JP2007041831A - Biological discrimination device, authentication device, and biometric identification method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a biological discrimination device and an authentication device capable of effectively performing biological discrimination even for a spherical forgery such as a false eye similar to a living eye. <P>SOLUTION: The biological discrimination device includes an imaging part 2 for imaging a subject eye 31 from a direction oblique to its visual line; an iris detecting part 11 for detecting an elliptic iris image from the image taken by the imaging part 2; and a biological discrimination part 13 for discriminating whether or not the subject is a living eye 31 depending on whether or not an iris image has been detected by the iris detecting part 11. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a living body determination device that determines whether or not a subject is a living body, an authentication device that performs personal authentication of a subject, and a living body determination method that determines whether or not a subject is a living body.

  In recent years, as a method of personal authentication at the time of access in devices requiring high security such as entry / exit management devices and information devices storing important information such as personal information, human fingerprints, irises, fundus blood vessels, facial Various authentication methods using information unique to the person to be authenticated, such as features, blood vessel patterns of hands and arms, so-called biometric information, have been put into practical use.

  Among them, an authentication method that uses the difference in the eyelid pattern of the iris part of the eye (hereinafter referred to as “Iris Authentication”) due to its high reliability such as the high identity authentication rate and low acceptance rate of others. (Referred to as Patent Document 1, for example).

  In such an iris authentication method, an iris part is selectively encoded from an image of an eye part of the person to be authenticated (hereinafter, this image is referred to as an eye image), and the obtained information is registered in advance as authentication information. This is a method of comparing and collating with the information (hereinafter referred to as registration authentication information), and authenticating that the person to be authenticated is a person registered in advance if it is determined that they match each other.

  The iris authentication method has a problem of so-called “spoofing” in which an unauthorized person can be authenticated as being a pre-registered person by using a printed matter or a photograph on which an iris pattern is printed. It has been pointed out that solving such problems has become an issue.

In order to prevent such “spoofing”, for example, utilizing the fact that the eye of a living body is a substantially spherical body, the LED is placed at a position where the image is reflected in the pupil, and the LED is placed in the pupil. When an image is reflected, it is determined that the subject is an eye of a living body, and when an LED image does not appear in the pupil, a technique for determining that the subject is a counterfeit such as a photograph has been proposed. (For example, refer to Patent Document 2).
Japanese Patent No. 3307936 JP 2000-298727 A

  However, in the technology as described above, although it is possible to perform biometric determination on a planar forgery such as a photograph or a printed matter, a spherical counterfeit such as a fake eye, as in the case of a living eye. However, there is a problem that it is difficult to perform biometric discrimination.

  The present invention has been made in view of such a problem, and a living body discrimination device capable of effectively performing a living body discrimination on a spherical forgery similar to a living eye such as a false eye and the like, and An object is to provide an authentication device and a biometric discrimination method.

  The living body discrimination device of the present invention determines whether or not a subject is a living body based on an imaging unit that captures the subject's eyes from an oblique direction with respect to the line-of-sight direction and an image of the subject's eyes captured by the imaging unit. It is characterized by comprising a biometric discrimination unit for discrimination.

  With such a configuration, the subject's eye is photographed from an oblique direction, and the living body is discriminated based on the image. Therefore, the structure of the spherical forgery similar to that of a living eye such as a fake eye It is possible to provide a living body discriminating apparatus that can effectively perform living body discrimination based on the difference.

  In addition, an iris detection unit that detects an iris image from an image of the subject's eye photographed by the photographing unit, and the biometric determination unit determines whether the iris image detected by the iris detection unit is elliptical or not, It may be configured to determine whether or not the subject is a living body.

  According to such a configuration, it is possible to effectively perform biometric discrimination on a counterfeit object in which an iris pattern is pasted on the surface of a spherical object.

  Further, the living body determination unit may be configured to determine that the subject is a living body when the iris image detected by the iris detection unit has an elliptical shape.

  According to such a configuration, for an imitation such as an iris pattern pasted on the surface of a spherical object, an effective biometric discrimination is made by taking advantage of the fact that the iris image does not become an ellipse when taken from an oblique direction. It can be performed.

  Also, a gaze guidance unit that guides the subject to move the gaze, an iris detection unit that detects an iris image from the eye image of the subject photographed by the photographing unit, and a subject photographed by the photographing unit A pupil detection unit that detects a pupil image from the image of the eye of the subject, the imaging unit captures the eye in a state in which the line of sight of the subject is guided, and the living body determination unit includes the iris detected by the iris detection unit It may be configured to determine whether or not the subject is a living body based on the positional relationship between the image and the pupil image detected by the pupil detection unit.

  According to such a configuration, it is possible to effectively perform biometric discrimination even for a counterfeit in which an iris is formed inside.

  Further, the living body determination unit is configured to determine that the subject is not a living body when the center position of the iris image detected by the iris detection unit matches the center position of the pupil image detected by the pupil detection unit. There may be.

  According to such a configuration, further, when the line of sight is moved, when the image is taken from an oblique direction with respect to the line of sight, the living body discrimination using a phenomenon peculiar to the living body that the center of the pupil does not coincide with the center of the iris. It can be performed.

  Moreover, the structure provided with the light source part which irradiates the area | region including at least eyes of a to-be-photographed object may be sufficient.

  According to such a configuration, an eye image having an iris pattern with good contrast can be taken.

  Moreover, the structure provided with the image quality determination part which determines the image quality of the image image | photographed with the imaging | photography part may be sufficient.

  According to such a configuration, since it is possible to perform biometric discrimination for an image determined to have good image quality, it is possible to perform more reliable biometric discrimination.

  Moreover, the structure provided with the eye detection part which detects eyes from the image image | photographed with the imaging | photography part may be sufficient.

  According to such a configuration, since it is possible to perform biometric discrimination on an image in which an eye is detected, it is possible to perform more reliable biometric discrimination.

