JP2007011667A - Iris authentication device and iris authentication method - Google Patents

Abstract

There is no need to photograph the subject's eyes from the front, and the subject's line of sight is guided toward the camera, or the camera is arranged to face the subject's eyes. And an iris authentication device and an iris authentication method that do not require various devices.
An imaging unit that captures an eye of a person to be authenticated from an oblique direction, an iris detection unit that detects an elliptical iris image from an image captured by the imaging unit, and an iris detection unit that detects the eye. A circular correction unit 12 that corrects the elliptical iris image thus formed into a circular shape, and an authentication processing unit 17 that performs authentication processing of the person to be authenticated using the iris image corrected by the circular correction unit 12 into a circular shape. It was.
[Selection] Figure 2

Description

  The present invention relates to an iris authentication apparatus and an iris authentication method for performing personal authentication using an image of at least an iris portion of a person to be authenticated.

  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.
Japanese Patent No. 3307936

  However, in the iris authentication method as described above, it is necessary to photograph the iris so that the iris is circular when encoding, and thus it is necessary to photograph the eye of the person to be authenticated from the front. For this reason, there is a problem that it is necessary to devise various means such as guiding the line of sight of the person to be authenticated toward the camera or arranging the camera to face the person to be authenticated. .

  The present invention has been made in view of such problems, and it is not necessary to photograph the person to be authenticated from the front, guiding the line of sight of the person to be authenticated toward the camera, It is an object of the present invention to provide an iris authentication device and an iris authentication method that do not require various arrangements such as being arranged in the direction of the eye of the authenticator.

  The iris authentication apparatus according to the present invention performs authentication processing of a person to be authenticated by using an image capturing unit that captures an eye of the person to be authenticated from an oblique direction and an image of at least a portion of the image captured by the image capturing unit. And an authentication processing unit.

  According to such a configuration, the authentication processing unit can perform authentication processing using an image taken by the photographing unit and photographed from the oblique side of the person to be authenticated. Iris that does not need to be photographed from the camera and that does not require various ingenuity such as guiding the subject's line of sight toward the camera or arranging the camera to face the subject's eyes An authentication device can be provided.

  Moreover, the structure provided with the iris detection part which detects an elliptical iris image from the image image | photographed by the imaging | photography part may be sufficient.

  According to such a configuration, since the iris detection unit can detect an elliptical iris image, it is possible to realize a configuration in which authentication processing can be easily performed using the detected iris image.

  Furthermore, a circular correction unit that corrects the elliptical iris image detected by the iris detection unit into a circular shape is provided, and the authentication processing unit uses the iris image that has been corrected to a circular shape by the circular correction unit. It may be configured to perform authentication processing.

  According to such a configuration, since the elliptical iris image can be corrected to a circular shape, it is possible to authenticate even using an image photographed from an oblique direction by using the circular corrected image. A configuration that facilitates processing can be realized.

  The authentication processing unit includes an authentication information generating unit that generates authentication information from an iris image corrected to a circular shape, authentication information generated by the authentication information generating unit, and registered authentication information of a person registered in advance. The structure provided with the collation part to compare and collate may be sufficient.

  According to such a configuration, since authentication information can be created from an iris image corrected to a circular shape, a configuration that facilitates authentication processing even using an image taken from an oblique direction is realized. can do.

  Further, the authentication processing unit is registered in advance with an elliptical authentication information creating unit that creates authentication information from the elliptical iris image detected by the iris detecting unit, and authentication information created by the elliptical authentication information creating unit. A configuration may be provided that includes a collation unit that compares and collates the registered authentication information of each person.

  According to such a configuration, it is possible to realize a configuration capable of performing authentication processing even using an image photographed from an oblique direction using the authentication information created by the elliptical authentication information creation unit.

  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, an authentication process is further performed on an image that is determined to have good image quality by the image quality determination unit, so that a configuration with few errors can be realized.

  Moreover, the structure provided with the eye detection part which determines whether the eye was image | photographed by the image image | photographed with the imaging | photography part may be sufficient.

  According to such a configuration, an authentication process can be performed on an image for which it has been determined that the eye has been detected by the eye detection unit, so that a configuration with few errors can be realized.

