Imaging apparatus, authentication apparatus, and biological body imaging method

Abstract

Provided is a photographic apparatus, authentication apparatus, and biological body photographing method capable of reducing discomfort caused by visible light. A light source (101) is capable of irradiating visible light and non-visible light as irradiation light. An imaging section (102) captures an irradiation region irradiated with the irradiation light to obtain an image. A processor (311) causes the imaging section (102) to obtain a detection image in a first irradiation mode in which non-visible light is irradiated from the light source (101), and determines whether a biological body is presented in the irradiation region based on the detection image. In a case where the biological body is presented, the processor (311) causes the imaging section (102) to obtain a biological body image in which the biological body is captured as the image in a second irradiation mode in which visible light and non-visible light are irradiated from the light source (101).

Description

TECHNICAL FIELD

[0001] The present application relates to a photographing apparatus, an authentication apparatus, and a biological body photographing method. BACKGROUND

[0002] Biological body authentication techniques using biological body images photographed of biological bodies are attracting attention. In biological body authentication techniques, for example, there is a technique of using a blood vessel image obtained by photographing blood vessels of a finger using a difference in near-infrared light absorption characteristics between hemoglobin in blood vessels and other biological body tissues.

[0003] In Patent Literature 1, a biological body authentication apparatus is disclosed that simultaneously irradiates a biological body with a plurality of lights of different wavelength bands such as infrared light and visible light, and performs biological body authentication using a biological body image photographed using light from the biological body. In this biological body authentication apparatus, the biological body image is separated into light component images corresponding to the plurality of lights irradiated on the biological body, and authentication is performed using each light component image, thereby achieving an improvement in authentication accuracy.

[0004] Patent Literature 1: Japanese Patent Application Publication No. 2020-123068

[0005] In a case where a biological body image is photographed using light including visible light as in the technique described in Patent Literature 1, visible light is irradiated from a light source before a biological body is presented to an irradiation region of the light source, and there is a case where the visible light enters the eyes of an authenticant and people around the authenticant, and the people feel discomfort such as a glare. SUMMARY

[0006] An object of the present application is to provide a photographing apparatus, an authentication apparatus, and a biological body photographing method that can reduce discomfort caused by visible light.

[0007] A photographing apparatus according to one aspect of the present application includes an irradiation section that is capable of irradiating visible light and non-visible light as irradiation light; an imaging section that photographs an irradiation region irradiated with the irradiation light to obtain an image; and a control section that, in a first mode in which the non-visible light is irradiated from the irradiation section, causes the imaging section to obtain a detection image as the image, judges whether or not a biological body is presented in the irradiation region on the basis of the detection image, and in a case where the biological body is presented, causes the imaging section to obtain a biological body image photographed with the biological body as the image in a second mode in which the visible light and the non-visible light are irradiated from the irradiation section.

[0008] EFFECT OF THE INVENTION

[0009] According to the present application, it is possible to reduce discomfort caused by visible light. BRIEF DESCRIPTION OF DRAWINGS

[0010] Figure 1is an explanatory view showing an example of the photographing apparatus relating to Embodiment 1.

[0011] Figure 2 is a block diagram showing a configuration example of the photographing apparatus relating to Embodiment 1.

[0012] Figure 3 is a block diagram showing another configuration example of the photographing apparatus relating to Embodiment 1.

[0013] Figure 4 is a flowchart for explaining an example of the photographing corresponding process of the photographing apparatus relating to Embodiment 1.

[0014] Figure 5 is a flowchart for explaining another example of the photographing corresponding process of the photographing apparatus relating to Embodiment 1.

[0015] Figure 6 is a diagram showing an example of the registration process of the photographing apparatus relating to Embodiment 1.

[0016] Figure 7 is a diagram showing an example of the authentication process of the photographing apparatus relating to Embodiment 1.

[0017] Figure 8 is an explanatory view showing a configuration example of the photographing apparatus relating to Embodiment 2.

[0018] Figure 9 is a diagram for explaining an example of a shadow region corresponding to a shadow projected onto a living body.

[0019] Figure 10 is a diagram showing another configuration example of the photographing apparatus relating to Embodiment 2.

[0020] Figure 11 is a diagram for explaining a finger detection method in a case where a shadow region occurs relating to Embodiment 2.

[0021] Figure 12 is a diagram for explaining an example of brightness saturation.

[0022] Figure 13 is a flowchart for explaining a brightness saturation suppression process of the photographing apparatus relating to Embodiment 3.

[0023] Explanation of Reference Numerals

[0024] 100: main body section; 101: light source; 102: imaging section; 106: data storage; 107: controller; 108: photographing apparatus (authentication apparatus); 130: fingertip presentation plate; 300: light source control section; 310: computer; 311: processor; 312: storage device; 313: input device; 314: output device; 315: communication IF; 800: protrusion configuration. Detailed Implementation

[0025] Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings.

[0026] [Example 1]

[0027] <Example of an authentication system structure>

[0028] Figure 1 This is an explanatory diagram showing a photographic apparatus according to Embodiment 1 of the present invention. Figure 1 The illustrated photographic apparatus 108 includes a main body 100 for capturing images of a living organism and acquiring image data of the organism, and a controller 107 that acts as a control unit for controlling the main body 100. The controller 107 may also have an authentication function for authenticating a living organism based on the image data acquired by the main body 100. When the controller 107 has an authentication function, the photographic apparatus 108 may also be referred to as an authentication apparatus 108. Hereinafter, unless otherwise specified, it will be assumed that the controller 107 has the function of an authentication unit. Furthermore, the main body 100 includes a housing 100A, a light source 101, an imaging unit 102, and a data storage unit 106.

[0029] In this embodiment, the photographic device 108 photographs the fingers of a hand 110 that are displayed (specifically, covered) above the upper panel 100B of the housing 100A, serving as the subject (a living organism). The fingers of the subject are here defined as the index finger 111, middle finger 112, and ring finger 113, but this is not a limitation; the number and type of fingers are not particularly limited. For example, the subject may include at least two of the ten fingers of both hands. Furthermore, the index finger 111, middle finger 112, and ring finger 113 will be referred to simply as fingers 111 to 113 below.

