light environment.

[0189] This makes it possible to make the first light environment closer to the second light environment, thereby making the first light environment a good environment.

[0190] (Example 2 of Adjustment Process According to Embodiment 4) In detail, for example, it is assumed that one of the first and second light environments is estimated to be good, and the other of the first and second light environments is estimated to be bad. Specifically, it is assumed that the first light environment is bad and the second light environment is good, based on the first image area and the second image area illustrated in Fig. 26 .

[0191] In this case, the adjustment unit 411 may adjust the target device so that the first light environment, which is the other light environment, approaches the second light environment, which is one of the light environments. The target device may be set in advance in association with the first light environment and the second light environment, as in the above-described example 1. For example, the adjustment unit 411 may gradually adjust the target device associated with either or both of the first light environment and the second light environment so that the first light environment, which is the other light environment, approaches the second light environment, which is one of the light environments.

[0192] This makes it possible to make the first light environment closer to the second light environment, thereby making the first light environment a good environment.

[0193] In both examples 1 and 2 of the adjustment process, if multiple first lights 102 are provided to illuminate the test chart TC1 from different directions, some or all of the target device may be multiple first lights 102.

[0194] (Actions and Effects) According to this embodiment, the image analysis device 403 further includes an adjustment unit 411 that adjusts a predetermined target device based on the analysis results of the chart image. The analysis unit 405 includes an area identification unit 412 and an estimation unit 413. The area identification unit 412 identifies a first image area and a second image area of ​​the chart image based on predetermined area identification conditions. The estimation unit 413 estimates the lighting environment at the location where the test chart TC1 was captured based on each of the first image area and the second image area. The adjustment unit 411 adjusts the target device based on the estimated lighting environment.

[0195] This allows the target device to be adjusted to improve the lighting environment corresponding to each of the first and second image regions, thereby enabling appropriate skin images to be obtained by photographing using light of a specific wavelength.

[0196] According to this embodiment, the area specification conditions are determined in relation to at least one of the lighting provided for photography, the positions of one or more lighting devices provided at the photography location, and the ambient light at the photography location.

[0197] This allows the first and second image regions to be identified according to the shooting environment, the light environment corresponding to each image region to be evaluated, and if the light environment is inappropriate, measures can be taken to make it appropriate. Therefore, it is possible to efficiently obtain appropriate skin images by shooting using light of a specific wavelength.

[0198] According to this embodiment, the estimation unit 413 estimates whether each of the first light environment corresponding to the first image area and the second light environment corresponding to the second image area is good or not, based on a predetermined determination criterion (second determination criterion). When one of the first light environment and the second light environment is estimated to be good and the other light environment is estimated to be bad, the adjustment unit 411 applies the operating conditions of the target device associated with one light environment to the operating conditions of the target device associated with the other light environment.

[0199] This allows the first light environment to be closer to the second light environment, making the first light environment a better environment. For example, if there are multiple lighting devices as target devices, the effort required to adjust each of the lighting devices can be reduced. Therefore, it becomes possible to efficiently obtain appropriate skin images by capturing images using light of a specific wavelength.

[0200] According to this embodiment, the estimation unit 413 estimates whether a first light environment corresponding to a first image area and a second light environment corresponding to a second image area are each good or bad, based on a predetermined determination criterion (second determination criterion). When one of the first light environment and the second light environment is estimated to be good and the other light environment is estimated to be bad, the adjustment unit 411 adjusts the target device so that the other light environment approaches the one light environment.

[0201] This allows the first light environment to be closer to the second light environment, making the first light environment a better environment. For example, if there are multiple lighting devices as target devices, the effort required to adjust each of the lighting devices can be reduced. Therefore, it becomes possible to efficiently obtain appropriate skin images by capturing images using light of a specific wavelength.

[0202] Fifth Embodiment In this embodiment, an example will be described in which a test chart includes a plurality of gray areas for evaluating the dynamic range of a chart image, where the plurality of gray areas includes a plurality of first gray areas and a plurality of second gray areas.

[0203] In this embodiment, an example will be described in which such a test chart is applied in place of the test chart TC1 included in the image analysis system 100 according to embodiment 1. Therefore, in this embodiment, explanations that overlap with embodiment 1 will be omitted as appropriate, and differences from embodiment 1 will be mainly described.

