JP2006163683A - Eye image imaging device and authentication device using it - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an eye image imaging device capable of implementing using a simple arrangement a rapid process on a plurality of persons of varying heights to be authenticated; and to provide an authentication device using the imaging device. <P>SOLUTION: The eye image imaging device includes a first imaging part 3 for imaging a person to be authenticated; a second vertically rotatable imaging part 4; a distance calculating part 51 for calculating the distance to the person; a height information calculating part 52 for calculating information on the position of the eyes of the person on the basis of the distance to the person and the image of the person taken by the first imaging part 3; a direction predicting part 53 for predicting the direction in which to point the second imaging part 4 on the basis of the information on the position of the eyes of the person calculated by the height information calculating part 52, so that when the person approaches, the eyes of the person are at the focal position of the second imaging part 4; and a tilt drive part 5 for pointing the second imaging part 4 in the direction predicted by the direction predicting part 53 in which to point the second imaging part 4. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an eye image capturing apparatus that captures an image including at least eyes of a person to be authenticated and an authentication apparatus using the eye image capturing apparatus.

  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.

  Generally, in the iris authentication method, it is necessary to capture a clear eye image of the person to be authenticated by a camera equipped with a telephoto lens. However, in stationary devices such as entrance / exit management devices, a plurality of persons to be authenticated are authenticated, and the height difference for each person to be authenticated is large at that time. In a state where the shooting direction is fixed, it is difficult to capture an eye image of a tall person to be authenticated or, conversely, a short person to be authenticated.

In order to solve such a problem, for example, a plurality of telephoto cameras are arranged in the height direction of the person to be authenticated, and an eye image is included from a plurality of images photographed by each camera. An authentication method has been proposed in which an image determined to be selected is selected and authentication information is created from the image, thereby making it less susceptible to the height difference of each person to be authenticated. 2).
Japanese Patent No. 3307936 Japanese Patent Laid-Open No. 2001-184483

  However, in the conventional authentication method as described above, there is a problem that there is a high possibility that the apparatus becomes large because it is necessary to arrange a large number of telephoto cameras.

  Further, in the conventional authentication method as described above, since it is necessary to perform a heavy load process of detecting an eye image from a plurality of images, there is a problem that a rapid process is difficult.

  The present invention has been made in view of such a problem, and an eye image photographing apparatus capable of performing a quick process with a simple configuration on a plurality of persons to be authenticated having a height difference and the use thereof. It is an object to provide an authentication device.

  The eye image photographing device of the present invention measures a distance to a first person, a first photographing part that photographs the person to be authenticated, a second photographing part that can rotate at least in the height direction of the person to be authenticated, and the person to be authenticated. The position information indicating the height of the eye of the person to be authenticated is calculated from the distance measuring unit to be measured, the distance to the person to be authenticated measured by the distance measuring unit, and the image of the person to be authenticated photographed by the first photographing unit. When the person to be authenticated approaches from the position information of the eye of the person to be authenticated calculated by the eye position information calculation unit and the eye position information calculation unit, the eye of the person to be authenticated is the focal position of the second photographing unit A direction prediction unit that predicts the direction in which the second imaging unit should be directed, and a drive unit that directs the second imaging unit in the direction in which the second imaging unit predicted by the direction prediction unit is directed. The second imaging unit captures an image including at least eyes of the person to be authenticated. That.

  According to such a configuration, the position of the eye of the person to be authenticated is calculated from the distance at the distance measuring unit and the image of the person to be authenticated taken by the first photographing unit, and the person to be authenticated is approached when approaching. Since the second photographing unit is directed so that the eyes of the second photographing unit are positioned at the focal position of the second photographing unit, it is possible to perform a quick process with a simple configuration on a plurality of authenticated persons having height differences. Possible configurations can be realized.

  The first photographing unit may be a wide-angle camera, and the second photographing unit may be a telephoto camera that captures an image with a narrower angle of view than the first photographing unit.

  According to such a configuration, since the wide-angle camera is used as the first photographing unit, it is possible to photograph the person to be authenticated within a relatively wide angle of view, and the narrow-angle camera as the second photographing unit. A sharp eye image can be taken by using.

  The distance measuring unit is configured to detect distance information between both eyes in the image of the person to be authenticated photographed by the first imaging unit and measure the distance to the person to be authenticated based on the distance information. May be.