[0030] The housing 100A is disposed (e.g., mounted or placed) on a mounting surface 120. The mounting surface 120 can be a horizontal plane such as a floor, ceiling, or tabletop, a vertical plane such as a wall, or an inclined plane. In this embodiment, the axis orthogonal to the mounting surface 120 is defined as the Z-axis, the direction away from the mounting surface 120 on the Z-axis is defined as the +Z direction, and the direction approaching the mounting surface 120 is defined as the -Z direction. Furthermore, the mounting surface 120 is parallel to the XY plane defined by the X-axis and Y-axis. Additionally, as... Figure 1 As shown, the main body 100 is configured such that the fingers 111 to 113 of the hand 110 are displayed above the upper panel 100B. The X-axis is the length direction of the fingers when the fingers 111 to 113 are displayed, and the Y-axis is the arrangement direction of the fingers 111 to 113.

[0031] The light source 101 is provided inside the case 100A. The light source 101 is an irradiation section that irradiates a plurality of wavelength lights different in waveband as irradiation light toward the upper side (+Z direction) of the upper panel section 100B of the case 100A. Specifically, there are a plurality of light sources 101, and wavelength lights different in waveband are irradiated from each light source 101. In the present embodiment, there are two light sources 101, and in the case where these light sources 101 need to be distinguished, they are referred to as light sources 101-1 and 101-2. Further, the wavelength light includes visible light (for example, blue light or green light) and near-infrared light that is non-visible light. In the present embodiment, the light source 101-1 irradiates visible light, and the light source 101-2 irradiates near-infrared light. In addition, the visible light is used to capture the skin surface of the finger to acquire finger surface image data, and the near-infrared light is used to capture the blood vessels of the finger to acquire finger blood vessel image data. In addition, the light source 101 can simultaneously irradiate a plurality of wavelength lights, or can irradiate them at different timings.

[0032] The imaging section 102 is provided inside the case 100A. The imaging section 102 includes, for example, an imaging element such as a CMOS (Complementary Metal Oxide Semiconductor) image sensor or a CCD (Charge Coupled Device) image sensor. The imaging section 102 is disposed so that the imaging surface of the imaging element opposes the upper panel section 100B of the case 100A, so as to capture an irradiation region irradiated with the irradiation light of the light source 101. Further, in the region of the upper panel section 100B that opposes the imaging section 102, a light-transmitting plate 105 is provided that transmits reflected light of the irradiation light of the light source 101 reflected by the fingers 111 to 113. The light-transmitting plate 105 is composed of, for example, a transparent member such as acrylic or glass. Further, a film that transmits only a specific wavelength light can be attached to the light-transmitting plate 105. Thereby, it is possible to make it difficult to see the state inside the main body section 100 from the outside.

[0033] A first optical filter 103 is provided between the imaging section 102 and the upper panel section 100B of the case 100A, and a second optical filter 104 is provided on the optical path of the irradiation light of the light source 101 of the upper panel section 100B.

[0034] The first optical filter 103 and the second optical filter 104 are bandpass filters that transmit light of the same waveband as the irradiation light from the light source 101. In this case, it is possible to suppress the imaging section 102 from receiving unnecessary light, and to suppress noise from occurring in the biological image data. Further, the first optical filter 103 and the second optical filter 104 can be polarization filters. In this case, it is possible to reduce the specular reflection component of the irradiation light reflected by the skin surface of the fingers 111 to 113 by specular reflection, and to acquire more distinct finger blood vessel image data.

[0035] By the above structure, the irradiation light of the light source 101 is reflected by the fingers 111 to 113 of the hand 110 above the upper panel portion 100B via the second optical filter, and the reflected light is received by the imaging surface of the imaging portion 102 via the light-transmissive panel 105 of the upper panel portion 100B and the first optical filter 103. Further, the light received by the imaging portion 102 is photoelectrically converted and output as image data. The imaging portion 102 is connected to the data storage 106, and the image data photoelectrically converted is stored in the data storage 106.

[0036] The image data includes finger vessel image data indicating the blood vessels of the fingers and finger surface image data indicating the color of the skin surface based on the difference in the light absorption characteristics of the skin tissue such as the melanin and the cutin of the skin surface or the unevenness of the skin surface such as the fingerprint. There is also a case where the finger vessel image data and the finger surface image data are collectively referred to as finger image data.

[0037] The controller 107 is connected to the light source 101 and the data storage 106. The controller 107 controls the light source 101 and the imaging portion 102 so that the main body portion 100 acquires the finger image data in Figure 1 the example.

[0038] The controller 107 has a function as a control portion of controlling the light source 101 and the imaging portion 102 so that the main body portion 100 acquires the finger image data, and a function as an authentication portion of extracting feature data indicating the blood vessels and the fingerprint of the fingers 111 to 113 and the like from the finger image data and performing the biometric authentication of the authenticated person based on the feature data.

[0039] Figure 2 is a block diagram showing a more detailed structure example of the imaging device 108 shown in Figure 1 As shown in Figure 2 , the imaging device 108 has the main body portion 100 and the controller 107 as shown in Figure 1 . Further, the controller 107 has a light source control portion 300 and a computer 310.

[0040] The light source control portion 300 controls the lighting timing of the light source 101, the light amount of the irradiation light, and the like in accordance with the instruction from the computer 310.

[0041] The computer 310 has a processor 311, a storage device 312, an input device 313, an output device 314, and a communication IF (Interface) 315. The processor 311, the storage device 312, the input device 313, the output device 314, and the communication IF 315 are connected to each other via a bus 316.

[0042] The processor 311 reads the program stored in the storage device 312, executes the read program, and controls the main unit 100 and the controller 107 as a whole. The storage device 312 is a non-transitory recording medium that stores various programs that regulate the operation of the processor 311 and the data used by the processor 311. In addition, the storage device 312 is also used as the working area of ​​the processor 311. Furthermore, the storage device 312 is, for example, ROM (Read Only Memory), RAM (Random Access Memory), HDD (Hard Disk Drive), or flash memory.

[0043] The aforementioned program includes, for example, an image processing program, a light source control program, and an authentication program. The image processing program is used to process the image data generated by the camera unit 102. The light source control program is used to control the light source 101. The authentication program is used to authenticate the subject based on the image data. Furthermore, at least some of the functions implemented by each program can also be implemented by dedicated circuitry or the like.

