JP2007236668A - Photographic device, authentication device and photographic method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a photographic device capable of guiding a subject in a distance direction from the device and either of upper/lower/right/left directions. <P>SOLUTION: This photographic device is provided with a photographing part 4 photographing at least an eye of the subject 30, a distance measuring part 2 repeatedly measuring the distance to the subject 30, a determination part 52 determining whether the subject 30 is within a focused range of the photographing part 4 based on the distance to the subject 30 measured by the distance measuring part 2, a guide image creation part 53 creating a guide image of the subject, and a display part 50 displaying the image of the subject 30 when the determination part 52 determines that the subject 30 is positioned within the focused range, and displaying the guide image created by the guide image creation part 53 when the determination part 52 determines that the subject 30 is not present in the focused range. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an authentication device that performs personal authentication using an image of a subject's eye, and more particularly to an imaging device that guides and captures the subject's eye to an appropriate position, an authentication device using the same, and an imaging method. .

  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. The degree of inconsistency with the registered information (hereinafter referred to as registration authentication information) is calculated, and if it is determined that they match each other by comparing the degree of inconsistency with a predetermined threshold, the person to be authenticated registers in advance. It is a method of authenticating that the person has been approved.

  In the iris authentication method, in order to perform image processing for creating authentication information, it is necessary to capture a clear image of the eye (particularly the iris) of a high-resolution subject. Relatively narrow-angle (telephoto) lenses have been used. On the other hand, in order to reduce the cost of the apparatus, a fixed focus lens system may be used as the optical system. When such a fixed-focus lens system is used as an optical system, it is necessary to realize a guidance method for easily and quickly placing the eye within the focusing range of the lens system with respect to the subject. It was.

Various techniques have been proposed for guiding the eye position of the subject within the focusing range of the lens system. For example, while measuring the distance to the subject and using a plurality of LEDs, the subject is guided within the in-focus range by changing the number of LEDs to be lit as the distance changes. The technique which can do is proposed (for example, refer patent document 2).
Japanese Patent No. 3307936 JP 2002-342750 A

  However, in the above-described technique, the subject can be guided in the distance direction (front-rear direction toward the apparatus, hereinafter also referred to as Z direction), but up, down, left-right direction (hereinafter, XY) toward the apparatus. In order to guide the subject with respect to the direction), another configuration or method has to be used.

  The present invention has been made in view of such a problem, and provides an imaging device, an authentication device, and an imaging method capable of guiding a subject in any of the distance direction from the device and the vertical and horizontal directions. With the goal.

  In order to solve such a problem, the imaging apparatus of the present invention includes an imaging unit that captures at least an eye of a subject, a distance measuring unit that repeatedly measures the distance to the subject, and the subject measured by the distance measuring unit. A determination unit that determines whether or not the subject is in the focus range of the photographing unit, a guide image creation unit that generates a guide image of the subject, and a determination unit based on the distance of the subject, the subject is in the focus range A display unit that displays an image of a subject when the determination unit determines that the subject is not in the focusing range, and displays a guide image created by the guide image creation unit. It is characterized by that.

  According to such a configuration, the determination unit determines whether or not the subject is in the in-focus range, and based on the result, the display unit is different depending on whether or not the subject is in the in-focus range. Since the display is performed, it is possible to provide an imaging apparatus that can guide the subject in either the distance direction from the apparatus or in the vertical and horizontal directions.

  The determination unit further determines whether the subject is closer or farther than the in-focus range of the photographing unit, and the guide image creation unit is an enlarged and blurred enlargement guide of the subject's eyes The image may be created, and the display unit may be configured to display an enlarged guide image when the determination unit determines that the subject is closer to the in-focus range.

  According to such a configuration, when the subject is closer to the in-focus range, an enlarged enlarged guide image is displayed, so that the subject is intuitively too close to the apparatus. It is possible to realize a configuration in which it is easy to notice that it is in a position.

  The determination unit further determines whether the subject is closer or farther than the in-focus range of the photographing unit, and the guidance image creation unit reduces the blurred and blurred guidance of the subject's eyes. An image may be created, and the display unit may be configured to display a reduced guidance image when the determination unit determines that the subject is far from the focusing range.