  According to such a configuration, the distance to the person to be authenticated can be further measured by a simple method of detecting the distance between both eyes of the person to be authenticated from the image taken by the first photographing unit. A possible configuration can be realized.

  Furthermore, the distance measuring unit has a distance measuring sensor unit, and when the distance information between both eyes cannot be detected in the image of the person to be authenticated photographed by the first imaging unit, the distance measuring sensor The structure which measures the distance to a to-be-authenticated person based on the output from a part may be sufficient.

  According to such a configuration, it is possible to measure the distance to the person to be authenticated even when the person to be authenticated cannot photograph both eyes for some reason such as closing his eyes.

  The image capturing unit includes an image quality determination unit that determines the image quality of the image captured by the second image capturing unit. The second image capturing unit repeatedly captures an image including at least the eye of the person to be authenticated. It may be configured to output an image determined to be good.

  According to such a configuration, when the driving unit rotates the second imaging unit, the second imaging unit repeatedly performs imaging, and an image with good image quality is output. It is possible to realize a configuration with a high possibility of capturing a high-quality image even during movement such as when the person to be authenticated approaches.

  Furthermore, the image quality determination unit includes a focus degree calculation unit that calculates a focus degree of an image captured by the second image capturing unit, and the second image capturing unit captures an image including at least the eye of the person to be authenticated. The image quality determination unit may be configured to output an image in which the focus degree calculated by the focus degree calculation unit is higher than a predetermined threshold.

  According to such a configuration, when the driving unit rotates the second imaging unit, the second imaging unit repeatedly performs imaging. For example, when the person to be authenticated approaches Even during such movement, it is possible to realize a configuration that is highly likely to capture a focused image.

  In addition, the image capturing apparatus includes an eye detection unit that determines whether an image is captured by the second image capturing unit, and the second image capturing unit repeatedly captures an image including at least the eye of the person to be authenticated. It may be configured to output an image determined to be taken by the eye detection unit.

  According to such a configuration, when the driving unit rotates the second imaging unit, the second imaging unit repeatedly performs imaging, so that, for example, the person to be authenticated is blinking. Even in such a state, it is possible to capture an image with sufficiently wide eyes, that is, an image suitable for authentication processing.

  Furthermore, when the second image capturing unit repeatedly performs image capturing and an image in which it is determined that the eye is imaged by the eye detecting unit cannot be obtained, the second image capturing unit is connected to the drive unit. It may be configured to include a control unit that instructs to move the direction within a predetermined range.

  According to such a configuration, when the eye is not found in the image photographed by the second photographing unit, the peripheral portion can be photographed. Even when the angle of view of the second imaging unit deviates to some extent, it is possible to realize a configuration that is highly likely to capture an eye image.

  Moreover, the structure provided with the guidance | guide part which guide | induces so that it may arrange | position an eye position with respect to a to-be-authenticated person in the focus position of a 2nd imaging | photography part may be sufficient.

  According to such a configuration, for example, when the person to be authenticated approaches, the position of his / her eyes can be moved to the focal position of the second imaging unit by guidance of the guidance unit. Since it becomes possible, an eye image can be taken more reliably.

  Moreover, the structure which has a mirror part which projects a to-be-authenticated person's eyes may be sufficient as a guidance | induction part.

  According to such a configuration, the person to be authenticated can further reliably capture an eye image by moving so that his / her own eye is reflected on the mirror.

  Further, the guide unit may have a mark unit that guides the person to be authenticated so that both eyes of the person to be authenticated are arranged in the frame of the mirror part.

  According to such a configuration, it is possible to realize a configuration that can easily guide both eyes of the person to be authenticated.

  Next, an authentication apparatus according to the present invention includes an eye image capturing device according to the present invention and an authentication information creating unit that creates predetermined authentication information from an image including at least the eye of the person to be authenticated photographed by the second photographing unit. Created by the registered authentication information and the authentication information creation unit as a result of the comparison and collation by the collation unit. And an authentication unit that authenticates that the person to be authenticated is a person registered in advance when it is determined that the authentication information matches.

  According to such a configuration, an eye image capturing device capable of performing a quick process with a simple configuration is used for a plurality of authenticated persons having a height difference, and the captured image is used. Since the authentication process is performed, a configuration capable of performing a quick process with a simple configuration can be realized.