[0044] Input device 313 receives various data from the administrator of imaging device 108, etc. Input device 313 may be, for example, a keyboard, mouse, touchpad, numeric keypad, and scanner. Output device 314 outputs the data. Output device 314 may be, for example, a monitor, printer, and speaker. Communication IF 315 connects to an external device (not shown) and transmits and receives data with it. If controller 107 does not function as an authentication unit, authentication of the person being authenticated can also be performed by an external device connected to communication IF 315. Furthermore, communication IF 315 can also connect to external devices via a communication network such as the Internet.

[0045] Figure 3 Other structural examples of the photographic device 108. Figure 3 The photographic device 108 shown is equipped within the main body 100 with a component consisting of... Figure 2 The structure of computer 310 is shown, and computer 310 does not pass through Figure 2 The light source control unit 300 shown controls the light source 101.

[0046] Figure 4 This is a flowchart illustrating an example of the image capture process performed by the photographic device 108 to obtain biological image data (finger image data).

[0047] First, if the start timing of the start of the photographing is reached (step S401), the processor 311 controls the light source control section 300 to cause the light source 101 to emit light in the first emission mode (step S402). The start timing is, for example, a timing at which the person to be authenticated indicates the start of photographing or authentication, or a timing at which the person to be authenticated approaches the photographing apparatus 108, or the like.

[0048] The first emission mode is a mode for acquiring detection image data for detecting the fingers 111 to 113, and is a mode in which near-infrared light is emitted from the light source 101. In the first emission mode, near-infrared light is emitted in an amount that enables detection of the fingers 111 to 113 that are presented in a non-contact state from the main body 100. As for the visible light, it can not be emitted at all, but in order to notify the person to be authenticated of the authentication state in which the authentication apparatus 108 is performing authentication, it is preferable to emit the visible light in an amount that does not easily cause a glare to the person to be authenticated and people around, even if it is emitted into the eyes. The amount of the visible light is, for example, determined to be smaller than the amount of the near-infrared light, and the difference or the ratio between the amount of the visible light and the amount of the near-infrared light is constant.

[0049] Further, the amounts of the near-infrared light and the visible light can be constant, but the amount of the near-infrared light can also vary depending on the brightness of the environment (the amount of the ambient light) at the time of photographing. For example, the processor 311 makes the amount of the near-infrared light large in a case where the near-infrared light of sunlight is large in the ambient light such as sunlight during the day. Thereby, it is possible to improve the detection accuracy of the fingers 111 to 113. In addition, as for the amount of the ambient light, for example, it is possible to periodically acquire image data that is photographed in a state where no finger is presented, and determine based on the image data, or it is possible to provide a sensor that detects the amount of the ambient light, and acquire from the sensor. Further, it is also possible to make the amount of the visible light vary. For example, it is also possible to make the amount of the visible light increase or decrease with the passage of time. In this case, it is possible to make the person to be authenticated more correctly recognize that it is the authentication state.

[0050] Next, the processor 311 drives the imaging section 102. The imaging section 102 performs photographing to generate image data, and stores the image data in the data memory 106 (step S403). Next, the processor 311 analyzes the image data stored in the data memory 106, and performs a finger detection process for detecting a finger region in which the fingers 111 to 113 are photographed in the image data (step S404).

[0051] The finger detection processing specifically is binarization processing that generates binary image data that distinguishes the image data into a finger region that is a foreground region in which the fingers 111 to 113 are imaged and a background region other than the finger region. Here, it is assumed that the light amount of near-infrared light included in the ambient light is sufficiently smaller than the light amount of near-infrared light included in the irradiation light of the light source 101, and the processor 311 distinguishes a bright region within the image data as the finger region and a darker region as the background region. Note that the bright region is, for example, a region of pixels having a luminance value of a threshold value or more, and the darker region is a region of pixels having a luminance value less than the threshold value. Further, in the present embodiment, in a case where visible light is also irradiated in the first irradiation mode, the processor 311 separates the image data into finger blood vessel image data that is near-infrared light image data and a finger surface image data that is visible light image data, and generates binary image data from the near-infrared light image data.

[0052] Further, the processor 311 determines whether or not the finger is detected on the basis of the binary image data that is a processing result of the finger detection processing, and thereby determines whether or not the finger is presented at an appropriate position of the irradiation region of the light source 101 (step S405). For example, the processor 311 determines whether or not the proportion of the finger region within the image data with respect to the entire region exceeds a prescribed proportion, and determines that the finger is detected in a case where the proportion of the finger region exceeds the prescribed proportion. Further, the processor 311 can also determine whether or not the shape of the contour line that is a boundary line between the finger region and the background region in the binary image data assumes the shape of the finger, and determines that the finger is detected in a case where the shape of the contour line of the finger region assumes the shape of the finger. Note that the shape of the contour line of the finger region assumes the shape of the finger, for example, in a case where the degree of similarity of the shape of the contour line of the finger region to the shape of the finger that is registered in advance shows a prescribed value or more. Further, the shape of the finger can be the shape of the entire finger, or the shape of a part of the finger such as the fingertip and the finger root.

[0053] In a case where the finger is not detected (step S405: No), the processor 311 returns to the processing of step S402. On the other hand, in a case where the finger is detected (step S405: Yes), the processor 311 controls the light source control section 300 to irradiate light from the light source 101 in the second irradiation mode (step S406).

[0054] The second irradiation mode is a mode for acquiring biometric image data (finger image data) used for authentication of an authenticator, and is a mode in which both near-infrared light and visible light are irradiated from the light source 101. In the second irradiation mode, the light amount of the visible light is larger than the light amount of the visible light in the case where the irradiation of the visible light is performed in the first irradiation mode. The light amounts of the infrared light and the visible light are set so that the finger image data becomes an appropriate brightness in a state where the near-infrared light and the visible light are simultaneously irradiated on the fingers 111 to 113. At this time, the light amounts of the infrared light and the visible light are set respectively. For example, in a case where the imaging section 102 includes a plurality of sensors having different wavelength sensitivity characteristics like a camera, the imaging section 102 can generate, by using the difference in the wavelength sensitivity characteristics of the respective sensors, near-infrared light image data corresponding to image data acquired by irradiating only the near-infrared light and visible light image data corresponding to image data acquired by irradiating only the visible light, with respect to color image data acquired in a state where a plurality of wavelengths of light (near-infrared light and visible light) are simultaneously irradiated from the light source. In this case, the light amount of the near-infrared light is adjusted so that the brightness (for example, average brightness value or the like) of the finger region of the near-infrared light image data is included in an appropriate range, and the light amount of the visible light is adjusted so that the brightness of the finger region of the visible light image data is included in an appropriate range. In addition, in the present embodiment, it is assumed that the light amounts of the near-infrared light and the visible light are adjusted in advance.