[0204] The test chart TC3 described in this embodiment may be used in place of the test charts TC1 and TC2 included in the image analysis systems 200, 300, and 400 according to embodiments other than embodiment 1. The multiple gray areas may include only one of the first gray areas GLA1 to GLA10 and the second gray areas GLB1 to GLB10.

[0205] 28 is a diagram showing an example of the configuration of test chart TC3 according to embodiment 5. Test chart TC3 includes a sheet material ST and a plurality of first skin reflective areas SA1 to SA4 similar to those in embodiment 1, and a plurality of second skin reflective areas SB1 to SB4 similar to those in embodiment 2. Furthermore, test chart TC3 includes a plurality of first gray areas GLA1 to GLA10 and a plurality of second gray areas GLB1 to GLB10.

[0206] In detail, the test chart TC3 includes the sheet material ST and the first area SA similar to those in the first embodiment, the second area SB similar to those in the second embodiment, and a third area GLA and a fourth area GLB appropriately set on one main surface of the sheet material ST. That is, the third area GLA and the fourth area GLB are set on the same main surface as the one main surface on which the first area SA and the second area SB are set.

[0207] A plurality of first gray areas GLA1 to GLA10 are formed in the third area GLA. Each of the plurality of first gray areas GLA1 to GLA10 indicates the reflectance (unit: %, for example) of the skin for the first wavelength light and the second wavelength light. The first gray areas GLA1 to GLA10 are also referred to as color charts, patches, etc.

[0208] The first gray areas GLA1 to GLA10 are arranged in order of darkness so that the darkness they represent changes at a constant rate.

[0209] In the example shown in Fig. 28, the first gray areas GLA1 to GLA10 are gray areas with reflectances of 90%, 80%, 70%, 60%, 50%, 40%, 30%, 20%, 10%, and 5%, respectively. The first gray areas GLA1 to GLA10 are arranged at equal intervals in the horizontal direction so that they become gradually darker (i.e., the reflectance decreases) from left to right in Fig. 28.

[0210] Note that the difference in darkness between GLA9 and GLA10 is 5%, which is different from the difference in darkness between the other adjacent first gray areas GLA1 to GLA9 (10%). However, this is due to manufacturing constraints, and this is an example of the first gray area GLA10 having a reflectance close to 0%.

[0211] A plurality of second gray areas GLB1 to GLB10 are formed in the fourth area GLB. Each of the plurality of second gray areas GLB1 to GLB10 indicates the reflectance (unit: %, for example) of the skin for the first wavelength light and the second wavelength light. The second gray areas GLB1 to GLB10 are also referred to as color charts or patches.

[0212] The second gray areas GLB1 to GLB10 exhibit darkness levels corresponding to the darkness levels exhibited by each of the plurality of first gray areas GLA1 to GLA10. Therefore, the plurality of first gray areas GLA1 to GLA10 and the plurality of second gray areas GLB1 to GLB10 include multiple combinations of first gray areas and second gray areas exhibiting the same darkness levels (e.g., GLA1 and GLB1, GLA2 and GLB2, GLA3 and GLB3, etc.).

[0213] The first gray areas GLA1 to GLA10 and the second gray areas GLB1 to GLB10, which show corresponding shades, are formed in positions symmetrical with respect to a common point C. For example, GLA1 and GLB1, GLA2 and GLB2, GLA3 and GLB3, etc. are formed in positions equidistant from each other in opposite directions with respect to the common point C. As a result, the second gray areas GLB1 to GLB10 are arranged in the opposite order of shade to the multiple first gray areas GLA1 to GLA10, so that the shades they show change at a constant rate.

[0214] Point C is, for example, the center of the sheet material ST, but is not limited to this.

[0215] In the example shown in FIG. 28, the second gray areas GLB1 to GLB10 are gray areas with reflectances of 90%, 80%, 70%, 60%, 50%, 40%, 30%, 20%, 10%, and 5%, respectively.

[0216] The first gray areas GLA1 to GLA10 are arranged at equal intervals in the horizontal direction so that they become gradually darker (reflectance decreases) from right to left in Fig. 28. In this way, the first gray areas GLA1 to GLA10 are arranged in the horizontal direction in the opposite order of darkness.