  The authentication information creating unit creates authentication information from an image of the iris part of the eye by a predetermined method from an image including at least the eye of the person to be authenticated, and the registered authentication information is the iris of the eye of the person registered in advance. The configuration may be information created from a partial image by a predetermined method.

  According to such a configuration, authentication information is created using an image of the iris portion of the eye, and authentication processing is performed using the authentication information, so that a configuration capable of highly accurate authentication is realized. be able to.

  As described above, by using the eye image photographing device of the present invention and the authentication device using the same, it is possible to perform a quick process with a simple configuration for a plurality of authentication subjects having a height difference. An eye image capturing device and an authentication device using the same can be provided.

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

(Embodiment)
First, the authentication device 1 according to the embodiment of the present invention will be described. FIG. 1 and FIG. 2 are diagrams for explaining functions of the authentication device 1 according to the embodiment of the present invention. In the embodiment of the present invention, in order to simplify the explanation, three axial directions (X-axis direction, Y-axis direction, and Z-axis direction) orthogonal to each other are shown in the drawing. Note that the X-axis direction is the horizontal direction (rightward from the authentication device 1 toward the person to be authenticated 30) as viewed from the person who should be authenticated by the authentication apparatus 1 (hereinafter referred to as the person to be authenticated) 30. Indicates the height direction of the person to be authenticated 30 (the upward direction from the authentication device 1 toward the person to be authenticated 30), and the Z-axis direction indicates the person to be authenticated. The distance direction connecting the person 30 and the authentication apparatus 1 (the direction from the authentication apparatus 1 toward the person 30 to be authenticated is a positive direction) is shown.

In the embodiment of the present invention, a case where the person 30 to be authenticated approaches the authentication apparatus 1 (a case where the person 30 to be authenticated has moved in the direction A in FIG. 1) will be described as an example. Figure 1 shows a case where the person to be authenticated 30 is located relatively far from the authentication device 1 (if you are in the position of the distance D ₂ in the drawing). FIG. 2 shows a state in which the person 30 to be authenticated is located relatively close to the authentication apparatus 1, takes an eye image, and is subjected to authentication processing (when the person is at a distance D _{3 in} the drawing). .

As shown in FIG. 1 or FIG. 2, the authentication device 1 according to the embodiment of the present invention is attached to the wall surface portion 60, and the distance measuring sensor unit 2 that measures the distance to the person 30 to be authenticated (see FIG. 1 and FIG. 2). (Not shown in FIG. 2), a first imaging unit 3 that captures a wide-angle image that captures at least both eyes of the person 30 to be authenticated, and a first image that captures an eye image around the eye 31 of the person 30 to be authenticated. 2, the tilting unit 6 on which the distance measuring sensor unit 2 and the second imaging unit 4 are mounted, and the tilting unit 6 at least in the tilt direction (the α direction in FIG. 1 and the height direction of the person 30 to be authenticated). The distance calculation unit 51 for calculating the distance D ₂ from the output value from the tilt driving unit 5, the distance measurement sensor unit 2, or the wide-angle image captured by the first imaging unit 3 to the person 30 to be authenticated, the distance D ₂ is used to measure the height from the floor surface to the eye 31 of the person 30 to be authenticated. Height information calculating unit 52 for calculating a height D _1, from a height D _1, if the second imaging unit 4 mounted on the tilt portion 6, close to the state in which the person to be authenticated 30 is shown in FIG. 2 Furthermore, the direction predicting unit 53 that predicts the direction (angle θ in FIG. 2) to be suitable for photographing the position of the eye 31 and the tilt drive so that the tilt unit 6 is rotated in the angle θ tilt direction described above. The control part 50 which controls the part 5 is provided.

  Here, each component of the authentication apparatus 1 in embodiment of this invention is demonstrated in detail.

  First, as the distance measuring sensor unit 2, a sensor capable of measuring an object using infrared rays can be used. In the embodiment of the present invention, a sensor capable of measuring a distance from 20 cm to 100 cm is used. The distance measuring sensor unit 2 according to the embodiment of the present invention is disposed in the tilt unit 6 so that the optical axis of the infrared rays emitted from the distance measuring unit 2 faces substantially the same direction as the direction of the imaging optical axis of the second imaging unit 4. . Therefore, the ranging optical axis of the ranging sensor unit 2 changes in the height direction of the person 30 to be authenticated as the tilt unit 6 rotates.