  According to such a configuration, when the subject is further away from the in-focus range, a reduced reduced guidance image is displayed, so that the subject is intuitively too far from the apparatus. It is possible to realize a configuration in which it is easy to notice that it is in a position.

  Further, the enlarged guide image may be a black and white image and the subject image may be a color image.

  According to such a configuration, the guide image when the subject is in the focus range is displayed in color, while the enlarged guide image is displayed in black and white, so that the subject is in the focus range. It is possible to realize a configuration in which it can be more intuitively noticed whether or not.

  Furthermore, the reduction induction image may be a black and white image, and the subject image may be a color image.

  According to such a configuration, the guide image when the subject is in the focus range is displayed in color, while the reduced guide image is displayed in black and white, so that the subject is in the focus range. It is possible to realize a configuration in which it can be more intuitively noticed whether or not.

  Further, the guide image creating unit may be configured to determine the enlargement ratio of the enlarged guide image based on the distance to the subject measured by the distance measuring unit.

  According to such a configuration, the enlargement ratio of the enlargement guide image is further determined based on the distance from the subject to the device, so that the subject is intuitively positioned at a position that is out of focus range. It is possible to realize a configuration that can know whether or not

  Further, the guide image creating unit may be configured to increase the enlargement ratio of the enlarged guide image as the distance to the subject is shorter.

  According to such a configuration, the closer the distance to the subject is, the larger the enlargement ratio is. Therefore, it is possible to more intuitively know how far the subject is out of focus range. it can.

  Further, the guide image creating unit may be configured to determine a reduction rate of the reduced guide image based on the distance to the subject measured by the distance measuring unit.

  According to such a configuration, the reduction ratio of the reduced guidance image is further determined based on the distance from the subject to the apparatus, so that the subject is intuitively positioned at a position that is out of focus range. It is possible to realize a configuration that can know whether or not

  Further, the guide image creating unit may be configured to increase the reduction ratio of the reduced guide image as the distance to the subject increases.

  According to such a configuration, since the reduction ratio increases as the distance to the subject increases, it is possible to more intuitively know how far the subject is out of focus range. it can.

  Next, the authentication device of the present invention is based on the imaging device of the present invention, an eye image evaluation unit that evaluates an eye image of a subject imaged by the imaging unit of the imaging device, and a result evaluated by the eye image evaluation unit. And an authentication processing unit that performs an authentication process on the eye image.

  According to such a configuration, the determination unit of the photographing apparatus further determines whether or not the subject is in the in-focus range, and based on the result, the display unit determines when the subject is in the in-focus range. Since the display is different depending on whether the subject is not, an authentication device equipped with an imaging device capable of guiding the subject in either the distance direction from the device or in the vertical and horizontal directions can be provided.

  The authentication processing unit includes an authentication information creating unit that creates authentication information from a part including at least an iris of an image photographed by the photographing unit, a storage unit that stores registration authentication information of a person registered in advance, and authentication information By comparing the mismatch information calculated in the mismatch degree calculation unit with a predetermined threshold by calculating a mismatch degree between the authentication information created in the creation unit and the registration authentication information stored in the storage unit It may be configured to include an authentication result determination unit that determines whether or not the subject can be authenticated as a person registered in advance.

  According to such a configuration, an authentication device using an iris authentication method with a high authentication rate can be realized.

  The eye image evaluation unit includes an image quality determination unit that determines the image quality of the eye image of the subject captured by the imaging unit, and an eye detection unit that determines whether or not the eye is captured in the eye image. The processing unit may be configured to perform authentication processing using an eye image that has been determined by the image quality determination unit to have good image quality and that has been determined by the eye detection unit to have taken an eye.

  According to such a configuration, the authentication process is further performed by the image that is determined that the image quality is good and the eye is photographed in the eye image evaluation unit, so that the authentication rate can be further increased.

  Next, the photographing method of the present invention includes a first step of photographing at least an eye of a subject with a photographing unit, a second step of repeatedly measuring the distance to the subject, and the subject measured in the second step. In the third step for determining whether or not the subject is within the focusing range of the photographing unit, the fourth step for creating a guide image of the subject, and the third step, the subject is in focus. The image of the subject is displayed when it is determined that the subject is in the focus range, and the guide image created in the fourth step is displayed when the determination unit determines that the subject is not in the focus range. And 5 steps.