  Further, the eye detection unit may be configured to determine whether or not an oval eye is captured in the image captured by the imaging unit.

  According to such a configuration, the eye detection unit further detects an elliptical eye, so that a configuration suitable for photographing the person to be authenticated from an angle and performing authentication processing from the eye image is realized. Can do.

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

  According to such a configuration, it is possible to realize a configuration in which the iris pattern of the person to be authenticated is photographed with high contrast.

  Further, the photographing unit may have a plurality of photographing devices that photograph the verifier's eyes from an oblique direction.

  According to such a structure, the structure which increases the opportunity which can image | photograph a to-be-authenticated person's favorable eye image is further realizable by using a some imaging device.

  Further, the plurality of imaging devices may be configured to be imaging devices having different resolutions.

  According to such a configuration, since an eye image is captured by imaging devices having different resolutions, it is possible to realize a configuration that increases the chance of capturing an eye image having the number of pixels that can be authenticated.

  The plurality of imaging devices may be configured as imaging devices having different imaging magnifications.

  According to such a configuration, since an eye image is captured by imaging devices having different imaging magnifications, it is possible to realize a configuration that increases the chances of capturing an eye image that is sufficiently enlarged to perform authentication processing. .

  In addition, when the angle formed by the gaze direction detection unit that detects the gaze direction of the person to be authenticated and the gaze direction detected by the gaze direction detection unit and the shooting direction of the shooting unit exceeds a predetermined angle, shooting is performed. The control part which stops the process of a part or an authentication process part may be sufficient.

  According to such a configuration, it is possible to perform eye image capturing or authentication processing when the angle formed by the direction of the line of sight of the person to be authenticated and the capturing direction of the capturing unit is within a predetermined angle. A configuration capable of performing an accurate authentication process can be realized.

  Next, the iris authentication method of the present invention uses a first step of photographing the eye of the person to be authenticated from an oblique direction, and an image of a part including at least the iris of the image photographed in the first step. And a second step of performing authentication processing of the authenticator.

  According to such a method, since the authentication process can be performed in the second step using the image taken in the first step and the eye of the person to be authenticated taken obliquely, the eye of the person to be authenticated can be obtained. There is no need to shoot the camera from the front, and it is necessary to make various arrangements such as guiding the subject's line of sight toward the camera or arranging the camera to face the subject's eyes. There can be no iris authentication method.

  Next, the iris authentication program of the present invention includes a first step in which an image taken from an oblique direction of the eye of the person to be authenticated is input to a computer, and at least an iris of the image input in the first step. The second step of performing the authentication process of the person to be authenticated is executed using the image of the included portion.

  According to such a program, the authentication process can be performed in the second step using the image obtained by photographing the eye of the person to be authenticated obliquely input in the first step. There is no need to shoot the camera from the front, and it is necessary to make various arrangements such as guiding the subject's line of sight toward the camera or arranging the camera to face the subject's eyes. There can be no iris authentication program.

  As described above, according to the present invention, it is not necessary to photograph the subject's eyes from the front, and the user's eyes are directed toward the camera, or the camera is directed to the subject's eyes. Therefore, it is possible to provide an iris authentication device and an iris authentication method that do not need to be arranged in various directions.

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

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

  As shown in FIG. 1, the iris authentication device 1 according to the first embodiment of the present invention is oblique to the person to be authenticated 30 (in the front direction (Z-axis direction) of the person 30 to be authenticated in FIG. 1). The eye 31 of the person 30 to be authenticated is photographed by the photographing unit 2 from the direction having the angle θ with respect to the authentication, and the authentication of the person 30 to be authenticated is performed using an image of an elliptical iris portion among the photographed eye images. Processing can be performed.

  As described above, the iris authentication device 1 according to the first exemplary embodiment of the present invention does not need to be placed facing the person to be authenticated 30, so that the person to be authenticated 30 is aware of the existence of the iris authentication device 1. The iris authentication process can be performed without any problem.