  As the first photographing unit 3, various cameras such as a monitoring camera can be used as long as the person 30 can be photographed when the person 30 to be authenticated is located about 1.5 m from the authentication device 1. A known camera can be used. In the embodiment of the present invention, a lens system of a fixed focal point (capable of photographing from 30 cm to infinity) having a horizontal field angle of 51 °, a maximum aperture ratio F2.1, and a focal length of 3.7 mm is mounted, and the resolution is VGA ( A color camera equipped with a CCD (horizontal 640 pixels × vertical 480 pixels) was used as the first photographing unit 3. Note that in the authentication device 1 according to the embodiment of the present invention, the height of the eye 31 of the person 30 to be authenticated is about 1200 mm to 1820 mm in order to capture an eye image of the person 30 to be authenticated having the widest possible height difference. The authentication device 1 is attached to the wall surface portion 60 so that the position of the optical axis of the first imaging unit 3 is about 1510 mm, which is an intermediate value from the floor surface, so that the range can be imaged. Further, in the embodiment of the present invention, the optical axis direction of the first imaging unit 3 of the authentication device 1 is the horizontal direction (Z-axis direction).

  The second photographing unit 4 is equipped with a telephoto lens for photographing the iris part of the eye 31 of the person 30 to be authenticated with good contrast, and the light source unit 7 (not shown in FIGS. 1 and 2). Thus, it is possible to use a black and white camera capable of photographing near-infrared light irradiated on the eye 31 of the person 30 to be authenticated. In the embodiment of the present invention, there are two monochrome cameras (right eye) equipped with a fixed focus telephoto lens system having a horizontal angle of view of 6.8 ° and a maximum aperture ratio of 11.0, and a CCD having a resolution of VGA. And left eye). The second imaging unit 4 according to the embodiment of the present invention has a desirable imaging distance D from the second imaging unit 4 to the eye 31 of the person 30 to be authenticated shown in FIG. The range is 41.6 mm horizontal x 31.2 mm vertical.

  A known motor such as a stepping motor or an ultrasonic motor can be used as the tilt driving unit 5 that rotationally drives the tilt unit 6, but a motor that can control the rotation angle by using a configuration having an encoder or the like. Is used. In the embodiment of the present invention, the tilt unit 6 is rotatably provided by driving the tilt drive unit 5.

  The authentication device 1 according to the embodiment of the present invention can adjust the allowable range of the height of the person 30 to be authenticated by adjusting the rotation angle of the tilt unit 6 and the installation height of the authentication device 1. Note that the rotation angle of the tilt unit 6 of the authentication device 1 in the embodiment of the present invention is 35 ° in the elevation direction (upward) and 15 ° in the depression direction (downward).

  Here, the configuration of the tilt unit 6 in the embodiment of the present invention will be described in detail. FIG. 3 is a front view showing the configuration of the tilt unit 6 of the authentication device 1 according to the embodiment of the present invention, and FIG. 4A is a side view showing the configuration of the tilt unit 6 according to the embodiment of the present invention. FIG. 4B is a plan view thereof.

  As shown in FIG. 3, FIG. 4 (a) and FIG. 4 (b), the tilt portion 6 of the authentication device 1 in the embodiment of the present invention has a hollow, substantially semi-cylindrical shape, and distance measurement is performed on the inside thereof. A sensor unit 2, a pair of second imaging units 4, and a pair of light source units 7 are stored. Further, at both ends of the tilt portion 6 (both ends in the X-axis direction in the drawing), there are formed a drive shaft 9 which is an axis when rotated by the tilt drive portion 5 and a shaft 8 on the opposite side. ing. The drive shaft 9 is pivotally supported by the tilt drive unit 5, and the shaft 8 is pivotally supported by a bearing (not shown) provided in the casing of the authentication device 1. The center axes of the drive shaft 9 and the shaft 8 are substantially coincident with each other, and the position of the center axis (hereinafter, this axis is referred to as a tilt axis) is viewed from the person 30 to be authenticated as shown in FIG. The second imaging unit 4 is provided at a position that passes through the lens optical axis.

  With such a configuration, the tilt unit 6 of the authentication apparatus 1 according to the embodiment of the present invention causes the lens light of the second photographing unit 4 in the height direction with respect to the authentication subject 30 by the rotation of the tilt drive unit 5. It is possible to rotate in the tilt direction with the position passing through the axis as the center of rotation.