  Next, the authentication device of the present invention includes a living body discrimination device, a circular correction unit that corrects an elliptical iris image detected by the iris detection unit into a circular shape, and an iris image that has been corrected to a circular shape by the circular correction unit. And an authentication processing unit for performing subject authentication processing.

  According to such a configuration, since the eye of the subject is photographed from an oblique direction and the living body discriminating device that performs the living body discrimination based on the image is provided, the spherical shape similar to that of the living eye such as a false eye is provided. It is possible to provide an authentication apparatus that can effectively perform biometric discrimination against a counterfeit based on the difference in structure.

  Next, the authentication device of the present invention includes the biometric device of the present invention and an authentication processing unit that performs subject authentication processing using an elliptical iris image detected by the iris detection unit. To do.

  Even with such a configuration, since the subject eye is photographed from an oblique direction and a living body discriminating apparatus that performs living body discrimination based on the image is provided, a spherical forgery similar to that of a living eye such as a fake eye is provided. It is also possible to provide an authentication device that can effectively perform biometric discrimination on an object based on the difference in structure.

  Next, the living body discrimination method of the present invention is based on a first step in which the subject's eyes are photographed from an oblique direction with respect to the line-of-sight direction, and the subject's eyes are imaged based on the subject's eye images photographed in the first step. And a second step of determining whether or not the subject is a living body.

  According to such a configuration, since the subject's eye is photographed from an oblique direction and the living body is determined based on the image, even for a spherical forgery similar to a living eye such as a fake eye, It is possible to provide a living body discrimination method capable of effectively performing living body discrimination based on the difference in structure.

  Next, the biometric discrimination program of the present invention includes a first step in which an image obtained by photographing the subject's eye from an oblique direction with respect to the line-of-sight direction is input to the computer, and the subject's eye input in the first step. And a second step of determining whether or not the subject is a living body based on the image.

  According to such a program, the subject's eye is photographed from an oblique direction, and the living body is discriminated based on the image. Therefore, even for a spherical forgery similar to a living eye such as a fake eye, It is possible to provide a biometric discrimination program capable of effectively performing biometric discrimination based on the difference in structure.

  As described above, according to the present invention, a living body discrimination device, an authentication device, and a living body that can effectively perform living body discrimination on a spherical counterfeit similar to a living eye such as a false eye. A determination method can be provided.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

(First embodiment)
First, the authentication device 1 according to the first embodiment of the present invention will be described. The function of the authentication device 1 according to the first embodiment of the present invention will be described with reference to FIGS. 1 and 2. FIG. 1 is a diagram illustrating a usage pattern of the authentication device 1 according to the first embodiment of the present invention, and FIG. 2 is a functional block diagram illustrating a configuration of the authentication device 1 according to the first embodiment of the present invention. It is.

  As shown in FIG. 1, the authentication device 1 according to the first embodiment of the present invention is oblique to the person to be authenticated 30 (the direction of the line of sight when the person to be authenticated 30 in FIG. The eye 31 of the person 30 to be authenticated is photographed by the photographing unit 2 from the direction having an angle θ with respect to the Z-axis direction).

  As described above, the authentication device 1 according to the first embodiment of the present invention does not need to be placed in front of the person to be authenticated 30, so that the person to be authenticated 30 is not aware of the existence of the authentication device 1. It is possible to perform biometric discrimination processing and authentication processing described later.

  Here, each functional block of the authentication device 1 in the first exemplary embodiment of the present invention will be described in detail.

  As shown in FIG. 2, the authentication device 1 according to the first embodiment of the present invention includes a light source unit 7 that irradiates an eye 31 of a person 30 to be authenticated who is a subject, and a target that is irradiated by the light source unit 7. The imaging unit 2 that captures an eye image including at least the iris of the eye 31 of the authenticator 30, image quality determination of the eye image captured by the imaging unit 2, and the like are sent to the authentication processing unit 17. Capture processing unit 3 that performs processing (hereinafter referred to as capture processing), authentication processing unit 17 that performs iris authentication processing by a predetermined method described later using an image captured by the capture processing unit 3, and authentication processing Based on the output from the unit 17, a biometric determination unit 13 that determines whether or not the subject is a living body by a method that will be described later, an output unit that outputs the authentication result in the authentication processing unit 17 and the biometric determination result in the biometric determination unit 13 3, and includes a light source unit 7, imaging unit 2, the capture processing unit 3, the biometric determination unit 13 and the authentication processing unit 17 control unit 6 for controlling the respective operations.

  The light source unit 7 can irradiate the eye 31 with a light beam having a near-infrared wavelength (a wavelength of about 700 nm to about 1000 nm) in order to capture a clear iris image with good contrast of the eye 31. A light source can be used.

  Further, the present invention is not limited to the configuration of the photographing unit 2, but as an example, a monochrome camera using a CCD can be used. As a lens system attached to the photographing unit 2, it is desirable to mount a telephoto lens that can magnify the region of the eye 31 and photograph it.

  The capture processing unit 3 further captures the image quality determination unit 9 that determines the image quality of the image from the image output from the imaging unit 2, and the portion regarded as the eye in the image output from the imaging unit 2. An eye detecting unit 10 for determining whether or not

  The image quality determination in the image quality determination unit 9 is performed by, for example, analyzing the frequency of an image using a high-quality image with a high amount of information of a predetermined high-frequency component, and calculating the information amount of the predetermined high-frequency component. A method of determining that the image quality is better as the integrated value increases can be used. In addition, as an image quality determination method in the image quality determination unit 9, a method of evaluating using variations in luminance values of the entire image can be used, or a plurality of these methods can be used in combination.