  According to such a method, in the third step, it is determined whether or not the subject is in the in-focus range, and based on the result, in the fifth step, when the subject is in the in-focus range and so on. Since a different display is performed depending on whether the subject is not, it is possible to provide a photographing method capable of guiding the subject in any of the distance direction from the apparatus and the vertical and horizontal directions.

  As described above, according to the present invention, it is possible to provide an imaging device, an authentication device, and an imaging method capable of guiding a subject in any of the distance direction from the device and the vertical and horizontal directions.

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

(Embodiment)
First, the authentication device 1 and the imaging device 60 in the embodiment of the present invention will be described. FIG. 1 is a front view of an authentication device 1 according to an embodiment of the present invention as seen from the front.

  As shown in FIG. 1, the authentication device 1 includes a photographing device 60.

  The photographing apparatus 60 according to the embodiment of the present invention has a photographing unit 4 for photographing the eye of a subject 30 (not shown in FIG. 1; see FIG. 2), and various displays described later for guiding the subject 30. From the measurement results of the display unit 50, the light source unit 7 that irradiates the eye of the subject 30, the distance measurement unit 2 that repeatedly measures the distance to the subject 30, and the distance measurement unit 2, the subject 30 is within the focusing range of the photographing unit 4. A determination unit 52 that determines whether or not there is, a guide image creation unit 53 that generates a guide image to be displayed on the display unit 50 based on the determination result of the determination unit 52, and the photographing unit 4, the light source unit 7, A control unit 31 that controls the determination unit 52 and the guide image creation unit 53 is provided.

  The light source unit 7 irradiates the eye with light having a wavelength in the near infrared region (a wavelength of about 700 nm to about 1000 nm) in order to capture a clear iris image with good eye contrast of the subject 30. A light source such as an LED array can be used.

  As an example of the photographing unit 4, a monochrome camera or a color camera using a CCD or CMOS as an image sensor can be used. As a lens system to be mounted on the photographing unit 4, it is desirable to mount a telephoto lens capable of enlarging and photographing the eye area of the subject 30. Further, the photographing unit 4 is equipped with a fixed focus type lens system, and the photographing device 60 or the authentication device 1 needs to guide the subject 30 within a focused range (hereinafter also referred to as a focused range). is there. This guidance method will be described later.

  As the distance measuring unit 2, a known distance measuring unit capable of repeatedly measuring the distance to the subject 30 such as a distance measuring sensor using infrared rays can be used.

  Based on the output from the distance measurement unit 2, the determination unit 52 determines whether or not the subject 30 is within the focusing range of the photographing unit 4, and further whether the subject 30 is positioned closer to the focusing range. It is determined whether it is located at. Specifically, for example, the value of the width of the focusing range of the photographing unit 4 is stored in advance in the determination unit 52 as a threshold range, and the determination unit 52 calculates the distance calculated from the output from the distance measurement unit 2. When the value is larger than the maximum value of the above-described threshold range, it is determined that the subject 30 is far from the in-focus range, and the distance value calculated from the output from the distance measuring unit 2 is the threshold value range. When it is smaller than the minimum value, it is determined that the subject 30 is closer to the focus range. Furthermore, when the distance value calculated from the output from the distance measurement unit 2 is within the above-described threshold range, the determination unit 52 can determine that the subject 30 is within the in-focus range.

  As the display unit 50, various known display devices capable of displaying a two-dimensional image such as an LCD can be used.

  The guide image creation unit 53 creates various guide displays to be displayed on the display unit 50 based on the determination result of the determination unit 52.

  Note that the functions of the guide image creation unit 53 and the determination unit 52 in the present embodiment may be realized by hardware by providing a dedicated circuit or the like, and each function is described by software and executed by a computer. May be.

  Here, the display that can be performed on the subject 30 by the imaging device 60 or the authentication device 1 according to the embodiment of the present invention will be described. 2 is a diagram for explaining the positional relationship between the imaging device 60 or the authentication device 1 and the subject 30 in the embodiment of the present invention, and FIG. 3 is the imaging device 60 or the authentication in the embodiment of the present invention. FIG. 6 is a diagram for explaining display on the subject 30 of the device 1.