[0217] The plurality of first skin reflective areas SA1 to SA4 and SB1 to SB4 and the plurality of second skin reflective areas SB1 to SB4 are formed between the plurality of first gray areas GLA1 to GLA10 and the plurality of second gray areas GLB1 to GLB10.

[0218] There are various methods for manufacturing the test chart TC3. For example, the test chart TC3 can be manufactured in the same manner as the test charts TC1 and TC2 according to the first or second embodiment. That is, when manufacturing the test chart TC3, an operator prepares a plurality of pieces of paper that form the plurality of first skin reflective areas SA1-SA4 and the plurality of second skin reflective areas SB1-SB4. In addition, the operator prepares a plurality of pieces of paper that form the plurality of first gray areas GLA1-GLA10 and the plurality of second gray areas GLB1-GLB10. The operator then prepares a piece of black cardboard the same size as the mount and cuts out the portions of the pieces of paper that correspond to the plurality of first skin reflective areas SA1-SA4, the plurality of second skin reflective areas SB1-SB4, the plurality of first gray areas GLA1-GLA10, and the plurality of second gray areas GLB1-GLB10) attached to the mount. The worker may then attach the black cardboard to the backing sheet on which the multiple pieces of paper are attached. The multiple pieces of paper that form the first gray areas GLA1 to GLA10 and the second gray areas GLB1 to GLB10 may be coated with, for example, paint that provides a substantially constant reflectance to near-infrared light that includes the first wavelength light and the second wavelength light.

[0219] 29 is a diagram showing an example of the configuration of an image analysis system 500 according to embodiment 5. The image analysis system 500 includes an image analysis device 503 instead of the image analysis device 103 according to embodiment 1. Except for this point, the image analysis system 500 may be configured similarly to the image analysis system 100 according to embodiment 1.

[0220] Since the test chart TC3 includes a plurality of second skin reflection areas SB1 to SB4, the image analysis system 500 may include the second light 202 according to the second embodiment instead of the first light 102.

[0221] 30 is a diagram illustrating an example of the functional configuration of an image analysis device 503 according to embodiment 5. The image analysis device 503 functionally includes, for example, the image acquisition unit 104, an analysis unit 505, and an adjustment unit 511, which are similar to those in embodiment 1.

[0222] The analysis unit 505 analyzes the chart image in the same manner as in the first embodiment. The analysis unit 105 functionally includes the region identification unit 412 and the estimation unit 513, which are the same as those in the fourth embodiment.

[0223] The estimation unit 513 estimates the lighting environment at the location where the test chart TC3 was photographed, based on each of the first image area and the second image area.

[0224] In more detail, for example, the estimation unit 413 estimates whether the lighting environment includes oblique light based on the brightness of a group of grayscale images included in at least one of the first image region and the second image region. The group of grayscale images is an image that shows each of a plurality of first gray regions and a plurality of second gray regions in a chart image.

[0225] The estimation unit 413 estimates that the lighting environment includes oblique light when the brightness of the group of gray images is not in accordance with the darkness of the corresponding first gray areas GLA1 to GLA10 and second gray areas GLB1 to GLB10.

[0226] The adjustment unit 511 adjusts a predetermined target device based on the result of analyzing the chart image, similar to the adjustment unit 311 according to the fourth embodiment. The adjustment unit 511 according to the present embodiment adjusts the target device based on the light environment estimated by the estimation unit 513.

[0227] For example, if the estimation unit 513 estimates that the lighting environment includes oblique light, the brightness of the chart image may be uneven due to the oblique light. Therefore, the adjustment unit 511 adjusts the target device so that the brightness of the chart image becomes uniform, for example.

[0228] The image analysis device 503 according to this embodiment may be physically configured in the same manner as the image analysis device 103 according to the first embodiment.

[0229] (Example of Image Analysis Method According to Fifth Embodiment) FIG. 31 is a flowchart showing an example of an image analysis method according to the fifth embodiment.

[0230] When step S101 similar to that of the first embodiment is executed, the analysis unit 505 analyzes the chart image (step S502).

[0231] FIG. 32 is a flowchart showing a detailed example of the analysis process (step S502) according to the fifth embodiment.