[0055] Further, the processor 311 drives the imaging section 102. The imaging section 102 performs photographing to generate image data, and stores the image data as finger image data in the data storage 106 (step S407). Thus, the photographing correspondence processing ends (step S408).

[0056] Figure 5 is a flowchart for explaining another example of photographing correspondence processing performed by the photographing device 108. Figure 5 is an example in which the processing of steps S409 to S414 is added to the photographing correspondence processing of Figure 4 is an example of processing in a case where an object other than the finger is detected in the binary image data due to the influence of noise such as ambient light in step S405 of Figure 4 The photographing correspondence processing of is an example in which the processing of steps S409 to S414 is added to the photographing correspondence processing of

[0057] In a case where a finger is not detected in step S405 (step S405: No), the processor 311 determines whether or not an object other than a finger is detected in the binary image data (step S409). Here, detection of an object means that there is a region included in the foreground region other than the finger region. The processor 311 determines, for example, whether or not the proportion of the foreground region in the image data with respect to the entire region exceeds a predetermined value, and determines that an object is detected in a case where the proportion of the foreground region exceeds the predetermined value. Note that it is assumed that, in step S405, it is determined whether or not a finger is detected based on whether or not the contour line of the finger region shows the shape of a finger.

[0058] In a case where an object is not detected (step S409: No), the processor 311 returns to the process of step S402. On the other hand, in a case where an object is detected (step S409: Yes), the processor 311 controls the light source control section 300 to irradiate light from the light source 101 in a third irradiation mode (step S410).

[0059] The third irradiation mode is a mode for detecting a finger in a case where an object is detected, and is a mode in which both near-infrared light and visible light are irradiated from the light source 101. In the third irradiation mode, the light amount of the visible light is larger than the light amount of the visible light in a case where the visible light is irradiated in the first irradiation mode. The light amounts of the near-infrared light and the visible light may, for example, be values set in advance, or may be calculated by the processor 311 based on the light amount of the near-infrared light irradiated from the light source 101 in step S402 and the brightness of the finger image data acquired in step S403.

[0060] The processor 311 drives the imaging section 102. The imaging section 102 performs imaging to generate image data, and stores the image data as finger image data in the data storage 106 (step S411). Next, the processor 311 performs background removal processing of removing the background from the finger image data stored in the data storage 106 (step S412). Here, the image data is image data based on a plurality of wavelengths of light (near-infrared light and visible light), and in this case, the accuracy of the background removal processing can be improved compared to image data based on a single wavelength of light, and an object can be removed as the background with high accuracy.

[0061] Further, the processor 311 analyzes the image data from which the background has been removed by the background removal processing, and executes a finger detection process for detecting a finger region in which the fingers 111 to 113 are photographed in the image data (step S413). The processor 311 determines whether or not a finger is detected on the basis of binary image data that is a result of the finger detection process (step S414). Here, it is assumed that it is determined whether or not a finger is detected in accordance with whether or not the finger region shows the shape of a finger. Further, the processor 311 returns to the process of step S402 in a case where a finger is not detected (step S414: No), and shifts to the process of step S406 in a case where a finger is detected (step S414: Yes).

[0062] Further, in a case where an object other than a finger is detected, a finger can also be detected using another mechanism such as a range-finding sensor, which is not illustrated.

[0063] Figure 6 is a flowchart for explaining an example of the registration process that is a process performed after the photographing correspondence process by the photographing device 108.

[0064] In the registration process, after the photographing correspondence process ends (step S408), the processor 311 reads out the finger image data stored in the data storage 106 (step S601). The processor 311 detects a finger region from the read-out finger image data by image processing (step S602), and performs a normalization process for normalizing the finger image data on the basis of the finger region (step S603). The normalization process is a process for correcting the magnification and distortion of the finger region due to the position and posture of the finger.

[0065] The processor 311 extracts feature data representing a feature of the finger from the normalized finger image data (step S604), and saves the feature data as registration feature data to the data storage 106 or the storage device 312 (step S605), and ends the process. As for the feature data, in the present embodiment, a feature of a blood vessel of the finger (blood vessel pattern and the like) and a feature of the surface of the finger (fingerprint and the like), the processor 311, for example, separates the finger image data into finger blood vessel image data that is near-infrared light image data and finger surface image data that is visible light image data, and extracts the feature data from the finger blood vessel image data and the finger surface image data, respectively. Further, the feature data is extracted for each of the fingers 111 to 113.

[0066] Further, the processor 311 can also store the user ID and password, which are the authentication information on the authenticated person, in correspondence with the registered feature data. At this time, the processor 311 can receive the user ID and password from the authenticated person via the input device 313, or can acquire the same from an IC chip or a communication terminal held by the authenticated person via the communication IF 315. Further, the processor 311 can also not perform the extraction of the feature data in step S604, and store the finger image data in the data storage 106 or the storage device 312.

[0067] Figure 7 is a flowchart for explaining an example of the authentication processing as processing performed after the photographing corresponding processing by the imaging device 108. The authentication processing and Figure 6 The registration processing of

[0068] In the authentication processing, the above-described processing of steps S601 to S604 is first performed. Then, the processor 311 performs a collation processing of collating the feature data extracted in step S604 with the registered feature data registered in the data storage 106 or the storage device 312 in the registration processing (step S705).

[0069] The collation processing can be a 1-to-1 authentication processing of collating the registered feature data collated with the feature data with the registered feature data corresponding to the same authenticated person information as the authenticated person information acquired via the input device 313 or the communication IF 315, or can be a 1-to-N authentication processing of collating the feature data with each of the registered feature data registered in the data storage 106 or the storage device 312. Further, in the present embodiment, the feature data of each of the index finger 111, the middle finger 112, and the ring finger 113 is collated respectively.

[0070] The processor 311 determines whether or not the authentication of the authenticated person is successful based on the processing result of the collation processing (step S706). Here, the processor 311 determines the identity of the feature data and the registered feature data, and calculates the collation score based on the determination result thereof. The identity is a numerical value indicating the difference between the feature (the pattern of the blood vessels of each finger and the fingerprint, etc.) exhibited by the feature data and the feature exhibited by the registered feature data, and is contained in a prescribed allowable range. The processor 311 determines the identity for each feature, and the more features that satisfy the identity, the higher the collation score is made. Further, the processor 311 determines whether or not the collation score is greater than the threshold value TH, and determines whether or not the authentication of the authenticated person is successful.