  The eye detection unit 10 determines whether or not an approximately elliptical object regarded as an iris or a pupil is captured in the eye image captured by the capturing unit 2, and the elliptical object is captured. Is output to the authentication processing unit 17. As a determination method in the eye detection unit 10, for example, a pattern matching method can be used. Further, in order to reduce the calculation amount, the eye image is binarized and the like, or the position that looks like a pupil or iris in advance. It is also possible to use a method of determining the ellipse by performing detailed contour extraction on the identified portion to detect the pupil or iris contour, performing ellipse approximation on the detected contour, Good. As for the method of ellipse approximation, for example, ellipse approximation can be performed using the least square method, but it goes without saying that the present invention is not limited to this method.

  The authentication processing unit 17 detects, from the image output from the capture processing unit 3, an iris detection unit 11 that detects an iris portion, and an image of a substantially elliptical iris portion detected by the iris detection unit 11 as a circular iris. A circular correction unit 12 that corrects an image, an authentication information generation unit 19 that generates authentication information from an iris image corrected to be circular by the circular correction unit 12 using a predetermined method, and registration of a person registered in advance A storage unit 21 in which authentication information is stored, a verification unit 20 for comparing and verifying registered authentication information stored in the storage unit 21 and authentication information created by the authentication information creation unit 19, and a comparison verification of the verification unit 20 It has the authentication result determination part 22 which determines whether the to-be-authenticated person 30 is a person registered beforehand by a result.

  In addition, each component of the authentication processing unit 17, that is, a method for creating authentication information in the authentication information creating unit 19, a method for collating in the collating unit 20, and a method for judging the authentication result in the authentication result judging unit 22 are publicly known. Although various iris authentication methods, for example, the method described in Patent Document 1, can be used, the present invention is not limited to this method.

  The iris detection unit 11 of the authentication device 1 according to the first embodiment of the present invention uses an eye image output from the eye detection unit 10 and forms an iris that is regarded as an elliptical iris from the image. Cut out the image. Regarding the iris image cutout method, when the pupil shape detected by the eye detection unit 10 is clear, a pattern similar to the elliptical shape of the pupil is generated, and the iris contour is detected by performing pattern matching. The outline range may be cut out, or the iris outline may be detected using the luminance difference between the white eye and the iris, and the outline range may be cut out.

  FIG. 3 is a diagram for explaining the processing of the iris detection unit 11 of the authentication device 1 according to the first embodiment of the present invention. FIG. 3A illustrates the pupil, iris, and white eye in the eye image. FIG. 3B, FIG. 3C, and FIG. 3D are diagrams for explaining the relationship between luminance values, and FIG. 3B is an example of a scanning direction when detecting an iris contour using a luminance threshold value. FIG. First, as shown in the upper part of FIG. 3A, it is assumed that the white image 392, the iris 90, and the pupil 92 are captured in the eye image. In this case, as shown in the lower part of FIG. 3A, the luminance value of the iris 90 portion is higher than the luminance value of the pupil 92 portion, and the luminance value of the white eye 392 portion is the luminance value of the iris 90 portion. Even higher than. Therefore, the iris detection unit 11 provides the threshold th1 and compares the luminance value of the pixel with the threshold th1 while scanning the eye image, so that the portion of the white eye 392, the iris 90, and the pupil 92 are included in the eye image. It is possible to extract a contour point with the part. As shown in FIGS. 3 (b), 3 (c) and 3 (d), the scanning direction of the iris contour point extraction by the iris detection unit 11 is horizontal scanning, vertical scanning or It can be performed by any method of scanning in the radial direction. Here, examples of horizontal scanning, vertical scanning, and radiation scanning are shown, but the present invention is not limited to these examples with respect to the scanning direction of the iris contour detection method.

  Further, the iris detection unit 11 performs ellipse approximation by the method of least squares using the detected contour point as a reference, and calculates the center coordinates, rotation angle, and oblateness of the ellipse. Lagrange's undetermined coefficient method can be used as an elliptical approximation method by the method of least squares.

  Next, the circular correction unit 12 of the authentication device 1 according to the first embodiment of the present invention causes the iris detection unit 11 to convert the ellipse calculated by the ellipse approximation into a circular shape. Here, the function of the circular correction unit 12 of the authentication device 1 according to the first embodiment of the present invention will be described in detail. FIG. 4 is a diagram for explaining the function of the circular correction unit 12 of the authentication device 1 according to the first embodiment of the present invention. FIG. 4A is detected from the eye image by the iris detection unit 11. FIG. 4B is a diagram showing an example of an image of an elliptical iris 90. FIG. 4B is a diagram showing an example of an image obtained by rotationally correcting the image of the elliptical iris 90 shown in FIG. 4 (c) is a diagram illustrating an example of an image of the iris 190 corrected to a circular shape from the image of the iris 90 corrected for rotation shown in FIG. 4 (b).

  In the circular correction unit 12 of the authentication device 1 according to the first embodiment of the present invention, as shown in FIG. 4A, the X coordinate and the Y coordinate are defined in the eye image, and the elliptical iris is formed. The angle formed by the direction of the major axis of 90 with respect to the direction of the Y coordinate is calculated as the rotation angle θR, and when the minor axis S and the major axis L are taken, the value obtained by dividing the minor axis S by the major axis L is the flatness ratio H = Calculated as (S / L). Further, the circular correction unit 12 determines an area of the rectangular partial image 100 including the elliptical iris 90 and having the coordinates (x1, y1) as the center. Next, the circular correction unit 12 converts the previously determined partial image 100 so that the rotation angle θR becomes “0” as shown in FIG. 4B, that is, the major axis L in the direction of the Y coordinate. In addition, the position of the partial image 100 is determined so that the center of the partial image 100 is positioned at a predetermined coordinate (x2, y2) (hereinafter, this process is also referred to as a process for correcting the standard shape). Write down). Then, as shown in FIG. 4C, the circular correcting unit 12 has an iris 90 with a circular shape, that is, an iris with a flatness ratio H = 1.0, with the coordinates (x2, y2) as the center. The shape of the partial image 100 is corrected so as to be 190 and is output to the authentication information creation unit 19. As an image correction method by the circular correction unit 12, for example, the elliptical iris 90 is formed into a circular shape by enlarging the partial image 100 in the horizontal direction in FIG. The iris 190 can be corrected. As a method for enlarging the partial image 100, for example, an enlargement method such as a bicubic method can be used, but the present invention is not limited to this method.