  Further, the tilt unit 6 of the authentication device 1 according to the embodiment of the present invention stores the distance measuring sensor unit 2, the second imaging unit 4, and the light source unit 7, and faces the person 30 to be authenticated. A panel portion 35 is disposed on the power surface. The panel unit 35 is an optical filter that transmits light in the near-infrared region and absorbs light in the visible light region to some extent, and includes the ranging sensor unit 2, the second imaging unit 4, and the light source unit 7 from the person to be authenticated 30. It has a function to prevent the structure from being visible. This is because if the structure of the distance measuring sensor unit 2, the second photographing unit 4, and the light source unit 7 is seen from the person 30 to be authenticated, the person 30 is intimidated and it is difficult to authenticate with peace of mind. Because.

  Further, the authentication device 1 according to the embodiment of the present invention is an iris authentication device, and it is necessary to clearly photograph the iris pattern of the eye 31 of the person 30 to be authenticated. Therefore, as the light source unit 7 of the authentication device 1 according to the embodiment of the present invention, near-infrared light (wavelength of about 700 to 1000 nm) disposed so as to irradiate the vicinity of the eye 31 of the person 30 to be authenticated. Two light sources (for the right eye and for the left eye) were used.

  Furthermore, the tilt unit 6 of the authentication apparatus 1 according to the embodiment of the present invention guides the subject 30 to guide the position of his / her eyes 31 to an appropriate position at the substantially central portion of the panel unit 35. The unit 10 is provided. The guiding unit 10 moves the mirror unit 12 for the person to be authenticated 30 to reflect his / her eyes 31 and the image of the black eye part of the person's eyes 31 to enter the region in the mirror part 12. The substantially elliptical mark portion 11 is provided. The mark part 11 is formed on the surface of the mirror part 12 by a method such as printing.

  Here, a method for guiding the eye 31 of the person 30 to be authenticated by the guide unit 10 of the authentication device 1 according to the embodiment of the present invention will be described in detail. FIG. 5A is a diagram illustrating a configuration of the guiding unit 10 of the authentication device 1 according to the embodiment of the present invention, and FIG. 5B illustrates a method for guiding the person 30 to be authenticated by the guiding unit 10. It is a figure for doing.

  As shown in FIG. 5B, in the authentication device 1 according to the embodiment of the present invention, the person 30 to be authenticated looks at the mark part 11 of the guiding part 10 with both his / her eyes 31. Then, as shown in FIG. 5B, the right eye 33 sees the virtual image 38 beyond the mirror part 12 due to the reflection at the mirror part 12, while the left eye 32 sees the mirror part. The virtual image 37 on the other side of 12 is seen. In this state, the person 30 to be authenticated moves to a position where the black eyes of the right eye 33 and the left eye 32 of each person enter the elliptical shape of the mark unit 11, thereby the right eye of the person 30 to be authenticated. 33 and the left eye 32 are guided in the X-axis direction and the Y-axis direction in FIG. 5, and the right eye 33 and the left eye 32 are located near the front of each of the pair of second imaging units 4. . The guidance in the Z-axis direction is performed using the output from the distance measuring sensor unit 2 so that the distance to the person to be authenticated 30 is the optimum shooting distance of the second shooting unit 4. This can be done by guiding. By photographing with the second photographing unit 4 in this state, good eye images of the right eye 33 and the left eye 32 can be photographed. FIG. 6 is a diagram illustrating an example of the eye image 41 of the right eye 33 and the eye image 40 of the left eye 32 captured by the second imaging unit 4 of the authentication device 1 according to the embodiment of the present invention. As described above, by using the guiding unit 10 of the authentication device 1 according to the embodiment of the present invention, the right eye 33 and the left eye 32 of the person 30 to be authenticated are positioned near the front of each of the pair of second imaging units 4. Therefore, the eye images of the right eye 33 and the left eye 32 of the person 30 to be authenticated can be taken. In the eye image capturing device and the authentication device of the present invention, the configuration of the guiding unit 10 is not limited to the above example, and the position of the eye 31 of the person 30 to be authenticated (one eye or both eyes). Other known methods can be used as long as they can be induced). For example, as shown in Japanese Patent Application Laid-Open No. 2004-46451, a method of photographing both eyes with a pair of photographing units whose optical axes are crossed in a state where the mark 30 is viewed by both eyes of the person 30 to be authenticated. It is also possible to use.