[0071] In the case where the collation score is equal to or less than the threshold value TH (step S706: No), the processor 311 determines that the biometric authentication of the authenticated person has failed, and determines to reject the authentication of the authenticated person from Figure 4The step S401 starts with whether or not the timeout time has elapsed (step S707). The processor 311, in the case where the timeout time has not elapsed (step S707: No), returns to the step S401. Figure 4 or Figure 5 The processing of the step S406 ends the authentication processing in the case where the timeout time has elapsed (step S707: Yes).

[0072] On the other hand, in the case where the score ratio is larger than the threshold TH (step S706: Yes), the processor 311 judges that the biological authentication of the person to be authenticated is successful, executes a prescribed post-authentication processing (step S708), and ends the authentication processing.

[0073] As explained above, according to the present embodiment, the light source 101 is capable of irradiating the visible light and the non-visible light as the irradiation light. The imaging section 102 captures the irradiation region irradiated with the irradiation light, and acquires the image data. The processor 311 causes the imaging section 102 to acquire the detection image data in the first irradiation mode in which the non-visible light is irradiated from the light source 101, and judges whether or not the biological body is presented into the irradiation region on the basis of the detection image data. In the case where the biological body is presented, the processor 311 causes the imaging section 102 to acquire the biological body image data in which the biological body is captured as the image data in the second irradiation mode in which the visible light and the non-visible light are irradiated from the light source 101. Therefore, the visible light irradiation for acquiring the biological body image data can not be performed until the biological body is presented, so that the situation in which the light irradiated from the light source before the biological body is presented in front of the light source 101 enters into the eyes of the person to be authenticated and the surrounding people and causes the people to feel dazzled can be alleviated. Thus, the discomfort caused by the visible light can be alleviated.

[0074] Further, in the present embodiment, since the visible light is also irradiated from the light source in the first mode at a light amount smaller than that of the non-visible light, the person to be authenticated can be notified that the authentication device 108 is in the authentication state in which the authentication is performed while the discomfort caused by the visible light is alleviated.

[0075] [Embodiment 2]

[0076] Embodiment 2 is a modification of Embodiment 1, and is an example in which the authentication accuracy is improved by detecting a shadow region included in the image data. Hereinafter, the structure and operation different from Embodiment 1 will be mainly explained.

[0077] Figure 8 is a diagram showing a structure example of the main body 100 relating to the present embodiment. Figure 8 (a) is a side sectional view of the main body 100, Figure 8 (b) is a plan view of the main body 100.

[0078] In Figure 8In this example, there are four light sources 101, referred to as light sources 101-1 to 101-4 when differentiation is necessary. Light sources 101-1 and 101-3 correspond to the index finger 111 and are arranged in the X direction. For example, light source 101-1 is positioned corresponding to the fingertip of the index finger 111, and light source 101-3 is positioned corresponding to the base of the index finger 111. Light sources 101-2 and 101-4 correspond to the ring finger 113 and are arranged in the X direction. For example, light source 101-2 is positioned corresponding to the fingertip of the ring finger 113, and light source 101-4 is positioned corresponding to the base of the ring finger 113. Furthermore, the groups of light sources 101-1 and 101-2 and light sources 101-3 and 101-4 are arranged in the Y direction. The camera unit 102 is positioned in the XY plane surrounded by light sources 101-1 to 101-4. Each light source 101 can also be composed of multiple light sources that respectively irradiate near-infrared light and visible light.

[0079] Furthermore, a fingertip display plate 130 is provided at a position in the +Z direction from the second optical filter 104 corresponding to the light sources 101-1 and 101-3, for guiding the fingertips of the user's presented hand 110 to an appropriate position. The fingertip display plate 130 is formed of a transparent plate-like component such as acrylic or glass. Figure 8 In the example, the finger is supported by the housing 100A in a state parallel to the XY plane. Thus, the entire finger can be captured by the camera unit 102 when the person being certified places their finger on the fingertip display plate 130 or without touching the ground cover.

[0080] However, in Figure 8 In the example, the fingertip display panel 130 is a protruding structure that projects shadows onto the fingers 111-113 in the illumination area presented to the light source 101. This may result in shadow regions in the finger image data caused by the fingertip display panel 130. In this case, it is difficult to accurately detect fingers, potentially leading to a decrease in authentication accuracy. Furthermore, even if a finger is detected, the shadow region is included as noise information in the feature data, which could also cause a decrease in authentication accuracy.

[0081] Figure 9 This is an example diagram used to illustrate the shadow region. For example... Figure 9 As shown, most of the illumination light from the light sources 101-1 and 101-2 on the fingertip side is transmitted through the fingertip display plate 130. However, in the region of the edge 130a on the root side of the finger of the fingertip display plate 130, due to the increased refractive index of the illumination light, very little of the illumination light travels in a straight line through the fingertip display plate 130. As a result, in the finger image data 1500, the edge of the fingertip display plate 130 is projected onto the finger region as a shadow region 1600.

[0082] Thus, in a case where the shadow region is included in the finger image data, the processor 311 is able to suppress a decrease in authentication accuracy and the like by performing shadow corresponding processing corresponding to the shadow region.

[0083] <Example of removing a shadow region from a living body region>

[0084] The processor 311 detects the shadow region 1600 by utilizing a difference in luminance of the finger image data (finger blood vessel image data and finger surface image data) corresponding to the plurality of wavelength lights, based on a difference in light absorption characteristics of a living body with respect to the plurality of wavelength lights. Specifically, near-infrared light is easily scattered and reflected in an inside of a living body that is shallow from a surface of the living body, because the near-infrared light has a characteristic of being more easily transmitted through the living body than visible light. Thus, the near-infrared light easily propagates to the shadow region 1600. On the other hand, the visible light is difficult to propagate to the shadow region 1600 because the visible light is reflected on the surface of the living body. Thus, the shadow region 1600 of the finger image data 1500 taken by the near-infrared light is easily in a brighter state than the shadow region 1600 of the finger image data 1500 taken by the visible light. Therefore, the processor 311 detects the shadow region 1600 by utilizing a difference in luminance of the near-infrared light image data and the visible light image data, and excludes the shadow region 1600 from the extraction target region from which the feature data is extracted. Thus, it is possible to maintain a high authentication accuracy.