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

  As shown in FIG. 2, the iris authentication device 1 according to the first exemplary embodiment of the present invention includes a light source unit 7 that irradiates the eye 31 of the person 30 to be authenticated, and a person to be authenticated that is irradiated by the light source unit 7. The image capturing unit 2 that captures an eye image including at least the iris of the 30 eyes 31, the image quality determination of the eye image captured by the image capturing unit 2, and the like, and the process of sending the image determined to be good to the authentication processing unit 17 ( Hereinafter, this processing is referred to as capture processing), the capture processing unit 3 that performs the iris authentication processing by a predetermined method using the image captured by the capture processing unit 3, and the authentication in the authentication processing unit 17 The output unit 23 that outputs the result to another external device or the like, or notifies the authentication result to the person 30 to be authenticated by sound or image, etc., and the light source unit 7, the imaging unit 2, the capture processing unit 3, and the authentication Each processing unit 17 And a control unit 6 for controlling the work.

  Hereinafter, each component of the iris authentication device 1 according to the first embodiment of the present invention will be described in detail.

  First, the light source unit 7 irradiates 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. Can be used.

  Further, the present invention is not limited in any way to the photographing unit 2, but as an example, a monochrome camera using a CCD can be used. The lens system mounted on the photographing unit 2 is preferably configured to include a telephoto lens that can magnify the region of the eye 31 for photographing.

  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 unit 9 determines the image quality by, for example, using the fact that an image with good image quality has a large amount of information of a predetermined high-frequency component, frequency-analyzing the image, and integrating the information amount of the predetermined high-frequency component. In addition, a method of determining that the higher the integrated value is, the better the image quality can be used. Besides, a method of comparing the luminance of the entire image with a predetermined threshold and evaluating the image quality based on the result, etc. Can also be used. Needless to say, these plural methods may 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. A method may be used in which a detailed contour extraction is performed on the identified portion to detect the pupil or iris contour, and an ellipse approximation is performed on the detected contour to determine an ellipse. . 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.

  Next, the authentication processing unit 17 detects an elliptical iris portion from the image output from the capture processing unit 3, and outputs the partial image output from the iris detection unit 11 and the iris detection unit 11. Authentication information is created using a predetermined method from a circular correction unit 12 that corrects a partial image of an elliptical iris to a circular iris image, and the iris image corrected to be circular by the circular correction unit 12 Authentication information creating unit 19, storage unit 21 storing registration authentication information of a person who has been registered in advance, and comparing and collating the registration information stored in storage unit 21 with the authentication information created by authentication information creating unit A verification unit 20 and an authentication result determination unit 22 that determines whether or not the person 30 to be authenticated is a person registered in advance based on the comparison verification result of the verification unit 20 and outputs the result to the output unit 23 are included. .

  Among the functions of each component of the authentication processing unit 17, a method for creating authentication information from a circular iris image in the authentication information creation unit 19, a verification method in the verification unit 20, and authentication in the authentication result determination unit 22 As a result determination method, for example, the method described in Patent Document 1 can be used. The present invention is not limited to this method, and various known authentication information creation methods, verification methods, and authentication result determination methods can be used.

  Here, the function of each component of the authentication processing unit 17 of the iris authentication apparatus 1 according to the first embodiment of the present invention will be described in detail.

  First, the iris detection unit 11 of the iris authentication apparatus 1 according to the first embodiment of the present invention uses the eye image output from the eye detection unit 10 and is regarded as an elliptical iris from the image. Cut out the iris image of the shape. 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 processing of the iris detection unit 11 of the iris authentication device 1 according to the first embodiment of the present invention, and FIG. 3A is a diagram illustrating pupils, irises, and white eyes in an eye image. 3 (b), 3 (c), and 3 (d) are examples of the scanning direction when the iris contour is detected using the luminance threshold value. FIG. First, as shown in the upper part of FIG. 3A, it is assumed that the white eye 92, the iris 90, and the pupil 91 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 91 portion, and the luminance value of the white eye 92 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 92 in the eye image, the iris 90, and the pupil 91 are compared. 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 iris authentication apparatus 1 according to the first embodiment of the present invention converts the ellipse calculated by the ellipse approximation into a circular shape in the iris detection unit 11. Here, the function of the circular correction unit 12 of the iris authentication apparatus 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 iris authentication apparatus 1 according to the first embodiment of the present invention. FIG. 4A is detected by the iris detection unit 11 from the eye image. FIG. 4B is a diagram illustrating an example of an image of the elliptical iris 90, and FIG. 4B is a diagram illustrating an example of an image obtained by rotationally correcting the image of the elliptical iris 90 illustrated in FIG. FIG. 4C 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.