[0232] The region specifying unit 412 executes step S402a similar to that in the fourth embodiment.

[0233] Fig. 33 is a diagram showing a third example of the first image area and the second image area when an area specifying condition is set related to the position where the first light 102 is installed. Fig. 33 shows an example of the first image area and the second image area when the first light 102 irradiates the first wavelength light from the upper right of the test chart TC3.

[0234] In the figure, first skin reflection images SAim1 to SAim4 are image portions that represent the first skin reflection areas SA1 to SA4 in the chart image of test chart TC3, as described in embodiment 1. Second skin reflection images SBim1 to SBim4 are image portions that represent the second skin reflection areas SB1 to SB4 in the chart image of test chart TC3.

[0235] In the same figure, first gray images GLAim1 to GLAim10 are image portions that represent the multiple first gray areas GLA1 to GLA10 in the chart image of test chart TC3, respectively. Second gray images GLBim1 to GLBim10 are image portions that represent the multiple second gray areas GLB1 to GLB10 in the chart image of test chart TC3, respectively.

[0236] In test chart TC3, the first gray areas GLA1 to GLA10 and the second gray areas GLB1 to GLB10, which indicate corresponding darknesses, are formed at positions symmetrical with respect to a common point C. Therefore, as shown in Fig. 33, each of the first image area and the second image area includes an image of the darkest gray area and an image of the lightest gray area among the plurality of first gray areas GLA1 to GLA10 and the plurality of second gray areas GLB1 to GLB10.

[0237] The images of the darkest gray areas are the image of the first gray area GLA1 (first gray image GLAim10) and the image of the second gray area GLB1 (second gray image GLBim10). The images of the lightest gray areas are the image of the first gray area GLA10 (first gray image GLAim1) and the image of the second gray area GLB10 (second gray image GLBim1).

[0238] In this embodiment, the first image region includes one image of the darkest gray region (second gray image GLBim10) and one image of the lightest gray region (first gray image GLAim1), while the second image region includes the other image of the darkest gray region (first gray image GLAim10) and the other image of the lightest gray region (second gray image GLBim1).

[0239] Furthermore, in this embodiment, each of the first image area and the second image area includes gray images of the respective densities indicated by the plurality of first gray areas GLA1 to GLA10 and the plurality of second gray areas GLB1 to GLB10.

[0240] That is, the first image area includes first gray images GLAim1 to GLAim3 and second gray images GLBim4 to GLBim10 as images of gray areas with reflectances of 90%, 80%, 70%, 60%, 50%, 40%, 30%, 20%, 10%, and 5%. The second image area includes second gray images GLBim1 to GLBim3 and first gray images GLAim4 to GLAim10 as images of gray areas with reflectances of 90%, 80%, 70%, 60%, 50%, 40%, 30%, 20%, 10%, and 5%.

[0241] Referring again to Fig. 32, the estimation unit 513 estimates the lighting environment at the location where the test chart TC3 was photographed based on the first image area and the second image area identified in step S402a (step S502b), and then returns to the image analysis process.

[0242] The estimation unit 513 according to this embodiment estimates that the lighting environment includes oblique light when the brightness of the group of gray images is not in accordance with the darkness of the corresponding first gray areas GLA1 to GLA10 and second gray areas GLB1 to GLB10.

[0243] For example, the estimation unit 513 estimates whether the lighting environment includes oblique light based on the image of the darkest gray region and the image of the lightest gray region included in each of the first image region and the second image region. In detail, for example, if blown-out highlights or crushed shadows occur in the image of the darkest gray region and the image of the lightest gray region included in only one of the first image region and the second image region, the estimation unit 513 estimates that the lighting environment includes oblique light.

[0244] Further, for example, the estimation unit 513 estimates whether the lighting environment includes oblique light based on whether the difference in brightness between adjacent gray images in each of the first image region and the second image region is constant.

[0245] In this embodiment, since the difference in reflectance between adjacent first gray areas GLA1 to GLA10 is constant as described above, the difference in brightness between adjacent first gray images GLAim1 to GLAim10 will be roughly constant unless there is oblique light. Similarly, since the difference in reflectance between adjacent second gray areas GLB1 to GLB10 is constant as described above, the difference in brightness between adjacent second gray images GLBim1 to GLBim10 will be roughly constant unless there is oblique light.