[0085] As a specific method of detecting the shadow region 1600, for example, a method in which the processor 311 detects, as the shadow region 1600, a region in the finger region corresponding to the vicinity of the edge 130a of the fingertip presentation board 130, which is smaller in luminance than the surrounding region, and which is smaller in luminance of the visible light image data than in luminance of the near-infrared light image data, can be considered.

[0086] Further, in the detection of the shadow region 1600, not only a simple difference in luminance but also a difference in luminance variation within an image can be utilized. The near-infrared light easily propagates to the shadow region 1600 as described above, so the luminance variation of the boundary of the shadow region 1600 of the near-infrared light image data is gentle, and the boundary line becomes blurred. On the other hand, the visible light is difficult to propagate to the shadow region 1600, so the boundary of the shadow region 1600 of the visible light image data sharply changes in luminance compared to the near-infrared light image data. Thus, the processor 311 can also detect, as the shadow region 1600, a region which is smaller in luminance than the surrounding region, and which is sharper in luminance variation of the visible light image data than in luminance variation of the near-infrared light image data. In addition, the processor 311 can also detect the shadow region 1600 by combining the difference in luminance and the difference in luminance variation.

[0087] Furthermore, near-infrared light image data and visible light image data can be acquired separately at different times, or they can be separated from finger image data captured by simultaneously irradiating near-infrared light and visible light. Moreover, the method for separating the finger image data into image data of different wavelengths is not particularly limited. For example, if the camera unit 102 includes multiple sensors with different wavelength sensitivity characteristics, the camera unit 102 acquires finger image data by simultaneously irradiating multiple different wavelengths of light (near-infrared light and visible light) from the light source 101 and capturing images of fingers 111-113 using reflected light from fingers 111-113. The processor 311 can perform image processing on the finger image data, utilizing the differences in wavelength sensitivity characteristics of each sensor, to separate the finger image data.

[0088] <An example of finger pose detection based on shadow regions>

[0089] The processor 311 can also detect at least one of the finger position and posture based on the detected shadow region 1600. The position and brightness of the shadow region 1600 change according to the positional relationship between the occluder that generates the shadow region 1600, the light source 101, and the organism (fingers 111-113). For example, in... Figure 9 In the example, if the hand moves in the Z direction, the position of the shadow region 1600 within the finger image data moves in both the X and Y axes. Therefore, if the position of the shadow region 1600 in the finger image data deviates from the reference position by a predetermined distance (pixels), the processor 311 can determine that the fingers 111-113 have moved out of their proper positions and notify the authenticator of this situation via an output device 314 or the like. The reference position is the position of the shadow region 1600 that occurs when the finger is presented in the proper position, and is, for example, pre-registered in a storage device 312 or the like.

[0090] Furthermore, the posture of fingers 111-113 is not as described. Figure 9 In cases where the shadow region 1600 is in a horizontal posture, or a posture with the fingertips lowered or the fingers bent, the shadow region 1600 deforms relative to the posture of the fingers 111-113 when the posture is horizontal. Therefore, the processor 311 can also determine whether the fingers 111-113 have deviated from the appropriate posture by judging whether the deformation of the shadow region 1600 has deviated from the appropriate range.

[0091] Figure 10 These are diagrams used to illustrate other examples of shadow regions. In Figure 10 In the example, the camera device 108, besides... Figure 8The structure represented by the arrow A indicates that the finger 111 is in a proper position and posture. The structure represented by the arrow B indicates that the finger 111 is in a proper position but not in a proper posture. The structure represented by the arrow C indicates that the finger 111 is not in a proper position but in a proper posture. The structure represented by the arrow D indicates that the finger 111 is not in a proper position and not in a proper posture. The structure represented by the arrow E indicates that the finger 111 is in a proper position and in a proper posture. The structure represented by the arrow F indicates that the finger 111 is not in a proper position and not in a proper posture. The structure represented by the arrow G indicates that the finger 111 is in a proper position but not in a proper posture. The structure represented by the arrow H indicates that the finger 111 is not in a proper position but in a proper posture. Figure 10 In the example of FIG. 17, the protrusion structure 800 is provided at the root side of the finger.

[0092] In the example of FIG. 17, the protrusion structure 800 is provided at the root side of the finger. Figure 10 In the example of FIG. 17, the processor 311 can detect at least one of the position and the posture of the finger based on the shadow region 1601 caused by the protrusion structure 800. For example, the processor 311 can detect whether the fingers 111 to 113 are out of a proper position by judging whether the position of the shadow region 1601 in the finger image data deviates from a reference position by a prescribed distance or more. In addition, the closer the fingers 111 to 113 are to the protrusion structure 800, the closer the position of the shadow region 1601 in the finger image data 1500 is to the position of the protrusion structure 800, and the more definite the boundary line of the shadow region is. Thus, the processor 311 can also detect whether the fingers are out of a proper position based on the distance of the shadow region 1601 from the protrusion structure 800 in the finger image data 1500 and the definiteness of the boundary line of the shadow region. In addition, the processor 311 can also judge whether the fingers 111 to 113 are out of a proper posture by judging whether the deformation of the shadow region 1601 is out of a proper range.

[0093] The specific method of detecting at least one of the position and the posture of the finger based on the shadow region 1601 caused by the protrusion structure 800 is the same as the method of detecting at least one of the position and the posture of the finger based on the shadow region 1600 caused by the fingertip presentation plate 130.

[0094] <Example of detecting a finger region considering a shadow region>

[0095] Figure 11 is a diagram for explaining an example of detecting a finger region considering a shadow region. As Figure 11As shown, in a state where the plurality of fingers 111 to 113 approach and the finger 112 is positioned further in the +Z direction than the fingers 111 and 113 adjacent to the finger 112, the irradiation light to the finger 112 is blocked by the fingers 111 and 113, so a shadow region 1602 occurs in the finger image data 1500. In this case, determination of the outline of the finger becomes difficult, and the detection accuracy of the finger can possibly decrease. In this case, the processor 311 also detects a region where the luminance is smaller than the surrounding region and the luminance of the visible light image data is smaller than the luminance of the near-infrared light image data as the shadow region 1601, or a region where the luminance is smaller than the surrounding region and the luminance variation of the visible light image data is sharper than the luminance variation of the near-infrared light image data as the shadow region 1602, and can perform more correct finger detection.