  Here, as shown in FIG. 2, the focusing range of the imaging unit 4 of the imaging device 60 is a range A, a region closer to the focusing range is a range C, and a region farther than the focusing range is a range B. And

  The determination unit 52 determines whether the subject 30 exists in the above-described range A, range B, or range C based on the output value from the distance measurement unit 2. The guide image creation unit 53 creates a guide image to be used for guiding the subject 30 based on the determination result of the determination unit 52.

  Specifically, when the determination unit 52 determines that the subject 30 exists within the range A in FIG. 2, that is, the in-focus range of the imaging unit 4, the guide image creation unit 53 displays the image captured by the imaging unit 4. The guide image 71 displaying the eyes of the subject 30 as shown in FIG. Usually, when the subject 30 is within the focusing range of the photographing unit 4, a focused image is photographed, and this image can be used as it is. If the eye position in the guide image 71 is the same as the guide image that moves the subject 30 in the vertical and horizontal directions by moving the subject 30 in the vertical and horizontal directions with respect to the photographing device 60, the subject 30. On the other hand, guidance in the up / down / left / right direction (XY direction) with respect to the imaging device 60 can be performed. Specifically, the subject 30 has only to move so that its own eye position is displayed in the central portion of the display unit 50.

  Further, when the determination unit 52 determines that the subject 30 exists farther than the range B in FIG. 2, that is, the in-focus range of the imaging unit 4, the guide image creation unit 53 displays the image captured by the imaging unit 4. 3B is used to create a reduced guide image 72 after blurring the eyes of the subject 30 from the above-described guide image 71 as shown in FIG. Thus, when the subject 30 is located farther than the in-focus range, the blurred and reduced guide image 72 is displayed on the display unit 50, so that the subject 30 is within the in-focus range. It is easy to realize that there is no such thing and that it is necessary to approach the photographing device 60. In the range B, the image photographed by the photographing unit 4 is not necessarily an image that is visually blurred. Therefore, in order to guide the subject 30 more intuitively, an eye photographed by the photographing unit 4 is used. The image is blurred by a known method such as various image processing methods, and is reduced to a certain degree to be a guided image 72.

  On the other hand, when the determination unit 52 determines that the subject 30 is present in the vicinity of the range C in FIG. 2, that is, the in-focus range of the imaging unit 4, the guide image creation unit 53 displays the image captured by the imaging unit 4. 3C, an enlarged guide image 73 is created after blurring the eyes of the subject 30 with respect to the guide image 71 described above. Thus, when the subject 30 is located closer to the focus range, the blurred and enlarged guide image 73 is displayed on the display unit 50, so that the subject 30 is within the focus range. It is easy to realize that there is nothing and that it is necessary to keep away from the photographing device 60. In the range C, the image captured by the image capturing unit 4 is not necessarily an image that is visually blurred. Therefore, in order to guide the subject 30 more intuitively, the image captured by the image capturing unit 4 is used. The image is blurred by a known method such as various image processing methods, and is forcedly enlarged to some extent to be a guide image 73.

  Further, the guide image creation unit 53 sets the image enlargement rate when creating the guide image 73 and the image reduction rate when creating the guide image 72 according to the distance from the imaging device 60 to the subject 30. It may be changed. FIG. 4 is a diagram illustrating a relationship between the enlargement ratio and the reduction ratio and the distance from the imaging apparatus 60 to the subject 30 in the imaging apparatus 60 or the guidance image creation unit 53 of the authentication apparatus 1 according to the embodiment of the present invention. . As shown in FIG. 4, the horizontal axis indicates the distance from the imaging device 60 to the subject 30, and the vertical axis indicates the enlargement ratio or reduction ratio when creating a guide image at that distance.

  In FIG. 4, the enlargement ratio (reduction ratio) of the image when the subject 30 is in the in-focus range (range A) is shown as “1” for simplicity. As shown in FIG. 4, in the range B, the further away the subject 30 is from the imaging device 60, the larger the reduction ratio when creating the guide image 73. Conversely, in the range C, the subject 30 is in the imaging device. The closer to 60, the greater the enlargement factor when creating the guide image 72. However, the value of the enlargement ratio in the range A and the value of the enlargement ratio in the range B, and the value of the reduction ratio in the range A and the value of the reduction ratio in the range C are discontinuous. In this way, the subject 30 can know more intuitively that he has entered the in-focus range of the photographing unit 4.