[0246] Therefore, the estimation unit 513 estimates that the lighting environment includes oblique light when, for example, the difference in brightness between adjacent gray images is not constant in at least one of the first image region and the second image region. The estimation unit 513 estimates that the lighting environment does not include oblique light when, for example, the difference in brightness between adjacent gray images is constant in both the first image region and the second image region.

[0247] Referring again to Fig. 31, the adjustment unit 511 adjusts the predetermined target device based on the result of analyzing the chart image in step S502 (step S503).

[0248] In detail, for example, when it is estimated in step S502 that the lighting environment includes oblique light, the adjustment unit 511 adjusts the target device so that the brightness of the chart image is uniform. For example, the adjustment unit 511 adjusts the target device associated with a bright image region of the first image region and the second image region so as to darken the image region that is bright due to oblique light. Also, for example, the adjustment unit 511 adjusts the target device associated with a dark image region of the first image region and the second image region so as to brighten the image region that is dark due to oblique light.

[0249] More specifically, for example, if it is estimated in step S502 that the lighting environment does not include oblique light, the adjustment unit 511 adjusts the shooting conditions of the camera 101 based on the first grayscale images GLAimage1 to GLAimage10 and the second grayscale images GLBim1 to GLBim10 so as to obtain an appropriate dynamic range that satisfies predetermined conditions.

[0250] In the image analysis process according to this embodiment, when the lighting environment includes oblique light, the target device can be adjusted to reduce the effect of oblique light on the chart image, making it possible to obtain an appropriate skin image by capturing an image using light of a specific wavelength.

[0251] Furthermore, if the lighting environment does not include oblique light, the dynamic range can be adjusted, which also makes it possible to obtain appropriate skin images by photographing using light of a specific wavelength.

[0252] (Operations and Effects) According to this embodiment, the test chart TC3 further includes a plurality of first gray areas GLA1 to GLA10 that are formed side by side on the sheet material ST and that exhibit different shadings.

[0253] As a result, the first grayscale images GLAim1 to GLAim10 can be used to evaluate and adjust the gradation of the camera 101. Furthermore, the first skin reflection images SAim1 to SAim4 or the second skin reflection images SBim1 to SBim4 can be used to evaluate or determine whether a satisfactory human skin image can be obtained that can be used for facial recognition, etc. In other words, a single test chart TC3 can be used to evaluate and adjust the gradation of the camera 101 and evaluate or determine whether a satisfactory human skin image can be obtained. Therefore, it is possible to obtain an appropriate skin image by photographing using light of a specific wavelength more easily than, for example, when separate test charts are used for evaluating the gradation of the camera 101 and the human skin image.

[0254] According to this embodiment, the test chart TC3 is formed on a sheet material ST and further includes a plurality of second gray areas GLB1-GLB10 that exhibit shades corresponding to the shades exhibited by the plurality of first gray areas GLA1-GLA10. The plurality of first gray areas GLA1-GLA10 are arranged in order of shade so that the shades exhibited by each of the first gray areas GLA1-GLA10 vary by a constant difference. The first gray areas and second gray areas that exhibit corresponding shades are formed at positions symmetrical with respect to a common point C.

[0255] This makes it easy to include gray images of the respective densities indicated by the plurality of first gray areas GLA1-GLA10 and the plurality of second gray areas GLB1-GLB10 in each of the first image area and the second image area. Therefore, it becomes easy to estimate whether or not the lighting environment includes oblique light based on whether or not the difference in brightness between adjacent gray images is constant. Therefore, it becomes easy to obtain an appropriate skin image by photographing using light of a specific wavelength.

[0256] According to this embodiment, the plurality of first skin reflective areas SA1 to SA4 and the plurality of second skin reflective areas SB1 to SB4 are formed between the plurality of first gray areas GLA1 to GLA10 and the plurality of second gray areas GLB1 to GLB10.

[0257] This allows the use of a single test chart TC3 to evaluate and adjust the gradation of the camera 101 and to evaluate or determine whether a good image of human skin can be obtained. Therefore, it becomes easier to obtain a good skin image by photographing using light of a specific wavelength than when, for example, separate test charts are used for the gradation of the camera 101 and for evaluating the image of human skin.