  Next, the authentication information creation unit 19 of the authentication device 1 according to the first embodiment of the present invention uses the image of the circular iris 190 output from the circular correction unit 12 to perform encoding by a predetermined method. Authentication information is created and output to the collation unit 20.

  In addition, registration authentication information of a person registered in advance is stored in the storage unit 21 of the authentication device 1 according to the first embodiment of the present invention.

  Further, in the verification unit 20 of the authentication device 1 according to the first embodiment of the present invention, the dissimilarity between the authentication information created by the authentication information creation unit 19 and the registered authentication information stored in the storage unit 21. (For example, Hamming distance) is calculated, and the result is output to the authentication result determination unit 22.

  Next, in the authentication result determination unit 22 of the authentication device 1 according to the first exemplary embodiment of the present invention, the authentication information calculated by the verification unit 20 and stored in the storage unit 21 is stored in the authentication information generation unit 19. From the dissimilarity value with the registered authentication information, a comparison with a predetermined threshold is performed to determine whether or not the person 30 to be authenticated can be authenticated in advance, and the result (for example, , “Authentication possible” or “authentication impossible”) is output to the output unit 23.

  Further, as the output unit 23 of the authentication device 1 according to the first embodiment of the present invention, for example, a known display device using a liquid crystal, an EL, or the like can be used, or the user 30 is authenticated by voice. It is possible to use various devices such as a device that can notify a result or the like, or a device that can output information such as an authentication result to an externally connected device.

  Here, according to the authentication device 1 in the first embodiment of the present invention, the circular correction unit 12 corrects an image of the elliptical iris 90 obtained by capturing the person 30 to be authenticated by the photographing unit 2 from an oblique direction. The reason why the iris authentication process can be performed by using the circular iris 190 image obtained by processing will be described. FIG. 5 is a diagram for explaining the reason why the iris authentication process can be performed by the authentication device 1 according to the first embodiment of the present invention. FIG. 5 (a) shows the planar structure of the eye 31 of the living body. FIG. 5B is a diagram showing a cross-sectional structure of the living eye 31.

  First, as shown in FIG. 5A, the eyeball 70 of the living eye 31 has a substantially spherical shape, and when viewed from the front, the pupil 72 exists inside the circular iris 71. Yes. Further, as shown in FIG. 5B, the cross section of the living eye 31 has an iris 71 formed in the eyeball 70 of the living eye 31 in the form of a diaphragm in the camera device. A gap portion of the iris 71 forms a pupil 72. Accordingly, the iris 71 is considered to have a substantially planar shape, and the image of the elliptical iris 90 obtained by photographing from an oblique direction does not have a portion lacking information on the iris eyelid pattern. It is possible to create an image having the same amount of information as the image of the iris 71 photographed in front of the eye 31 of the living body by correcting the image to the circular iris 190 by the geometric correction. Therefore, according to the authentication device 1 in the first embodiment of the present invention, the iris authentication process is performed using the image of the circular iris 190 obtained by correcting the image of the elliptical iris 90 photographed from the oblique direction. It is possible.

  Next, the function of the biometric determination unit 13 in the authentication device 1 according to the first embodiment of the present invention will be described in detail. The biometric determination unit 13 in the authentication device 1 according to the first embodiment of the present invention determines whether or not the person to be authenticated 30 is a living body from the image cut out by the iris detection unit 11 by a method described later. The result is output to the output unit 23.

  Here, the reason why the authentication apparatus 1 according to the first embodiment of the present invention can determine whether or not the person to be authenticated 30 as the subject is a living body will be described. FIGS. 6 and 7 are diagrams for explaining the reason why the authentication apparatus 1 according to the first embodiment of the present invention can perform biometric discrimination.

  FIG. 6A is a front view for explaining the configuration of the living eye 31 in the first embodiment of the present invention, and FIG. 6B is a cross-sectional view thereof. FIG.6 (c) is a front view for demonstrating the structure of the false eye 80 in the 1st Embodiment of this invention, FIG.6 (d) is the sectional arrow view.

  As shown in FIGS. 6A and 6B, the living eye 31 has a substantially spherical shape, and when viewed from the front, as shown in FIG. A pupil 72 is present inside the iris 71 of FIG. As shown in FIG. 6B, the cross section of the living eye 31 has an iris 71 formed in the eyeball of the living eye 31 in the form of a diaphragm in the camera device. The gap portion is the pupil 72.

  On the other hand, the fake eye 80 assumed as a counterfeit in the first embodiment of the present invention prints the iris 81 and the pupil 82 of the same pattern as the living eye 31 on a spherical body such as a resin, or wears a contact lens. And so on. As shown in FIG. 6C, when the false eye 80 is viewed from the front, it is difficult to distinguish from the eye 31 of the living body. However, as shown in FIG. Unlike the living eye 31, 81 and the pupil 82 are attached not to the inside of the eyeball but to the surface. The authentication device 1 according to the first embodiment of the present invention uses this difference to determine whether the subject is the living eye 31 or the false eye 80. This determination method will be further described.

  FIG. 7A is a diagram for explaining a living eye 31 photographed from an oblique direction by the authentication device 1 according to the first embodiment of the present invention, and FIG. 7B is a diagram illustrating the present invention. It is a figure for demonstrating the false eye 80 image | photographed from the diagonal direction by the authentication apparatus 1 in this 1st Embodiment.

  As shown in FIG. 7A, since the iris 71 of the living eye 31 is configured inside the eyeball, the pupil 72 and the iris 71 have the same focal position even when taken obliquely. It was confirmed that it exhibits a symmetrical elliptical shape.