  In the circular correction unit 12 of the iris authentication device 1 in the first exemplary embodiment of the present invention, as shown in FIG. 4A, the X coordinate and the Y coordinate are defined in the eye image, The angle formed by the direction of the major axis of the iris 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 = (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 iris authentication device 1 according to the first embodiment of the present invention encodes the image of the circular iris 190 output from the circular correction unit 12 by a predetermined method. The 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 iris authentication apparatus 1 according to the first embodiment of the present invention.

  Furthermore, in the collation unit 20 of the iris authentication device 1 according to the first exemplary embodiment of the present invention, the dissimilarity between the authentication information created by the authentication information creating unit 19 and the registered authentication information stored in the storage unit 21. The degree (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 iris authentication device 1 according to the first exemplary embodiment of the present invention, the authentication information generated by the verification information generation unit 19 and the storage unit 21 calculated by the verification unit 20 are stored. From the dissimilarity value stored with the registered authentication information, a comparison with a predetermined threshold is performed to determine whether or not the person to be authenticated 30 can be authenticated as a pre-registered person, and the result ( For example, “authentication possible” or “authentication impossible”) is output to the output unit 23.

  Moreover, as the output part 23 of the iris authentication apparatus 1 in the 1st Embodiment of this invention, the well-known display apparatus using a liquid crystal, EL, etc. can also be used, for example, and the to-be-authenticated person 30 is sounded. It is possible to use various devices such as a device that can notify an authentication 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 iris authentication device 1 in the first exemplary embodiment of the present invention, an image of the elliptical iris 90 obtained by photographing the person 30 to be authenticated by the photographing unit 2 from an oblique direction is displayed in the circular correction unit 12 as a circle. The reason why the iris authentication process can be performed by using the circular iris 190 image obtained by the correction process will be described. FIG. 5 is a diagram for explaining the reason why iris authentication processing can be performed by the iris authentication device 1 according to the first embodiment of the present invention. FIG. 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 has a planar shape, and the image of the elliptical iris 90 obtained by obliquely photographing does not have a portion lacking information on the iris eyelid pattern. By correcting the image to the shape of the iris 190, it is possible to obtain 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. Therefore, according to the iris authentication apparatus 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. Is possible.

  Strictly speaking, if the angle θ at which the subject 30 is photographed in FIG. 1 becomes too large, the authentication information created from the circular iris 190 obtained by photographing the subject 30 from the front, and the subject Since there is a possibility that authentication information created from an image obtained by correcting an elliptical iris 90 obtained by photographing 30 from an oblique direction into a circular shape may be different, keeping the person 30 to be authenticated within a predetermined range, It is desirable to create more accurate authentication information. The value of the angle θ can be obtained by empirically obtaining a reliable range of the angle θ from the authentication rate by photographing the eye 31 of the person 30 to be authenticated from different angles, performing an authentication process. When the range of the angle θ is determined, for example, as shown in FIG. 6, a line-of-sight direction detection unit 150 that detects the line-of-sight direction of the person 30 to be authenticated with infrared rays or the like is provided. When the angle formed by the direction with respect to the optical axis direction (Z direction) of the photographing unit 2 exceeds the above-described range of the angle θ, the photographing unit 2 does not photograph an eye image, and the capture processing unit 3 does not capture. Alternatively, the authenticating person 30 can be more surely authenticated by controlling the control unit 6 so that the authentication processing unit 17 does not perform the authentication process. FIG. 6 is a diagram illustrating another example of the iris authentication device 401 according to the first embodiment of the present invention. As the line-of-sight direction detection unit 150, known means such as a configuration using infrared rays can be used.

  Next, the operation of the iris authentication device 1 according to the first embodiment of the present invention will be described. FIG. 7 is a flowchart showing the operation steps of the iris authentication device 1 according to the first embodiment of the present invention.

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

  Note that the light source unit 7 does not necessarily have to be turned on when a clear eye image that can be sufficiently used for authentication can be taken even if the light source unit 7 does not emit light.

  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).