  Further, when a color camera is used as the photographing unit 4, the guide image creating unit 53 sets the guide image 71 when the subject 30 is in the range A as a color image, while the subject 30 is in the range B or C. By making the guide images 72 and 73 in the case of a black and white image, the subject 30 can more intuitively know that the subject 30 has entered the in-focus range of the photographing unit 4.

  Here, the configuration of the authentication device 1 including the imaging device 60 according to the embodiment of the present invention will be described. FIG. 5 is a block diagram for explaining the configuration of the authentication device 1 according to the embodiment of the present invention.

  As illustrated in FIG. 5, the authentication device 1 includes the above-described imaging device 60, performs image quality determination of the eye image captured by the imaging unit 4, and the image determined to be good to the authentication processing unit 17. An eye image evaluation unit 3 that performs a sending process (hereinafter, this process is referred to as a capture process), and an authentication process that performs an iris authentication process by a predetermined method as will be described later using an image captured by the eye image evaluation unit 3 The output part 23 which outputs the authentication result in the part 17 and the authentication process part 17 is provided, and the control part 31 controls each operation | movement of the eye image evaluation part 3 and the authentication process part 17.

  As the output unit 23, for example, a known display device using liquid crystal, EL, or the like can be used, a device such as a speaker that can notify the subject 30 of the authentication result or the like by voice, or connected to the outside. It is possible to use various types of communication devices and the like that can transmit information such as authentication results to the devices. It is also possible to share the output unit 23 with the display unit 50.

  The eye image evaluation unit 3 shoots a circular object that is regarded as an eye in the image output from the image capturing unit 4 and the image quality determination unit 9 that determines the image quality of the image from the image output from the image capturing unit 4. The eye detection unit 10 that determines whether or not the eye is being used.

  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 integrating and determining that the larger the integrated value is, the better the image quality can be used, but the present invention is not limited to this method. For example, using the average luminance information of the entire image, a method for determining that the image quality is good when the average luminance information is within a predetermined threshold range, another known image quality evaluation method, or a combination of these methods Can be used.

  The eye detection unit 10 determines whether or not a circular object such as an iris or a pupil is photographed from the eye image. As a determination method in the eye detection unit 10, for example, in an eye image photographed by the photographing unit 4, a round area estimated to be a pupil or a black eye part (for example, a round area having a lower luminance than the surrounding area). ) Is detected by performing pattern matching processing between the eye image and an image having a low-luminance area of a predetermined size, or the position of a pupil candidate is detected from the eye image. A pupil candidate detection unit, and a luminance difference calculation unit for obtaining a difference between the maximum value and the minimum value of the luminance of the eye image on the circumference of a circle having a predetermined radius with the center coordinate of the pupil candidate as a center. A method of determining that the pupil candidate is a pupil when the output of the calculation unit is within a predetermined threshold can be used.

  The authentication processing unit 17 uses a predetermined method from the iris detection unit 11 that detects the iris part of the eye from the image output from the eye image evaluation unit 3 and the iris part image detected by the iris detection unit 11. An authentication information creating unit 19 for creating authentication information, a storage unit 21 for storing registration authentication information for both eyes of a person registered in advance, and a registration authentication information and authentication information creating unit 19 stored in the storage unit 21. A mismatch degree calculation unit 20 that calculates a mismatch degree by comparing with the created authentication information, and a value of the mismatch degree calculated by the mismatch degree calculation unit 20 (hereinafter, this value is also referred to as an HD value or a Hamming value) And an authentication result determination unit 22 that determines whether or not the subject 30 is a person who has been registered in advance.

  Here, processing of the iris detection unit 11 will be described. First, the iris detection unit 11 determines the boundary between the iris of the eye image and the white eye portion as the iris contour. The determination of the iris contour is performed, for example, by making use of the fact that the iris is circular, changing the radius while moving the center coordinates, performing circular integration of the luminance value, and determining the position where the value changes most greatly. This can be done by a method for determining the iris contour. According to this method, the center coordinates and radius when the iris contour of the iris is an arc are calculated.