  On the other hand, as shown in FIG. 7B, in the false eye 80, the iris 81 is attached to the surface of the sphere. In the right region, there is a region where a part of the iris 81 is hidden by the pupil 82 and the pattern on the iris 81 becomes invisible. The shape of the visible part of the iris 81 is not an elliptical shape, but is formed from arcs having two different curvatures (the arc 180 of the sphere of the false eye 80 on the right side and the arc 181 of the iris 81 on the left side of the iris 81). It becomes the shape to be done.

  The biometric determination unit 13 of the authentication device 1 according to the first embodiment of the present invention uses the difference in the shape of the visible portion of the iris 81 to determine whether the person to be authenticated 30 is a living body. . In other words, the outer shape of the shape of the portion that is regarded as an iris detected by the iris detection unit 11 is measured, and if the outer shape is an elliptical shape, it is determined that the subject is the eye 31 of the living body. When the outer shape of the shape of the portion that is regarded as the iris detected by the detection unit 11 is not an elliptical shape, but is a shape composed of arcs 180 and 181 having two different curvatures, the subject is the false eye 80. Judge that there is.

  The determination result of whether the subject in the biometric determination unit 13 of the authentication device 1 according to the first embodiment of the present invention is the living eye 31 or the fake eye 80 is sent to the output unit 23, and the output unit 23, the person to be authenticated 30 may be informed, or if it is determined that the subject is the false eye 80, an alarm may be issued.

  When the living body determination unit 13 determines that the subject is the living body eye 31, the signal is also sent to the iris detection unit 11, and the iris detection unit 11 is regarded as an elliptical iris 71. This image is sent to the circular correction unit 12, and as described above, the circular correction unit 12 corrects the image of the portion regarded as the elliptical iris 71 into a circular shape. FIG.7 (c) is a figure which shows an example of the image of the iris 71 correct | amended in the circular shape in the circular correction | amendment part 12 of the authentication apparatus 1 in the 1st Embodiment of this invention. As shown in FIG. 7C, the portion regarded as the iris 71 detected by the iris detecting unit 11 is corrected to a circular shape by the circular correcting unit 12, and authentication information is obtained by using this image 95. The creation unit 19 can create authentication information.

  Further, as described above, in the authentication device 1 according to the first embodiment of the present invention, the verification unit 20 performs verification processing using the authentication information generated by the authentication information generation unit 19, and the authentication result determination unit 22. Determines the authentication result and outputs it to the output unit 23.

  Even when the subject is the false eye 80 and an image that is regarded as the iris 81 is detected by the iris detection unit 11, it is regarded as the iris 81 according to the authentication device 1 in the first embodiment of the present invention. In the image, the pattern information of the eyelids of the iris 81 is missing, and even if such an image is used, authentication information is not created by the authentication information creation unit 19 after all, or the verification unit In the collation process at 20, the authentication information of the person to be subjected to “spoofing” does not match, so even in such a case, the authentication cannot be performed. As a result, “spoofing” by the false eye 80 can be excluded. it can.

  Here, the operation of the authentication device 1 according to the first embodiment of the present invention will be described. FIG. 8 is a flowchart showing operation steps of the authentication device 1 according to the first embodiment of the present invention.

  As shown in FIG. 8, in the authentication device 1 according to the first embodiment of the present invention, the control unit 6 turns on the light source unit 7 and irradiates the eye 31 of the person 30 to be authenticated (S1).

  Next, the control unit 6 causes the photographing unit 2 to photograph the eye 31 of the person 30 to be authenticated (S2).

  Next, the control unit 6 causes the capture processing unit 3 to perform the above-described capture processing (S3).

  If the capture processing unit 3 can capture the image, the process proceeds to the next step. If the capture processing cannot be performed, the process returns to step S2 again, and the control unit 6 causes the photographing unit 2 to capture the subject. Shooting is performed (S4).

  In step S4, when the capture processing unit 3 performs image capture processing, the iris detection unit 11 detects a portion regarded as an iris from the image sent from the capture processing unit 3 (S5).

  Next, in step S5, the living body discrimination unit 13 determines whether or not the portion regarded as the iris detected from the image detected by the iris detection unit 11 has an elliptical shape (S6). In some cases, it is determined that the subject is the living eye 31 (S7). On the other hand, when the portion detected as the iris detected by the iris detection unit 11 is not elliptical, the living body determination unit 13 determines that the subject is not the eye 31 of the living body and outputs the result to the output unit 23. Then, the result is notified to the person 30 to be authenticated from the output unit 23 (S9).

  In step S6, when the living body determination unit 13 determines that the subject is the eye 31 of the living body, a signal indicating that is sent to the iris detection unit 11, and the iris detection unit 11 is a portion that is regarded as an iris. Are sent to the circular correction unit 12, the circular correction processing of the image by the circular correction unit 12, the authentication information generation processing by the authentication information generation unit 19, and the comparison with the registered authentication information stored in the storage unit 21 in the verification unit 20. A verification process and an authentication result determination process in the authentication result determination unit 22 are performed, and the authentication result is notified to the person 30 to be authenticated through the output unit 23 (S8).

  As described above, according to the authentication device 1 in the first embodiment of the present invention, it is possible to determine whether the subject is the living eye 31 or the false eye 80 by a simple method. In the case of the living eye 31, the iris authentication process can be performed using the image.

  Note that in the authentication processing unit 17 of the authentication device 1 according to the first exemplary embodiment of the present invention, the circular correction unit 12 converts the elliptical iris 90 image detected by the iris detection unit 11 into a circular shape. The example in which the authentication information creation unit 19 creates authentication information from the image of the iris 190 corrected to the iris 190 and corrected to the circular shape has been shown. However, the biometric device and the authentication device of the present invention are limited to this example. Is not to be done. For example, the configuration may be such that the authentication information creation unit 19 directly creates authentication information from the elliptical iris 90 detected by the iris detection unit 11, and the authentication process is performed using the authentication information. Needless to say.