  Here, the contents of the processing in the authentication device 1 in the embodiment of the present invention will be described in detail. FIG. 7 is a block diagram illustrating functional blocks of the authentication device 1 according to the embodiment of the present invention.

  As shown in FIG. 7, the authentication device 1 according to the embodiment of the present invention is mounted on the above-described components, that is, the distance measuring sensor unit 2, the first imaging unit 3, the tilt unit 6, and the tilt unit 6. The pair of second imaging unit 4, the pair of light source unit 7, the tilt driving unit 5 that rotates the tilt unit 6 in the tilt direction, the control unit 50, the distance calculation unit 51, the height information calculation unit 52, and the direction prediction unit 53. In addition to this, a process of selecting an image that can be used for authentication using the eye images 40 and 41 captured by the second imaging unit 4 and sending the selected image to the authentication processing unit 17 (hereinafter, this process is referred to as a capture process). ), The authentication processing unit 17 that performs iris authentication processing using the image captured by the capture processing unit 14, and the authentication processing unit 17 as a result of the authentication processing. Registered And an output unit 23 for outputting whether it. Note that the processes of the capture processing unit 14 and the authentication processing unit 17 are controlled by the control unit 50, and each process can be repeatedly performed according to an instruction from the control unit 50.

  The capture processing unit 14 determines the image quality from the eye images 40 and 41 input from the pair of second imaging units 4, and the image quality determined by the image quality determination unit 15 is good. It has an eye detection unit 16 that detects whether or not there is an eye inside.

  For example, the image quality determination unit 15 integrates predetermined high-frequency components from the eye images 40 and 41, and if the amount of the high-frequency components is larger than a predetermined threshold, the eye images 40 and 41 are in focus. An in-focus degree determination unit that determines that the image is present can be used. In addition, the image quality determination unit 15 performs various image quality evaluation processes such as a luminance evaluation unit that measures the average luminance of the eye images 40 and 41 and evaluates whether the image is too bright or too dark. Blocks can be used. Further, these processing blocks can be used in combination.

  Further, as a method of realizing the function of the eye detection unit 16, for example, in the eye images 40 and 41, a round area estimated to be a pupil or a black eye part (for example, round and has a lower luminance than the surrounding area). A region matching method is used to perform pattern matching processing between the eye images 40 and 41 and a black (low luminance) image of a predetermined size, or the position of a pupil candidate from the eye images 40 and 41. And a luminance difference calculation unit for obtaining a difference between a maximum value and a minimum value of the luminance of the eye image on a circle having a predetermined radius centered on the center coordinates of the pupil candidate. A method of determining that the pupil candidate is a pupil when the output of the luminance difference calculation unit is within a predetermined threshold can be used. Although detailed description is omitted, the processing of the image quality determination unit 15 and the eye detection unit 16 can be realized by either software or hardware. It is possible to perform capture processing at intervals. When the 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 the center is within the predetermined range, the eye detection unit 16 When the method for determining that the candidate is a pupil is used, the value of the difference between the maximum value and the minimum value of the luminance on the circumference of the eye image can be used for the image quality determination of the image quality determination unit 15. It is.

  The authentication processing unit 17 performs processing on an image determined by the capture processing unit 14 that the image quality determination unit 15 determines that the image quality is good and the eye detection unit 16 determines that a pupil or a black eye portion exists in the image. Do. The authentication processing unit 17 of the authentication device 1 according to the embodiment of the present invention includes an iris detection unit 18 that cuts out an iris portion from the image output from the capture processing unit 14, and an image of the iris portion cut out by the iris detection unit 18. Authentication information creation unit 19 for creating authentication information to be used for authentication processing by a predetermined method, storage unit 21 for storing registration authentication information of a person registered in advance, registration authentication information and authentication stored in storage unit 21 Based on the collation unit 20 for comparing and collating the authentication information created by the information creation unit 19 and the collation result in the collation unit 20, it can be authenticated that the person to be authenticated 30 is a person registered in advance. An authentication result determination unit 22 for determining Although detailed description is omitted, the processes of the iris detection unit 18, the authentication information creation unit 19, the verification unit 20, and the authentication result determination unit 22 can be realized by either software or hardware. By using hardware, authentication processing can be performed at a cycle of about 200 ms.