  In step S3, when the capture processing unit 3 can capture the image, the process proceeds to step S5. In step S3, when the image cannot be captured, the process returns to step S2, and the control unit 6 returns to step S2. The photographing unit 2 is caused to photograph the eye 31 of the person 30 to be authenticated (S4).

  In step S4, when the capture processing unit 3 performs image capture processing, the captured eye image is sent to the authentication processing unit 17, and the iris detection unit 11 of the authentication processing unit 17 extracts the eye image from the eye image. The elliptical iris 90 is detected, and an image of the elliptical iris 90 is sent to the circular correction unit 12 (S5).

  Then, the circular correction unit 12 approximates the image of the iris 90 to an ellipse, and after converting it to the standard shape as described above, the minor axis size is made to coincide with the major axis size so as to be circular. Then, a correction process for enlarging the image is performed, and an image of the circular iris 190 is sent to the authentication information creation unit 19 (S6).

  Next, authentication processing is performed in the authentication processing unit 17 (S7). Specifically, first, authentication information is created from the image of the iris 190 corrected to a circular shape in the authentication information creation unit 19 of the authentication processing unit 17, and is output to the collation unit 20. The collation unit 20 calculates the degree of mismatch between the authentication information created by the authentication information creation unit 19 and the registered authentication information stored in the storage unit 21, and the value is the authentication result determination unit 22. Sent to. Further, the authentication result determination unit 22 performs comparison with a predetermined threshold, determines whether or not the person 30 to be authenticated is a person registered in advance, and sends the result to the output unit 23.

  Thus, according to the iris authentication device 1 in the first exemplary embodiment of the present invention, by performing the iris authentication process using the eye image obtained by photographing the eye 31 of the person 30 to be authenticated from an oblique direction, It is possible to determine whether or not the person 30 to be authenticated is a person registered in advance.

  As described above, when the iris authentication apparatus 1 according to the embodiment of the present invention is used, an elliptical shape photographed from an oblique direction even in a situation where the photographing unit 2 and the eye 31 of the authenticator 30 do not face each other. Since the iris authentication process can be performed using the image of the iris 90, there is no need to guide the person to be authenticated 30 to view the photographing unit 2, and the person to be authenticated 30 is unconsciously subjected to the authentication process. It is possible to provide an iris authentication device and an iris authentication method capable of performing the above.

  In the first embodiment of the present invention, each function block of the capture processing unit 3 and the authentication processing unit 17 may be realized by software or hardware such as a dedicated circuit. It may be realized with. 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 iris authentication apparatus and the iris authentication 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.

(Second Embodiment)
Next, the iris authentication apparatus 101 in the 2nd Embodiment of this invention is demonstrated. FIG. 8 is a block diagram showing the configuration of the iris authentication apparatus 101 according to the second embodiment of the present invention. Also in the iris authentication apparatus 101 in the second embodiment of the present invention, as shown in FIG. 1, the eye 31 of the person 30 to be authenticated is photographed from an oblique direction, and the iris authentication process is performed using the eye image. What can be done is the same as the iris authentication apparatus 1 in the first embodiment.

  As shown in FIG. 8, the configuration of the iris authentication device 101 in the second embodiment of the present invention is different from the configuration of the iris authentication device 1 in the first embodiment. A place where the circular correction unit 12 is not provided and an authentication information creation unit 25 which directly creates authentication information from an image of the elliptical iris 90 is provided instead of the authentication information creation unit 19.

  The other components are common to the components of the iris authentication apparatus 1 shown in the first embodiment, and thus the common components are denoted by the same reference numerals and description thereof is omitted.

  The elliptical authentication information creation unit 25 of the iris authentication apparatus 101 according to the second embodiment of the present invention directly performs polar coordinate conversion on the image of the elliptical iris 90 detected by the iris detection unit 11. Authentication information is generated. As a code generation method after polar coordinate conversion in the elliptical authentication information creating unit 25, 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 the function of the elliptical authentication information creation unit 25 of the iris authentication apparatus 101 according to the second embodiment of the present invention. FIG. FIG. 9B corresponds to the line segments 110 to 125 of the circular iris 190 shown in FIG. 9A with respect to the elliptical iris 90. It is the figure which showed the line segments 110-125 to do.