  In such a case, the authentication information creation unit 19 performs polar coordinate conversion directly on the image of the elliptical iris 90 detected by the iris detection unit 11 to generate authentication information. As a code generation method after polar coordinate conversion in the authentication information creating unit, for example, the method described in Patent Document 1 can be used, but the method of polar coordinate conversion is different.

  FIG. 9 is a diagram for explaining another function of the authentication information creation unit 19 of the authentication device 1 according to the first embodiment of the present invention. FIG. FIG. 9B is a diagram showing line segments 110 to 125 in the polar coordinate system, and FIG. 9B corresponds to the line segments 110 to 125 of the circular iris 190 shown in FIG. It is the figure which showed the line segments 110-125.

  As shown in FIG. 9A, the contour of the iris 190 and the center point of the iris 190 are obtained for the image of the circular iris 190 obtained when the eye 31 of the person 30 to be authenticated is photographed from the front. The segment between the two is divided by a predetermined angle, line segments 110 to 125 connecting the outline of the pupil 192 and the outline of the iris 190 are set, and the set line segments are connected in the circumferential direction to polar coordinates Can be converted. Here, an example of dividing the region into 16 regions has been shown, but the present invention does not limit the degree of division in the circumferential direction for polar coordinate conversion. For example, it can be divided into 256 areas.

  Next, in the authentication device 1 according to the first embodiment of the present invention, the eye 31 of the person 30 to be authenticated is photographed from an oblique direction, so the iris 90 of the person 30 to be authenticated is shown in FIG. Thus, it becomes an elliptical shape. The authentication information creation unit of the authentication device 1 according to the first embodiment of the present invention flattens the elliptical iris 90 as shown in FIG. Using the line segments 110 to 125 corrected according to the rate H and the rotation angle θR, the image is divided into 16 regions. By this processing, it is possible to perform polar coordinate conversion equivalent to that performed on the circular iris 190 shown in FIG. Note that the contour of the pupil 92 and the contour of the iris 90 and the line segments 110 to 125 when the region is divided are the oblateness H and the rotation angle θR of the elliptical iris 90 detected by the iris detection unit 11, and the iris. It can be determined from the coordinates of the 90 images.

(Second Embodiment)
Next, the configuration of the authentication device 99 in the second embodiment of the present invention will be described. FIG. 10 is a diagram for explaining a usage pattern of the authentication device 99 according to the second embodiment of the present invention, and FIG. 11 is a function showing a configuration of the authentication device 99 according to the second embodiment of the present invention. It is a block diagram.

  First, as shown in FIG. 10, the authentication device 99 according to the second embodiment of the present invention is different from the authentication device 1 according to the first embodiment of the present invention in the direction of the line of sight of the person 30 to be authenticated. On the other hand, it can be used in a state of being directly opposed.

  Further, as shown in FIG. 11, the authentication device 99 according to the second embodiment of the present invention is different from the authentication device 1 according to the first embodiment of the present invention in that the direction of the line of sight of the person 30 to be authenticated is changed. A line-of-sight guiding unit 69 for guiding is provided, and a living body determining unit 65 is provided instead of the living body determining unit 13. The other components are the same as those of the authentication device 1 in the first embodiment, and thus the description thereof is omitted.

  As shown in FIG. 11, the biometric determination unit 65 of the authentication device 99 according to the second embodiment of the present invention determines the position of the iris from the image of the portion regarded as the iris detected by the iris detection unit 11. In the iris position determination unit 62, the pupil position determination unit 63 that determines the position of the pupil from the image of the portion that is regarded as the iris detected by the iris detection unit 11, and the iris position determination unit 62 and the pupil position determination unit 63 From the determined result, it is determined whether or not the subject is a living body, and the living body determining unit 64 that outputs the result to the iris detecting unit 11 is provided.

  In the authentication device 99 according to the second embodiment of the present invention, the line-of-sight guide unit 69 causes the line-of-sight direction of the person 30 to be authenticated to be at a predetermined angle (with respect to the optical axis direction Z of the imaging unit 2 of the authentication device 99). The line of sight of the person 30 to be authenticated is guided so as to have about 40 ° to about 80 °. As the configuration of the line-of-sight guide unit 69 and the method of line-of-sight guidance, for example, a configuration in which the direction in which the line of sight should be moved is indicated by the direction of the arrow with respect to the person 30 to be authenticated, or the direction in which the line of sight should be moved by voice. Various known configurations or methods such as an instruction method can be used, but the present invention is not limited to this configuration or method for visual line guidance.

  Here, the configuration of the false eye 290 assumed by the authentication device 99 according to the second embodiment of this invention will be described in detail. FIG. 12 is a diagram for explaining the configuration of the false eye 290 assumed by the authentication device 99 according to the second embodiment of the present invention, and FIG. 12 (a) is a front view thereof. 12 (b) is a sectional view thereof.

  As shown in FIG. 12, the false eye 290 assumed in the second embodiment of the present invention is not “spoofed” inside the sphere like the living body eye 31 instead of the surface of the sphere. The iris 291 having the same pattern as the iris of the person 30 to be authenticated is provided, and the gap forms a pupil 292. The authentication device 99 according to the second embodiment of the present invention can eliminate such a fake eye 290 that is more elaborately forged in addition to the fake eye 80 assumed in the first embodiment. It is.

  Next, the reason why such a false eye 290 can be eliminated by using the authentication device 99 according to the second embodiment of the present invention will be described in detail. FIG. 13 is a diagram for explaining the reason why the authentication device 99 according to the second embodiment of the present invention can eliminate the false eye 290. FIG. 13A is a schematic diagram of an image taken by moving the eye 31 of the living body in an oblique direction by the authentication device 99 according to the second embodiment of the present invention, and FIG. It is a schematic diagram of the image at the time of image | photographing by moving the false eye 290 to the diagonal direction with the authentication apparatus 99 in the 2nd Embodiment of this invention.