  Further, the iris detection unit 11 determines the boundary between the iris and the eyelid in the eye image as the eyelid contour. The shape of the eyelid contour is determined by matching the shape of the part where the brightness difference between the iris and the eyelid is large with the spline curve having various shapes, so that the shape of the best fit spline curve is determined. The shape is determined. The iris image cut out by the iris detection unit 11 in this way is sent to the authentication information creation unit 19. The authentication information creating unit 19 creates authentication information from the iris image by a predetermined method.

  The storage unit 21 stores the registration authentication information of both eyes or one eye of a person registered in advance, and the mismatch degree calculation unit 20 includes the authentication information created by the authentication information creation unit 19 and the storage unit 21. The hamming value is calculated as information indicating the degree of inconsistency using the registered authentication information stored in the information and sent to the authentication result determination unit 22.

  The authentication result determination unit 22 determines whether or not the subject 30 is a person registered in advance using the mismatch level value (HD value) calculated by the mismatch level calculation unit 20 and a predetermined threshold value HDth. The authentication result determination unit 22 outputs information indicating the authentication result, that is, information indicating “authentication OK” to the output unit 23 when the subject 30 is registered in advance, and the subject 30 is registered in advance. If not, information indicating “authentication NG” is output to the output unit 23.

  Among the components of the authentication processing unit 17, an iris detection method in the iris detection unit 11, an authentication information creation method in the authentication information creation unit 19, a mismatch degree calculation method in the mismatch degree calculation unit 20, and As the authentication result determination method using the mismatch degree calculated by the mismatch degree calculation unit 20 in the authentication result determination unit 22, for example, the method described in Patent Document 1 can be used.

  As shown in FIG. 5, among the components of the authentication device 1, the display unit 50, the guide image creation unit 53, the distance measurement unit 2, the determination unit 52, the control unit 31, the light source unit 7, and the imaging unit 4 are included. By providing, the imaging device 60 that captures an eye image of the subject 30 can be configured.

  Next, operation | movement of the authentication apparatus 1 in embodiment of this invention is demonstrated. FIG. 6 is a diagram for explaining the operation of the authentication device 1 according to the embodiment of the present invention.

  As shown in FIG. 6, first, in the authentication device 1, the control unit 31 causes the distance measurement unit 2 to start measuring the distance from the authentication device 1 to the subject 30 (S1). Specifically, the control unit 31 causes the determination unit 52 to start determining the distance to the subject 30 from the output from the distance measurement unit 2. Thereafter, the distance measurement unit 2 repeatedly measures the distance to the subject 30 and outputs the measurement result to the determination unit 52.

  Next, the determination unit 52 determines whether the subject 30 is within the measurable range of the distance measurement unit 2 based on the output from the distance measurement unit 2. The determination result of the determination unit 52 is sent to the control unit 31 (S2).

  If it is determined in step S2 that the subject 30 is within the measurable range of the distance measuring unit 2, the process proceeds to step S3, where it is determined that the subject 30 is not within the measurable range of the distance measuring unit 2. If it is determined, the determination unit 52 repeatedly determines from the output from the distance measurement unit 2 whether or not the subject 30 has entered the measurable range.

  Subsequently, when it is determined in step S2 that the subject 30 has entered the measurable range of the distance measuring unit 2, the control unit 31 causes the light source unit 7 to start irradiating the eye of the subject 30 (S3). .

  Subsequently, the control unit 31 causes the determination unit 52 to determine whether or not the subject 30 is located within the focusing range of the optical system of the photographing unit 4 based on the output of the distance measurement unit 2 (S4).

  In step S4, when it is determined that the subject 30 exists farther (range B) than the in-focus range of the photographing unit 4 (usually, the subject 30 often moves toward the authentication device 1, and thus photographing). The control unit 31 causes the guide image creation unit 53 to create the guide image 72 and causes the display unit 50 to display the guide image 72 (S5).

  Further, when it is determined in step S4 that the subject 30 is located within the focusing range (range A) of the photographing unit 4 (for example, when the subject 30 comes closer by looking at the guide image 72), the control is performed. The unit 31 causes the guidance image creation unit 53 to create the guidance image 71 and causes the display unit 50 to display the guidance image 71 (S6).

  Furthermore, when it is determined in step S4 that the subject 30 is in the vicinity (range C) of the in-focus range of the photographing unit 4 (such as when the subject 30 is too close), the control unit 31 displays the guidance image. The creation unit 53 creates the guidance image 73 and causes the display unit 50 to display the guidance image 73 (S7).