  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. Is divided by a predetermined angle, line segments 110 to 125 connecting the outline of the pupil 191 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 iris authentication device 101 according to the second 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. As shown, it has an elliptical shape. The elliptical authentication information creating unit 25 of the iris authentication apparatus 101 according to the second embodiment of the present invention has an elliptical shape as shown in FIG. Using the line segments 110 to 125 corrected according to the flatness ratio H and the rotation angle θR of the iris 90, 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 91, the contour of the iris 90, and the line segments 110 to 125 when the region is divided are the flatness 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.

  In the iris authentication apparatus 101 according to the second embodiment of the present invention, strictly speaking, if the angle θ at which the subject 30 is photographed in FIG. There is a possibility that the authentication information created from the photographed circular iris 190 and the authentication information created from the elliptical iris 90 photographed from the oblique direction of the person 30 to be authenticated are different. In order to create more accurate authentication information, it is desirable to keep it within a predetermined range, as in the iris authentication apparatus 1 in the first embodiment. Therefore, the gaze direction detection unit 150 as shown in FIG. 6 is mounted on the iris authentication device 101 in the second embodiment, and the gaze direction of the person 30 to be authenticated is the optical axis direction (Z direction) of the imaging unit 2. ) Is beyond the range of the predetermined angle θ, the photographing unit 2 is not photographed, the capture processing unit 3 is not captured, or the authentication processing unit 127 is not authenticated. In addition, by making the control unit 6 perform control, it is possible to more reliably authenticate the person 30 to be authenticated.

  As described above, according to the iris authentication apparatus 101 in the second embodiment of the present invention, the elliptical authentication information creating unit 25 directly applies to the circular iris 190 with respect to the elliptical iris 90. Since polar coordinate conversion equivalent to that performed can be performed, the authentication information creation unit 25 can create authentication information by the same encoding process as that performed for the circular iris 190.

  Therefore, according to the iris authentication apparatus 101 of the second embodiment of the present invention, the collation unit 20 is registered in advance with the authentication information created by the elliptical authentication information creation unit 25 and the storage unit 21. The degree of inconsistency can be calculated by comparing and collating with the registered authentication information of the person who has been registered. Here, the registration authentication information stored in the storage unit 21 may be registration authentication information created from a circular iris 190 obtained by photographing the person to be authenticated 30 from the front. It goes without saying that registration authentication information created from an elliptical iris 90 obtained by photographing the person 30 from an oblique direction may be used. Practically, a more reliable authentication result can be obtained by using registered authentication information created from a circular iris 190 obtained by photographing the person to be authenticated 30 from the front.

  Here, the operation of the iris authentication apparatus 101 according to the second embodiment of the present invention will be described. FIG. 10 is a flowchart showing the operation steps of the iris authentication apparatus 101 in the second embodiment of the present invention.

  In FIG. 10, the operation of the iris authentication apparatus 101 in the second embodiment of the present invention is the same as the operation of the iris authentication apparatus 1 in the first embodiment shown in FIG. Reference numerals are assigned and explanations thereof are omitted. As shown in FIG. 10, the difference between the operation steps of the iris authentication apparatus 101 in the second embodiment of the present invention and the operation steps of the iris authentication apparatus 1 in the first embodiment is shown in step S6. Further, instead of the circular correction step of the elliptical iris 90 by the circular correction unit 12, a polar coordinate conversion step for the image of the elliptical iris 90 by the elliptical authentication information creation unit 25 is provided (S16).

  Following step S16, an authentication process step (S17) is performed. Specifically, first, in the elliptical authentication information creation unit 25 of the authentication processing unit 127, authentication information is created from the polar coordinate-converted data of the image of the elliptical iris 90, and is output to the matching unit 20. Further, the collation unit 20 calculates the degree of inconsistency between the authentication information created by the elliptical authentication information creation unit 25 and the registered authentication information stored in the storage unit 21, and the value is determined as an authentication result determination. Sent to the unit 22. Further, the authentication result determination unit 22 performs comparison with a predetermined threshold, determines whether or not the person 30 to be authenticated is a person registered in advance, and sends the result to the output unit 23.