[0096] In addition, the present embodiment can be implemented independently of Embodiment 1.

[0097] As explained above, according to the present embodiment, the processor 311 detects a shadow region representing a shadow projected to a living body from the living body image data, and performs shadow corresponding processing corresponding to the shadow region. Therefore, in the case where the shadow region exists, it is also possible to suppress a decrease in the authentication accuracy.

[0098] Further, in the present embodiment, the shadow corresponding processing is processing of removing the shadow region from a living body region in which the living body is photographed, included in the living body image data. In this case, it is also possible to suppress a decrease in the authentication accuracy in the case where the shadow region occurs.

[0099] Further, in the present embodiment, the shadow corresponding processing is processing of detecting at least one of the position and the posture of the living body based on the shadow region. In this case, it is possible to notify the person to be authenticated of the message in the case where at least one of the position and the posture of the living body is inappropriate, so it is possible to perform the living body authentication with an appropriate position and posture, and it is possible to suppress a decrease in the authentication accuracy.

[0100] Further, in the present embodiment, since the protrusion structure 800 that projects the shadow to the living body is provided, it is possible to appropriately perform the detection of at least one of the position and the posture of the living body based on the shadow region.

[0101] Further, in the present embodiment, since the shadow region is detected based on the non-visible light image data and the visible light image data separated from the living body image data, it is possible to correctly detect the shadow region.

[0102] [Embodiment 3]

[0103] Embodiment 3 is a modification of Embodiment 1, and is an example of suppressing occurrence of a brightness saturation region in the finger image data in Embodiment 1. Hereinafter, mainly the structure and operation different from Embodiment 1 will be described.

[0104] Figure 12 is a diagram for explaining a brightness saturation region. As shown in Figure 12 , the light amount of the irradiation light of the light source 101 is the largest on the optical axis 1700. Therefore, the pixels on the finger image data corresponding to the biological part irradiated with the irradiation light on the optical axis 1700 are likely to cause the brightness value to reach the upper limit, resulting in a brightness saturation. The brightness saturation region, which is a region of pixels in the finger image data where the brightness saturation has occurred, is likely to cause a decrease in the authentication accuracy due to the lack of information of the feature data. Thus, it is preferable that the brightness saturation region does not occur in the finger image data.

[0105] Figure 13 is a flowchart for explaining an example of a light source control process for suppressing occurrence of a brightness saturation region. The light source control process is performed, for example, between steps S405 and S406 of Figure 4 .

[0106] First, if it becomes the start timing of the light source control process, the processor 311 controls the light source control section 300 to irradiate light from the light source 101 in the 2nd irradiation mode (step S1300). The processor 311 drives the imaging section 102. The imaging section 102 performs imaging to generate image data, and stores the image data as finger image data in the data storage 106 (step S1301).

[0107] The processor 311 analyzes the image data stored in the data storage 106, and executes a finger detection process for detecting a finger region in which the fingers 111 to 113 are imaged in the image data (step S1302). Also, the processor 311 calculates the brightness of the finger region (step S1303). The brightness of the finger region is, for example, an average value of the brightness values of the pixels included in the finger region, that is, an average brightness value.

[0108] The processor 311 determines whether the brightness of the finger region is included in a prescribed appropriate range (step S1304).

[0109] In a case where the brightness of the finger region is included in the appropriate range (step S1304: YES), the processor 311 performs a brightness saturation detection process for detecting a brightness saturation region, on the basis of the brightness information of the finger region (step S1305). Further, the processor 311 determines whether or not the brightness saturation region is detected on the basis of the processing result of the region detection process (step S1306). The brightness saturation detection process is, for example, a process of counting the number of pixels having the upper limit value of the brightness value. The processor 311 determines that the brightness saturation region is detected, for example, in a case where the number of pixels having the upper limit value of the brightness value is equal to or greater than a prescribed value.

[0110] In a case where the brightness of the finger region is not included in the appropriate range (step S1304: NO), and in a case where the brightness saturation region is not detected (step S1306: NO), the processor 311 calculates, as the irradiation light amount in the second irradiation mode, an appropriate light amount of the irradiation light of the light source 101 that makes the brightness of the finger region appropriate, on the basis of the brightness of the finger region (step S1307). For example, an appropriate value of the brightness of the finger region is registered in advance in the data storage 106 or the storage device 312, and the processor 311 calculates the appropriate light amount on the basis of the difference between the brightness of the finger region and the appropriate value, and the light amount of the irradiation light irradiated in step S1300. In this case, even in a case where the presentation position of the fingers 111 to 113 in the Z direction (the height of the fingers 111 to 113) varies, it is possible to irradiate the fingers 111 to 113 with light of a uniform intensity.

[0111] In a case where the brightness saturation region is detected (step S1306: YES), the processor 311 calculates the appropriate light amount on the basis of the brightness of the finger region, and further calculates, as the irradiation light amount, a light amount obtained by subtracting a prescribed light amount from the appropriate light amount, to suppress the brightness saturation region (step S1307).

[0112] In the present embodiment, the prescribed light amount is subtracted from the appropriate light amount in a case where the brightness of the finger region is included in the appropriate range, to suppress the brightness saturation region. That is, since the brightness of the entire finger region becomes an appropriate brightness, the prescribed light amount is preferably set to a small value. The prescribed light amount can be set in advance, or can be determined based on the size of the brightness saturation region or the proportion of the brightness saturation region in the finger region, or the like. Furthermore, the same prescribed light amount can be used for the plurality of light sources 101, or the prescribed light amount can be subtracted from the appropriate light amount only for the light source 101 disposed at the position closest to the finger or the portion where the brightness saturation region has occurred. Furthermore, as described above, the near-infrared light is internally scattered and diffusely reflected toward the outside of the living body in a shallow portion inside from the surface of the living body, and the visible light is easily reflected on the surface of the living body. Therefore, the visible light is more likely to cause brightness saturation than the near-infrared light. Thus, the prescribed light amount can be subtracted from the appropriate light amount only for the light source 101 that irradiates the visible light.

[0113] Further, the processor 311 lights up the light source 101 at the irradiation light amount decided in step S1307 or S1308 (step S1309), and ends the light source control processing (step S1310).

[0114] In addition, the same processing as that of step S1306 can be performed after the processing of step S1307. In this processing, in a case where the brightness saturation region is detected, the processing of step S1308 is performed, and in a case where the brightness saturation region is not detected, the processing of step S1309 is performed.