  Next, the control unit 31 causes the photographing unit 4 to start photographing an eye image of the subject 30 (S8). Imaging by the imaging unit 4 is continuously performed.

  Then, the control unit 31 causes the eye image evaluation unit 3 to perform eye image evaluation processing (capture processing) (S9), the image quality determination unit 9 determines that the image quality is good, and the eye detection unit 10 If the eye image determined to be photographed is captured, the process proceeds to step S11, and if not, the process returns to step S4 (S10).

  In step S <b> 9, when the eye image is captured, the captured eye image is sent to the authentication processing unit 17. In the iris detection unit 11 of the authentication processing unit 17, an image of the iris part excluding the eyelid and white-eye parts from the eye image is cut out and sent to the authentication information creation unit 19 (S11).

  The authentication information creation unit 19 creates authentication information from the iris image by a predetermined method and sends it to the mismatch degree calculation unit 20 (S12).

  The mismatch degree calculation unit 20 compares the authentication information created by the authentication information creation unit 19 with the registered authentication information stored in advance in the storage unit 21, and calculates an HD value representing the degree of mismatch. The result is sent to the result determination unit 22 (S13).

  The authentication result determination unit 22 compares the HD value calculated by the discrepancy degree calculation unit 20 with a predetermined threshold value HDth to determine whether or not the subject 30 can be authenticated as a previously registered person. Determine (S14). And the determination result is output from the output part 23, and a process is complete | finished (S15).

  In the imaging device 60 and the authentication device 1 according to the present embodiment, the positional relationship between the display unit 50 and the imaging unit 4 is not particularly mentioned, but it is preferable that the subject 30 be positioned as close as possible. Even when approaching the apparatus while looking at 50, it is desirable because the photographing unit 4 can easily photograph the eye of the subject 30 in the center of the image. However, in the case where the display unit 50 and the photographing unit 4 are provided separately, when the subject 30 approaches while viewing the display unit 50, the eyes are inevitably shifted from the center of the image. In order to avoid this, it is possible to adopt a configuration as shown in FIG.

  FIG. 7 is a diagram illustrating another configuration of the display unit in the imaging device or the authentication device according to the embodiment of the present invention. In the example illustrated in FIG. 7, the display unit 150 includes four display devices 151 to 154, and each display device 151 to 154 is attached so as to surround the photographing unit 4. By using such a configuration to display the guide images 71 to 73 on the four display devices 151 to 154 as a whole, a configuration in which the above-described deviation does not occur even when the subject 30 approaches the apparatus is realized. be able to.

  In the authentication device 1 according to the embodiment of the present invention, the functions of the eye image evaluation unit 3 and the authentication processing unit 17 can be realized by either hardware or software. When each function is realized by hardware, the speed can be further increased, and a description that realizes each function by software is executed by a computer so that it can be easily modified. A highly configurable configuration can be realized.

  In the authentication apparatus according to the embodiment of the present invention, the example using the iris authentication method has been described as the method used for the authentication process, but the present invention is not limited to this method. Needless to say, the present invention can also be applied to an authentication method using an image obtained by photographing the subject's eyes, for example, retina authentication.

  As described above, according to the present invention, since the subject can be guided in both the distance direction from the apparatus and the vertical and horizontal directions, it is possible to use the eye image of the subject. The present invention is useful as an authentication apparatus for performing personal authentication, and more specifically, as an imaging apparatus that guides an eye of a subject to an appropriate position for imaging, an authentication apparatus using the imaging apparatus, and an imaging method.

The front view which looked at the authentication apparatus in embodiment of this invention from the front The figure for demonstrating the positional relationship of the imaging | photography apparatus or authentication apparatus in embodiment of this invention, and a to-be-photographed object. The figure for demonstrating the display with respect to the to-be-photographed object of the imaging device or authentication apparatus in embodiment of this invention The figure which shows the relationship between the enlargement ratio and reduction ratio in the guide image creation part of the imaging device or authentication device in the embodiment of the present invention, and the distance from the imaging device to the subject The block diagram for demonstrating the structure of the authentication apparatus in embodiment of this invention. The figure for demonstrating operation | movement of the authentication apparatus in embodiment of this invention The figure which shows another structure of the display part in the imaging device or authentication apparatus in embodiment of this invention