  As described above, the iris authentication apparatus 101 according to the second embodiment of the present invention also performs the iris authentication process using the eye image obtained by photographing the eye 31 of the person 30 to be authenticated from an oblique direction. It is possible to determine whether or not the authenticator 30 is a person registered in advance.

  As described above, when the iris authentication apparatus 101 according to the second embodiment of the present invention is used, even if the photographing unit 2 and the eye 31 of the authenticator 30 are not facing each other, the image is taken from an oblique direction. Since the iris authentication process can be performed using the image of the elliptical iris 90, the subject 30 need not be guided to look at the photographing unit 2 and the subject 30 is authenticated unconsciously. It is possible to provide an iris authentication device and an iris authentication method that can be processed.

  In the second embodiment of the present invention as well, each function block of the capture processing unit 3 and the authentication processing unit 127 may be realized by software or hardware such as a dedicated circuit. It may be realized with. 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 iris authentication apparatus and the iris authentication 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.

(Third embodiment)
Next, the iris authentication apparatus 201 in the 3rd Embodiment of this invention is demonstrated. FIG. 11 is a block diagram showing a configuration of an iris authentication apparatus 201 according to the third embodiment of the present invention. As shown in FIG. 11, the configuration of the iris authentication apparatus 201 in the third embodiment of the present invention is the same as the configuration of the iris authentication apparatus 1 in the first embodiment of the present invention and the second configuration of the present invention. The difference from the configuration of the iris authentication apparatus 101 in the embodiment is that a capture process is performed by switching a plurality of imaging units 2 and 102 and outputs from the plurality of imaging units 2 and 102 under the control of the control unit 106. The switching unit 103 that outputs to the unit 3 is provided. As the authentication processing units 17 and 127, either the authentication processing unit 17 in the first embodiment or the authentication processing unit 127 in the second embodiment can be used.

  In the iris authentication apparatus 201 according to the third embodiment of the present invention, it is desirable to use cameras having different resolutions and imaging magnifications as the plurality of imaging units 2 and 102. This is because, by using the imaging units 2 and 102 having different resolutions and imaging magnifications, the eye 31 suitable for performing the authentication process at any distance from the iris authentication device 201 of the person 30 to be authenticated. This is because a configuration capable of capturing an image can be realized. Further, by making the shooting directions of the plurality of shooting units 2 and 102 different, it is possible to take the eye image of the person 30 to be authenticated in a wider range.

  As described above, the iris authentication apparatus 201 according to the third embodiment of the present invention is compared with the iris authentication apparatus 1 according to the first embodiment and the iris authentication apparatus 101 according to the second embodiment. Thus, authentication processing can be performed without making the person to be authenticated 30 further aware of the existence of the iris authentication device 201.

  In the third embodiment of the present invention, an example in which a plurality of imaging units 2 and 102 are mounted for one iris authentication apparatus 201 is shown, but the present invention is not limited to this example. Absent. For example, constructing an iris authentication system including a plurality of iris authentication apparatuses 1 according to the first embodiment or iris authentication apparatuses 101 according to the second embodiment, each having a different magnification and resolution of the photographing unit 2. However, as in the above-described example, a configuration capable of capturing an eye image and performing authentication processing using the eye image in a wide range without making the person to be authenticated 30 further aware of the existence of the iris authentication device is realized. be able to.

  As described above, if the iris authentication device and the iris authentication method according to the present invention are used, it is not necessary to photograph the eye of the person to be authenticated from the front, and the user's line of sight is directed toward the camera. Or having the camera pointed toward the person to be authenticated, and so that there is no need to make various measures. Personal authentication using at least the iris image of the person to be authenticated It is useful as an iris authentication device and an iris authentication method for performing the above.