  As shown in FIG. 13 (a), when an image is taken with the authentication device 99 according to the second embodiment of the present invention in which the eye 31 of the living body is guided in an oblique direction, the eye 31 of the living body. Among these, the center position P of the iris 71 portion, that is, the position where the center line of the elliptical width in the minor axis direction intersects the center line of the major axis width is the center position S of the pupil 72 portion, ie, the ellipse. It differs from the position where the center line of the width in the minor axis direction of the shape and the center line of the width in the major axis direction intersect. Specifically, as illustrated in FIG. 13A, when the person 30 to be authenticated moves his / her line of sight to the left (toward the right), the center of the pupil 72 rather than the center position P of the iris 71. The position S is located at a position closer to the center (left side in FIG. 13A).

  On the other hand, in the false eye 290, the shift of the center position P of the iris 71 and the center position S of the pupil 72 as occurred in the living eye 31 does not occur, and as shown in FIG. The center position P of the iris 291 and the center position S of the pupil 292 coincide.

  Thus, there is a difference in the positional relationship between the center position P of the irises 71 and 291 and the center position S of the pupils 72 and 292 between the living eye 31 and the false eye 290.

  In the authentication device 99 according to the second embodiment of the present invention, between the center position P of the irises 71 and 291 and the center position S of the pupils 72 and 292 between the living eye 31 and the false eye 290. Using the difference in positional relationship, it is determined whether the subject is the living eye 31 or not. Specifically, the center position P of the irises 71 and 291 is detected by the iris position determination unit 62 from the image of the portion regarded as the iris detected by the iris detection unit 11, and the pupil 72 is detected by the pupil position determination unit 63. 292, and the biometric determination unit 64 determines whether the center position P and the center position S are misaligned. When it is determined that the center position P of the irises 71 and 291 and the center position S of the pupils 72 and 292 do not coincide with each other, the living body determination unit 64 determines that the subject is the eye 31 of the living body. If it is determined that P and the center position S match, it is determined that the subject is the false eye 290. Regarding the position determination between the center position P and the center position S in the living body determination unit 64, a predetermined threshold value is provided for the difference, and if the difference between the center position P and the center position S is within the predetermined threshold value, they match. Then, it can be determined.

  As described above, by using the authentication device 99 according to the second embodiment of the present invention, it is possible to determine whether the subject is the living eye 31 or the false eye 290.

  It should be noted that by using the authentication device 99 in the second embodiment of the present invention, the false eye 80 described in the first embodiment also has the center position P of the iris 81 similar to the false eye 290. Since the center position S of the pupil 82 matches, it is possible to determine whether or not the eye 31 is a living body.

  Here, the operation of the authentication device 99 in the second embodiment of the present invention will be described. FIG. 14 is a flowchart for explaining the operation steps of authentication apparatus 99 in the second embodiment of the present invention.

  As shown in FIG. 14, in the authentication device 99 according to the second embodiment of the present invention, first, the control unit 6 irradiates the light source unit 7 with light rays to the eye 31 of the person 30 to be authenticated, and the line of sight. The guidance unit 69 is guided to move the direction of the line of sight of the eye 31 of the person 30 to be authenticated in a predetermined direction (for example, a direction toward the outside) (S10).

  Next, similarly to the authentication device 1 in the first embodiment, the processing from step S2 to step S5 is performed.

  In step S5, when the iris detection unit 11 detects an elliptical iris, the iris position determination unit 62 detects the above-mentioned iris center position P from the image (S11), and the pupil position determination unit 63 The center position S of the pupil is detected (S12), and the living body determination unit 64 compares the center position P of the iris with the center position S of the pupil (S13, S14).

  When the living body determination unit 64 determines that the iris center position P and the pupil center position S do not match, the living body determination unit 64 determines that the subject is the eye 31 of the living body (S15). On the other hand, when it is determined that the center position P of the iris and the center position S of the pupil coincide with each other, the living body determination unit 64 determines that the subject is not a living body (S16). The result of the biometric determination of the subject by the biometric determination unit 64 is sent to the iris detection unit 11, and when it is determined that the subject is the eye 31 of the living body, it is an iris detected by the iris detection unit 11. The circular correction processing of the considered portion is performed by the circular correction unit 12, the authentication information generation unit 19 generates authentication information, the verification unit 20 performs comparison and verification processing with the registered authentication information stored in the storage unit 21, and authentication result determination An authentication result determination process in the unit 22 is performed (S8).

  As described above, according to the authentication device 99 of the second embodiment of the present invention, the iris 31 is discriminated between the living eye 31 and the false eye 290 and the subject determined to be the living eye 31 is iris. Authentication processing can be performed.

  In the authentication apparatus 99 according to the second embodiment of the present invention, the biometric determination unit 65 has been described with an example in which the iris position determination unit 62 and the pupil position determination unit 63 perform processing in this order. The order is not limited to this order, and it goes without saying that the configuration may be such that the pupil position determination unit 63 and the iris position determination unit 62 perform processing in this order, or the processing may be performed simultaneously.

  Furthermore, in the authentication devices 1 and 99 according to the embodiment of the present invention, each function block of the authentication processing unit 17 may be realized by software or hardware such as a dedicated circuit. It may be. When each function is realized by software, the iris authentication apparatus and the iris authentication method of the present invention can be realized by writing a program capable of realizing the function of each component and causing the computer to execute the program. It goes without saying that the biometric discrimination device, the authentication device, and the biometric discrimination method of the present invention can be realized in other computers by storing these programs in a storage medium and causing other computers to execute the programs.

  Further, although the authentication apparatuses 1 and 99 in the embodiment of the present invention have been described as performing the iris authentication process, the authentication apparatus of the present invention is not limited to the iris authentication method. . For example, it goes without saying that biometric authentication methods such as retina authentication and face authentication can be used as appropriate.