[0258] According to this embodiment, the test chart TC3 includes a plurality of first gray areas GLA1-GLA10 and a plurality of second gray areas GLB1-GLB10. The plurality of first gray areas GLA1-GLA10 are formed on a sheet material ST and exhibit different shades. The plurality of second gray areas GLB1-GLB10 are formed on a sheet material ST and exhibit shades corresponding to the shades exhibited by the plurality of first gray areas GLA1-GLA10. The plurality of first gray areas GLA1-GLA10 are arranged in order of shade so that the shades they exhibit vary by a constant difference. The first gray areas and second gray areas exhibiting corresponding shades are formed symmetrically with respect to a common point C.

[0259] Furthermore, the estimation unit 513 estimates that the lighting environment includes oblique light when a group of gray images included in at least one of the first image area and the second image area, out of the plurality of gray images GLAim1 to GLAim10 and GLBim1 to GLBim10, does not have brightness corresponding to the darkness of the corresponding plurality of first gray areas GLA1 to GLA10 and plurality of second gray areas GLB1 to GLB10. The plurality of gray images GLAim1 to GLAim10 and GLBim1 to GLBim10 indicate the plurality of first gray areas GLA1 to GLA10 and the plurality of second gray areas GLB1 to GLB10, respectively, in the chart image.

[0260] This makes it possible to determine whether the lighting environment of the shooting location includes oblique light, and if so, to take appropriate measures. Therefore, it becomes possible to obtain appropriate skin images by shooting using light of a specific wavelength.

[0261] The first image area and the second image area each include an image of the darkest gray area and an image of the lightest gray area among the plurality of first gray areas GLA1 to GLA10 and the plurality of second gray areas GLB1 to GLB10.

[0262] This makes it possible to estimate whether the lighting environment includes oblique light, and if the lighting environment of the shooting location includes oblique light, it is possible to take appropriate measures. Therefore, it becomes possible to obtain an appropriate skin image by shooting using light of a specific wavelength.

[0263] Although the embodiments and modifications of the present disclosure have been described above with reference to the drawings, these are merely examples of the present disclosure, and various configurations other than those described above can also be adopted.

[0264] In addition, although the flowcharts used in the above description show multiple steps (processes) in a sequential order, the order of steps executed in each embodiment is not limited to the order shown. In each embodiment, the order of steps shown in the drawings can be changed as long as it does not cause any problems in terms of content. Furthermore, the above-described embodiments and variations can be combined as long as the content is not contradictory.

[0265] A part or all of the above-described embodiments can be described as, but not limited to, the following supplementary notes.