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Authentication apparatus 2 Distance measurement part 3 Eye image evaluation part 4 Imaging | photography part 7 Light source part 9 Image quality determination part 10 Eye detection part 11 Iris detection part 17 Authentication processing part 19 Authentication information creation part 20 Inconsistency degree calculation part 21 Storage part 22 Authentication result Determination unit 23 Output unit 30 Subject 31 Control unit 50, 150 Display unit 52 Determination unit 53 Guide image creation unit 60 Imaging device 71, 72, 73 Guide image 151, 152, 153, 154 Display device

Claims (13)

A photographing unit for photographing at least eyes of a subject;
A distance measuring unit that repeatedly measures the distance to the subject;
A determination unit that determines whether or not the subject is in a focusing range of the photographing unit based on a distance to the subject measured by the distance measurement unit;
A guide image creating unit for creating a guide image of the subject;
When the determination unit determines that the subject is in the focus range, the image of the subject is displayed. When the determination unit determines that the subject is not in the focus range, An imaging apparatus comprising: a display unit that displays the guide image created by the guide image creation unit. The determination unit further determines whether the subject is closer or farther than the in-focus range of the photographing unit,
The guide image creation unit creates an enlarged and blurred enlarged guide image of the eye of the subject,
The imaging apparatus according to claim 1, wherein the display unit displays the enlarged guidance image when the determination unit determines that the subject is closer to the in-focus range. The determination unit further determines whether the subject is closer or farther than the in-focus range of the photographing unit,
The guide image creating unit creates a reduced and blurred reduced guide image of the eye of the subject,
The imaging apparatus according to claim 1, wherein the display unit displays the reduced guidance image when the determination unit determines that the subject is far from the focus range. The photographing apparatus according to claim 2, wherein the enlarged guide image is a black and white image, and the image of the subject is a color image. The photographing apparatus according to claim 3, wherein the reduced induction image is a black and white image, and the image of the subject is a color image. The imaging according to claim 2 or 4, wherein the guide image creating unit determines an enlargement ratio of the enlarged guide image based on a distance to the subject measured by the distance measuring unit. apparatus. The imaging apparatus according to claim 6, wherein the guide image creation unit increases the enlargement ratio of the enlarged guide image as the distance to the subject is shorter. The imaging according to claim 3 or 5, wherein the guide image creating unit determines a reduction rate of the reduced guide image based on a distance to the subject measured by the distance measuring unit. apparatus. The imaging apparatus according to claim 8, wherein the guide image creating unit increases the reduction ratio of the reduced guide image as the distance to the subject increases. The photographing apparatus according to any one of claims 1 to 9,
An eye image evaluation unit that evaluates an eye image of the subject imaged by the imaging unit of the imaging device;
An authentication apparatus comprising: an authentication processing unit that performs an authentication process on the eye image based on a result of the evaluation performed by the eye image evaluation unit. The authentication processing unit
An authentication information creating unit that creates authentication information from a portion including at least an iris of an image photographed by the photographing unit;
A storage unit for storing registration authentication information of a person registered in advance;
A mismatch degree calculating section for calculating a mismatch degree between the authentication information created by the authentication information creating section and the registered authentication information stored in the storage section;
And an authentication result determination unit that determines whether or not the subject can be authenticated as the person registered in advance by comparing the mismatch calculated by the mismatch calculation unit with a predetermined threshold. The authentication device according to claim 10. The eye image evaluation unit includes: an image quality determination unit that determines image quality of the eye image of the subject imaged by the imaging unit; and an eye detection unit that determines whether or not an eye is captured in the eye image Prepared,
11. The authentication processing unit performs authentication processing using an eye image that is determined by the image quality determination unit to be good in image quality, and that the eye detection unit determines that an eye is being photographed. Or the authentication apparatus of Claim 11. A first step of photographing at least eyes of a subject with a photographing unit;
A second step of repeatedly measuring the distance to the subject;
A third step of determining whether or not the subject is in a focusing range of the photographing unit based on the distance to the subject measured in the second step;
A fourth step of creating a guide image of the subject;
In the third step, when it is determined that the subject is in the focusing range, an image of the subject is displayed. In the third step, it is determined that the subject is not in the focusing range. And a fifth step of displaying the guide image created in the fourth step.

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