  As described above, according to the present invention, it is possible to provide a biometric identification device and an authentication device that can effectively perform biometric discrimination on a spherical counterfeit similar to a living eye such as a false eye. The biometric determination device that determines whether or not the subject is a living body, the authentication device that performs personal authentication of the subject, and the determination whether or not the subject is a living body It is useful as a living body discrimination method.

The figure which shows the usage pattern of the authentication apparatus in the 1st Embodiment of this invention. 1 is a functional block diagram showing the configuration of an authentication device according to the first embodiment of the present invention. The figure for demonstrating the process of the iris detection part of the authentication apparatus in the 1st Embodiment of this invention. The figure for demonstrating the function of the circular correction | amendment part of the authentication apparatus in the 1st Embodiment of this invention. The figure for demonstrating the reason an iris authentication process is possible by the authentication apparatus in the 1st Embodiment of this invention. (A) is a front view for demonstrating the structure of the biological eye in the 1st Embodiment of this invention. (B) is for demonstrating the structure of the biological eye in the 1st Embodiment of this invention. The sectional view (c) is a front view for explaining the configuration of the false eye in the first embodiment of the present invention. The front view (d) explains the configuration of the false eye in the first embodiment of the present invention. Cross-sectional arrow view for (A) is a figure for demonstrating the eye of the biological body image | photographed from the diagonal direction by the authentication apparatus in the 1st Embodiment of this invention, (b) is diagonal by the authentication apparatus in the 1st Embodiment of this invention. FIG. 8C is a diagram for explaining an example of an iris image corrected to a circular shape in the circular correction unit of the authentication device according to the first embodiment of the present invention. The flowchart which shows the operation | movement step of the authentication apparatus in the 1st Embodiment of this invention. The figure for demonstrating another function of the authentication information preparation part of the authentication apparatus in the 1st Embodiment of this invention The figure for demonstrating the usage type of the authentication apparatus in the 2nd Embodiment of this invention. Functional block diagram showing the configuration of the authentication device according to the second embodiment of the present invention (A) is a front view for explaining the configuration of the false eye assumed by the authentication device according to the second embodiment of the present invention, and (b) is assumed by the authentication device according to the second embodiment of the present invention. Sectional drawing for demonstrating the structure of the false eye which is doing (A) is a schematic diagram of an image taken by moving the eyes of a living body in an oblique direction with the authentication device according to the second embodiment of the present invention, and (b) is an authentication device according to the second embodiment of the present invention. Schematic diagram of the image when the fake eye is moved obliquely with The flowchart for demonstrating the operation | movement step of the authentication apparatus in the 2nd Embodiment of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1,99 Authentication apparatus 2 Imaging | photography part 3 Capture process part 6 Control part 7 Light source part 9 Image quality determination part 10 Eye detection part 11 Iris detection part 12 Circular correction part 13,65 Living body discrimination part 17 Authentication process part 19 Authentication information creation part 20 Verification unit 21 Storage unit 22 Authentication result determination unit 23 Output unit 30 Person to be authenticated 31 Eye 62 Iris position determination unit 63 Pupil position determination unit 64 Biological determination unit 69 Gaze guidance unit 70 Eyeball 71, 81, 90, 190, 291 Iris 72 , 82, 92, 192, 292 Pupil 80, 290 False eye 95 Image 100 Partial image 110-125 Line segment 180, 181 Arc 392 White eye

Claims (12)

A photographing unit for photographing the subject's eyes from an oblique direction with respect to the line-of-sight direction;
A living body discrimination device comprising: a living body discrimination unit that discriminates whether or not the subject is a living body based on an eye image of the subject photographed by the photographing unit. An iris detection unit for detecting an iris image from the image of the eye of the subject photographed by the photographing unit;
The said biological body discrimination | determination part discriminate | determines whether the said to-be-photographed object is a biological body by whether the said iris image detected by the said iris detection part is elliptical shape. Biological discrimination device. The living body discriminating apparatus according to claim 2, wherein the living body discriminating unit discriminates that the subject is a living body when the iris image detected by the iris detecting unit has an elliptical shape. A line-of-sight guidance unit for guiding the subject to move the line of sight;
An iris detection unit for detecting an iris image from the eye image of the subject photographed by the photographing unit;
A pupil detection unit that detects a pupil image from an image of the eye of the subject imaged by the imaging unit;
The photographing unit photographs the eye in a state where the line of sight of the subject is guided,
The living body determination unit determines whether the subject is a living body based on a positional relationship between an iris image detected by the iris detection unit and a pupil image detected by the pupil detection unit. The living body discrimination apparatus according to claim 1, wherein The living body determination unit determines that the subject is not a living body when the center position of the iris image detected by the iris detection unit matches the center position of the pupil image detected by the pupil detection unit. The living body discrimination apparatus according to claim 4. The living body discrimination apparatus according to any one of claims 1 to 5, further comprising a light source unit that irradiates a region including at least eyes of the subject. The living body discrimination apparatus according to any one of claims 1 to 6, further comprising an image quality determination unit that determines an image quality of an image captured by the imaging unit. The living body discrimination apparatus according to claim 1, further comprising an eye detection unit that detects an eye from an image captured by the imaging unit. The living body discrimination device according to claim 3,
A circular correction unit for correcting the elliptical iris image detected by the iris detection unit into a circular shape;
An authentication apparatus, comprising: an authentication processing unit that performs authentication processing of the subject using an iris image that has been corrected to a circular shape by the circular correction unit. The living body discrimination device according to claim 3,
An authentication apparatus comprising: an authentication processing unit that performs authentication processing of the subject using the elliptical iris image detected by the iris detection unit. A first step of photographing the eye of the subject from an oblique direction with respect to the line-of-sight direction;
A biological discrimination method comprising: a second step of discriminating whether or not the subject is a living body based on the eye image of the subject photographed in the first step. On the computer,
A first step in which an image obtained by photographing an eye of a subject from a direction oblique to the line-of-sight direction is input;
And a second step of determining whether or not the subject is a living body based on the eye image of the subject input in the first step.

Images