[0266] 1. A test chart comprising: a sheet material; and a plurality of first skin reflective areas formed on the sheet material, each of the plurality of first skin reflective areas indicating skin reflectivity to a first wavelength light. 2. The test chart described in 1., further comprising a plurality of second skin reflective areas formed on the sheet material, each of the plurality of second skin reflective areas indicating skin reflectivity to a second wavelength light. 3. The test chart described in 2., wherein the plurality of first skin reflective areas include a first maximum area indicating maximum skin reflectivity to the first wavelength light and a first minimum area indicating minimum skin reflectivity to the first wavelength light, and the plurality of second skin reflective areas include a second maximum area indicating maximum skin reflectivity to the second wavelength light and a second minimum area indicating minimum skin reflectivity to the second wavelength light. 4. The test chart described in 2. or 3., wherein each of the first wavelength light and the second wavelength light is near-infrared light. 5. The test chart according to any one of 2. to 4., further comprising a plurality of first gray areas formed side by side on the sheet material and exhibiting different shades. 6. The test chart according to 5., further comprising a plurality of second gray areas formed on the sheet material and exhibiting shades corresponding to the shades exhibited by each of the plurality of first gray areas, the plurality of first gray areas being arranged in order of shade so that the shades exhibited by each first gray area vary by a constant difference, and the first gray areas and the second gray areas exhibiting corresponding shades being formed in symmetrical positions with respect to a common point. 7. The test chart according to 6., wherein the plurality of first skin reflective areas and the plurality of second skin reflective areas are formed between the plurality of first gray areas and the plurality of second gray areas. 8. An image analysis device comprising: an image acquisition means for acquiring a chart image obtained by photographing a test chart; and an analysis means for analyzing the chart image, wherein the test chart comprises: a sheet material; and a plurality of first skin reflective areas formed on the sheet material, each of the plurality of first skin reflective areas indicating a reflectance of skin with respect to a first wavelength light.9. The image analysis device described in 8., further comprising an adjustment means for adjusting a predetermined target device based on the analysis results of the chart image, wherein the analysis means calculates the brightness of a plurality of first skin reflection images indicating each of the plurality of first skin reflection areas, and the adjustment means adjusts the target device so that the brightness of the plurality of first skin reflection images is equal to or less than the brightness of a first maximum image indicating a first maximum area and equal to or greater than the brightness of a first minimum image indicating a first minimum area. 10. The image analysis device described in 8., further comprising an adjustment means for adjusting a predetermined target device based on the analysis results of the chart image, wherein the analysis means includes: area identification means for identifying a first image area and a second image area of ​​the chart image based on predetermined area identification conditions; and estimation means for estimating the lighting environment at the location where the test chart was photographed based on each of the first image area and the second image area, and the adjustment means adjusts the target device based on the estimated lighting environment. 11. The image analysis device described in 10., wherein the area specification condition is determined in relation to at least one of lighting provided for photography, the positions of one or more lighting devices provided at the photography location, and ambient light at the photography location. 12. The image analysis device described in 10. or 11., wherein the estimation means estimates whether a first light environment corresponding to the first image area and a second light environment corresponding to the second image area are each good or bad in light of a predetermined determination criterion, and the adjustment means, when one of the first light environment and the second light environment is estimated to be good and the other light environment is estimated to be bad, applies the operating conditions of the target device associated with the one light environment to the operating conditions of the target device associated with the other light environment.13. The image analysis device according to 10. or 11., wherein the estimation means estimates whether a first light environment corresponding to the first image region and a second light environment corresponding to the second image region are each good or not in light of a predetermined determination criterion, and the adjustment means, when one of the first light environment and the second light environment is estimated to be good and the other light environment is estimated to be bad, adjusts the target device so that the other light environment approaches the one light environment. 10. The image analysis device described in 10., wherein the test chart comprises: a plurality of first gray areas formed on the sheet material and exhibiting different shades; and a plurality of second gray areas formed on the sheet material and exhibiting shades corresponding to shades exhibited by each of the plurality of first gray areas, the plurality of first gray areas being arranged in order of shade so that the shades exhibited by each of the plurality of first gray areas vary by a constant difference, the first gray areas and the second gray areas exhibiting corresponding shades being formed at positions symmetrical with respect to a common point, and the estimation means estimates that the lighting environment includes oblique light when, among a plurality of gray images showing each of the plurality of first gray areas and the plurality of second gray areas in the chart image, a group of gray images included in at least one of the first image area and the second image area does not have a brightness corresponding to the shades of the corresponding plurality of first gray areas and the plurality of second gray areas. 15. Each of the first image area and the second image area includes an image of the darkest gray area and an image of the lightest gray area of ​​the plurality of first gray areas and the plurality of second gray areas. 16. The image analysis device according to any one of 8. to 15., further comprising a display control means for generating a display image in which the analysis result of the chart image is superimposed on the chart image, and for displaying the display image on a display means.17. An image analysis system comprising: a test chart; a camera that photographs the test chart to generate a chart image; a first light that irradiates the test chart with light of a first wavelength; and an image analysis device, wherein the test chart comprises: a sheet material; and a plurality of first skin reflective areas formed on the sheet material, each of the plurality of first skin reflective areas indicating skin reflectivity to light of the first wavelength, and the image analysis device comprises: image acquisition means that acquires a chart image obtained by photographing the test chart; and analysis means that analyzes the chart image. 18. An image analysis method including one or more computers that acquire a chart image obtained by photographing a test chart and analyze the chart image, wherein the test chart comprises: a sheet material; and a plurality of first skin reflective areas formed on the sheet material, each of the plurality of first skin reflective areas indicating skin reflectivity to light of the first wavelength. 19. A recording medium having recorded thereon a program for causing a computer to acquire a chart image obtained by photographing a test chart and analyze the chart image, wherein the test chart comprises a sheet material and a plurality of first skin reflective areas formed on the sheet material, each of the plurality of first skin reflective areas indicating the reflectance of skin with respect to a first wavelength light.