[0115] As described above, according to the present embodiment, the processor 311 reduces the light amount of the irradiation light in the second irradiation mode in a case where the brightness saturation region is present in the living body image data. Thus, it is possible to suppress the brightness saturation region, and it is possible to suppress the decrease in the authentication accuracy.

[0116] [Embodiment 4]

[0117] Embodiment 4 is a modification of Embodiment 1, and is an example in which the finger detection accuracy is improved by utilizing the difference between the light amount of the light irradiated by the light source 101 and the light amount of the ambient light in the finger detection processing (step S404). Hereinafter, mainly the structure and operation different from Embodiment 1 will be described.

[0118] In Embodiment 1, a finger is detected using near-infrared light image data. In this case, there is no particular problem in a case where the light amount of near-infrared light included in the ambient light assumed in Embodiment 1 is sufficiently smaller than the light amount of near-infrared light included in the irradiation light of the light source 101. However, in a case where the light amount of near-infrared light included in the ambient light is large, since the near-infrared light becomes strong in both the finger region and the background region, it is difficult to distinguish the finger region and the background region, and it can not be possible to appropriately determine the finger region.

[0119] In the present embodiment, the processor 311, in the first irradiation mode, irradiates visible light with a light amount smaller than that of the near-infrared light while irradiating the near-infrared light from the light source 101. The processor 311 separates the image data acquired in the first irradiation mode into visible light image data and near-infrared light image data, and determines whether a living body is presented based on the visible light image data and the near-infrared light image data.

[0120] For example, the processor 311 separates the image data stored in the data storage 106 into near-infrared light image data and visible light image data. In the visible light image data, in a case where the light amount of visible light included in the ambient light is larger than the light amount of visible light irradiated by the light source 101, the vicinity of the boundary line between the finger region and the background region is brighter (the luminance becomes larger) than the inside of the finger region, and in a case where the light amount of visible light included in the ambient light is smaller than the light amount of visible light irradiated by the light source 101, the entire finger region becomes relatively brighter (the luminance becomes larger) than the background region.

[0121] In this case, the processor 311 determines, in the visible light image data, a region in which the luminance is larger in the vicinity of the boundary line between the foreground region and the background region or a region in which the luminance is larger in the foreground region as a finger candidate region. Also, the processor 311 determines, for example, a region in which the finger candidate region in the visible light image data overlaps the foreground region in the near-infrared light region as a finger region.

[0122] As described above, in the present embodiment, the processor 311 separates the image data into visible light image data and near-infrared light image data, and determines whether a living body is presented based on the visible light image data and the near-infrared light image data. Therefore, it is possible to more appropriately determine whether a living body is presented.

[0123] The above-described embodiments of the present application are examples for describing the present application, and are not intended to limit the scope of the present application to only these embodiments. Those skilled in the art can implement the present application in other various modes without departing from the scope of the present application.

Claims

1. A photographic device, wherein, have: The irradiation unit is capable of using both visible and invisible light as irradiation light. The camera unit captures images of the illuminated area by the aforementioned illumination light; and The control unit, at the start timing of the start of shooting, illuminates the irradiation unit with a first mode of light, which is a combination of invisible light and visible light with a lower intensity than the invisible light. In the first mode, the camera unit acquires a detection image as the image. Based on this detection image, it determines whether a living organism is present in the irradiated area. If a living organism is present, the control unit then illuminates the irradiation unit with a second mode of light, which is a combination of invisible light and visible light with a higher intensity than the visible light illuminated in the first mode, and the camera unit acquires an image of the organism as the image. The control unit separates the detection image into a visible light image based on visible light and a non-visible light image based on non-visible light. It determines a candidate area for a living organism in the visible light image and defines the area where the candidate area for a living organism overlaps with the foreground area in the non-visible light image as the living organism area. Based on the living organism area, it determines whether a living organism is present in the irradiated area.

2. The photographic apparatus as claimed in claim 1, wherein, The control unit detects the shadow region in the image of the organism that represents the shadow projected onto the organism, and performs shadow correspondence processing corresponding to the shadow region.

3. The photographic apparatus as claimed in claim 2, wherein, The aforementioned control unit performs the aforementioned shadow region removal process from the biological region containing the biological entity in the aforementioned biological entity image as part of the aforementioned shadow correspondence processing.

4. The photographic apparatus as claimed in claim 2, wherein, The aforementioned control unit performs processing based on the shadow region to detect at least one of the position and posture of the organism as part of the shadow correspondence processing.

5. The photographic apparatus as claimed in claim 4, wherein, It also has a protruding structure that projects the shadow onto the organism being illuminated in the aforementioned irradiation area.

6. The photographic apparatus as claimed in claim 2, wherein, The control unit separates the biological image into a visible light image based on visible light and a non-visible light image based on non-visible light, and detects the shadow region based on the visible light image and the non-visible light image.

7. The photographic apparatus as claimed in claim 1, wherein, The control unit determines whether there is a brightness saturation region in the biological image. If the brightness saturation region exists, the amount of light irradiated in the second mode is reduced.

8. An authentication device, wherein, have: The photographic apparatus of claim 1; and The authentication department performs biometric authentication based on the aforementioned biometric images.

9. A method for photographing organisms, comprising a photographic apparatus having an irradiation unit and an imaging unit, wherein the irradiation unit is capable of irradiating the organism with both visible and invisible light, and the imaging unit captures an image of the irradiated area. In the above-mentioned methods of photographing organisms, At the start time of the start of shooting, a first mode of illumination light is used to illuminate the above-mentioned illumination unit with non-visible light and visible light with a light intensity less than that of the non-visible light. In the above-mentioned first mode, the above-mentioned imaging unit acquires a detection image as the above-mentioned image. Based on the above-mentioned detection images, it is determined whether a living organism is present in the above-mentioned irradiated area; When the aforementioned organism is presented, the imaging unit acquires an image of the organism by irradiating the aforementioned irradiation unit with a second mode in which non-visible light and visible light with a light intensity greater than that of the visible light irradiated in the aforementioned first mode. In the above determination, the detection image is separated into a visible light image based on visible light and a non-visible light image based on non-visible light. A candidate area for a living organism is determined in the visible light image, and the area where the candidate area for a living organism overlaps with the foreground area in the non-visible light image is determined as the living organism area. Based on the living organism area, it is determined whether a living organism is present in the irradiated area.

Images