The figure which shows the usage type of the iris authentication apparatus in the 1st Embodiment of this invention. Functional block diagram showing the configuration of the iris authentication apparatus in the first embodiment of the present invention The figure for demonstrating the process of the iris detection part of the iris authentication apparatus in the 1st Embodiment of this invention. The figure for demonstrating the function of the circular correction | amendment part of the iris authentication apparatus in the 1st Embodiment of this invention. The figure for demonstrating the reason an iris authentication process is possible by the iris authentication apparatus in the 1st Embodiment of this invention. The figure which shows another example of the iris authentication apparatus in the 1st Embodiment of this invention. The flowchart which shows the operation | movement step of the iris authentication apparatus in the 1st Embodiment of this invention. The block diagram which shows the structure of the iris authentication apparatus in the 2nd Embodiment of this invention. The figure for demonstrating the function of the elliptical authentication information preparation part of the iris authentication apparatus in the 2nd Embodiment of this invention. The flowchart which shows the operation | movement step of the iris authentication apparatus in the 2nd Embodiment of this invention. The block diagram which shows the structure of the iris authentication apparatus in the 3rd Embodiment of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1,101,201,401 Iris authentication apparatus 2,102 Image pick-up part 3 Capture processing part 6,106 Control part 7 Light source part 9 Image quality determination part 10 Eye detection part 11 Iris detection part 12 Circular correction part 17,127 Authentication processing part 19 Authentication information creation unit 20 Collation unit 21 Storage unit 22 Authentication result determination unit 23 Output unit 25 Elliptical authentication information creation unit 30 Person to be authenticated 31 Eye 70 Eyeball 71, 90, 190 Iris 72, 91, 191 Pupil 92 White eye 100 Partial image 103 switching part 110-125 line segment 150 gaze direction detection part

Claims (15)

A photographing unit for photographing the eye of the person to be authenticated from an oblique direction;
An iris authentication apparatus, comprising: an authentication processing unit that performs authentication processing of the person to be authenticated using an image of a part including at least an iris of an image photographed by the photographing unit. The iris authentication apparatus according to claim 1, further comprising an iris detection unit that detects an elliptical iris image from an image photographed by the photographing unit. A circular correction unit that corrects the elliptical iris image detected by the iris detection unit into a circular shape;
The iris authentication apparatus according to claim 2, wherein the authentication processing unit performs authentication processing of the person to be authenticated using an iris image corrected to a circular shape by the circular correction unit. The authentication processing unit
An authentication information creating unit for creating authentication information from the iris image corrected to the circular shape;
The iris authentication apparatus according to claim 3, further comprising: a collation unit that compares and collates authentication information created by the authentication information creation unit with registration authentication information of a person registered in advance. The authentication processing unit
An elliptical authentication information creating unit for creating authentication information from the elliptical iris image detected by the iris detecting unit;
The iris authentication apparatus according to claim 2, further comprising: a verification unit that compares and collates authentication information created by the elliptical authentication information creation unit with registration authentication information of a person registered in advance. The iris authentication apparatus according to any one of claims 1 to 5, further comprising an image quality determination unit that determines an image quality of an image captured by the imaging unit. The iris authentication device according to any one of claims 1 to 6, further comprising an eye detection unit that determines whether or not an eye is captured in an image captured by the imaging unit. . The iris authentication apparatus according to claim 7, wherein the eye detection unit determines whether an oval eye is captured in an image captured by the imaging unit. The iris authentication apparatus according to claim 1, further comprising a light source unit that irradiates a region including at least eyes of the person to be authenticated. The iris authentication device according to claim 1, wherein the photographing unit includes a plurality of photographing devices that photograph the eyes of the certifier from an oblique direction. The iris authentication apparatus according to claim 10, wherein the plurality of imaging devices are imaging devices having different resolutions. The iris authentication apparatus according to claim 10, wherein the plurality of imaging devices are imaging devices having different imaging magnifications. A line-of-sight detection unit that detects the direction of the line of sight of the person to be authenticated;
A control unit that stops the processing of the imaging unit or the authentication processing unit when an angle formed by the direction of the gaze detected by the gaze direction detection unit and the imaging direction of the imaging unit exceeds a predetermined angle; The iris authentication apparatus according to any one of claims 1 to 12, further comprising: an iris authentication apparatus according to any one of claims 1 to 12. A first step of photographing the eye of the person to be authenticated from an oblique direction;
An iris authentication method, comprising: a second step of performing authentication processing of the person to be authenticated using an image of a part including at least an iris of the image photographed in the first step. On the computer,
A first step in which an image taken from an oblique direction of the eye of the person to be authenticated is input;
An iris authentication program that executes a second step of performing authentication processing of the person to be authenticated using an image of a part including at least an iris of the image input in the first step.

Images