[0267] 100, 200, 300, 400, 500 Image analysis system 101 Camera 102 First light 103, 303, 403, 503 Image analysis device 104 Image acquisition unit 105, 305, 405, 505 Analysis unit 106 Display unit 107 Display control unit 108 Brightness acquisition unit 109 Determination unit 111a to 111d, 211a to 211d Display image 202 Second light 311, 411 Adjustment unit 412 Area identification unit 413, 513 Estimation unit TC1, TC2, TC3 Test chart ST Sheet material SA1 to SA4 First skin reflection area SB1 to SB4 Second skin reflection area SAim1 to SAim4 First skin reflection image SBim1 to SBim4: Second skin reflection image GLA1 to GLA10: First gray area GLB1 to GLB10: Second gray area GLAim1 to GLAim10: First gray image GLBim1 to GLBim10: Second gray image

Claims

1. A sheet material; a plurality of first skin reflective areas formed on the sheet material; Each of the plurality of first skin reflective regions indicates a reflectance of skin with respect to light of a first wavelength. Test chart.

2. Further comprising a plurality of second skin reflective areas formed on the sheet material; Each of the plurality of second skin reflective regions indicates a reflectance of skin with respect to light of a second wavelength. The test chart according to claim 1 .

3. the plurality of first skin reflective regions include a first maximum region that indicates a maximum reflectance of skin with respect to the first wavelength light, and a first minimum region that indicates a minimum reflectance of skin with respect to the first wavelength light, The plurality of second skin reflective regions include a second maximum region that indicates a maximum reflectance of the skin to the second wavelength light, and a second minimum region that indicates a minimum reflectance of the skin to the second wavelength light. The test chart according to claim 2.

4. Each of the first wavelength light and the second wavelength light is near-infrared light.

4. The test chart according to claim 2 or 3.

5. an image acquisition means for acquiring a chart image obtained by photographing a test chart; An analysis means for analyzing the chart image, The test chart is A sheet material; a plurality of first skin reflective areas formed on the sheet material; Each of the plurality of first skin reflective regions indicates a reflectance of skin with respect to light of a first wavelength. Image analysis device.

6. and adjusting means for adjusting a predetermined target device based on a result of the analysis of the chart image. The analyzing means determines brightness of a plurality of first skin reflection images each showing a plurality of first skin reflection regions, The adjustment means adjusts the target device so that the brightness of the plurality of first skin reflection images is equal to or lower than the brightness of a first maximum image indicating a first maximum area and equal to or higher than the brightness of a first minimum image indicating a first minimum area. The image analysis device according to claim 5.

7. and adjusting means for adjusting a predetermined target device based on a result of analyzing the chart image. The analysis means an area specifying means for specifying a first image area and a second image area of ​​the chart image based on a predetermined area specifying condition; an estimation means for estimating a light environment at a location where the test chart is photographed based on each of the first image area and the second image area, The adjustment means adjusts the target device based on the estimated lighting environment. The image analysis device according to claim 5.

8. A test chart and a camera for capturing an image of the test chart to generate a chart image; a first light for irradiating the test chart with light of a first wavelength; An image analysis device, The test chart is A sheet material; a plurality of first skin reflective areas formed on the sheet material; Each of the plurality of first skin reflective regions indicates a reflectance of skin with respect to the first wavelength light, The image analysis device includes: an image acquisition means for acquiring a chart image obtained by photographing the test chart; An analysis means for analyzing the chart image. Image analysis system.

9. One or more computers Acquire a chart image by photographing the test chart, analyzing the chart image; The test chart is A sheet material; a plurality of first skin reflective areas formed on the sheet material; Each of the plurality of first skin reflective regions indicates a reflectance of skin with respect to light of a first wavelength. Image analysis methods.

10. On the computer, Acquire a chart image by photographing the test chart, a program for executing analysis of the chart image, The test chart is A sheet material; a plurality of first skin reflective areas formed on the sheet material; Each of the plurality of first skin reflective regions indicates a reflectance of skin with respect to light of a first wavelength. program.