  Here, a method of detecting an iris from an image in the iris detection unit 18, a method of generating authentication information from an image of an iris part in the authentication information generation unit 19, a method of comparison and verification in the verification unit 20, and an authentication result determination unit 22 For example, the method disclosed in Patent Document 1 described above can be used as the method for determining the authentication result in (1). In the authentication apparatus of the present invention, the authentication processing method in the authentication processing unit 17 is not limited to the above-described method. For example, it is possible to use a method in which the authentication processing unit 17 directly compares and collates the image sent from the capture processing unit 14 with the image stored in advance in the storage unit 21 without creating authentication information. It is. However, in view of the speed of processing, reliability, and the like, it is desirable to use the method described in Patent Document 1 in practice.

  Note that in the authentication device 1 according to the embodiment of the present invention, the authentication result determination unit 22 in the authentication processing unit 17 determines that either the right eye 33 or the left eye 32 of the person 30 to be authenticated matches the registered authentication information. The configuration may be such that the person to be authenticated 30 is authenticated as a person who has been registered in advance, and if both the right eye 33 and the left eye 32 of the person to be authenticated 30 match the registered authentication information. The configuration may be such that the authenticator 30 authenticates that the person is registered in advance. In the former case, it is possible to provide the authentication device 1 capable of reducing the identity rejection rate, and in the latter case, it is possible to provide the authentication device 1 capable of reducing the acceptance rate of others. Can be selected according to the request.

  Further, as the output unit 23 of the authentication device 1 in the embodiment of the present invention, for example, a well-known display unit such as a liquid crystal display device, a unit that can notify the authentication result 30 to the user 30 by voice, Furthermore, various known output means such as means capable of transmitting a signal to an externally connected server device or the like can be used.

  Furthermore, the authentication device 1 according to the embodiment of the present invention includes a light source driving unit 13 that is connected to the control unit 50 and drives the light source unit 7 to turn on, turn off, or blink.

  Further, as shown in FIG. 7, the first imaging unit 3, the distance measuring sensor unit 2, and the distance calculating unit 51 constitute a distance measuring unit 54.

  In the authentication device 1 according to the embodiment of the present invention, when the light source driving unit 13 irradiates the eye 31 of the person 30 to be authenticated, the electronic shutter of the second imaging unit 4 and It is desirable from the viewpoint of reducing power consumption to perform irradiation while flashing in synchronization.

  Here, functions of the distance calculation unit 51 and the height information calculation unit 52 of the authentication device 1 according to the embodiment of the present invention will be described in detail. FIG. 8A, FIG. 8B, and FIG. 9 are diagrams for explaining functions of the distance calculation unit 51 and the height information calculation unit 52 of the authentication device 1 according to the embodiment of the present invention, respectively. FIG. 8A and FIG. 8B are diagrams illustrating a coordinate system for explaining the functions of the distance calculation unit 51 and the height information calculation unit 52 of the authentication device 1 according to the embodiment of the present invention. FIG. 9 is a diagram illustrating an example of a wide-angle image 65 photographed by the first photographing unit 3 for explaining the function.

The authentication device 1 according to the embodiment of the present invention includes a control unit so that the second photographing unit 4 faces the eye 31 when the person 30 to be authenticated approaches and is positioned as shown in FIG. The tilt drive unit 5 is controlled by 50 to rotate the tilt unit 6 in the tilt direction. Therefore, it becomes necessary to estimate the height D ₁ of the floor surface of the eye 31 of the person to be authenticated 30, as a premise, the distance calculation unit 51, the authentication apparatus in a state shown in FIG. 1 1 calculating the distance _{D 2} to the eye 31 of the person to be authenticated 30.

Here, it is assumed that the distance between the human right eye 33 and the left eye 32 is approximately constant. Then, it is possible to calculate from the difference of the coordinates in the horizontal direction (X-axis direction) of the right eye 33 and left eye 32 of the image captured by the wide-angle image 65, the distance D _2.

Now, a coordinate system as shown in FIGS. 8A and 8B is assumed. The angle γ indicates the angle of view in the horizontal direction (X-axis direction) of the first imaging unit 3, and the angle δ indicates the angle of view of the first imaging unit 3 in the vertical direction (Y-axis direction). Further, the distance between the actual right eye 33 and the left eye 32 of the person 30 to be authenticated is the distance D ₄ , and the distance from the first imaging unit 3 to the eye 31 of the person 30 to be authenticated is indicated by the distance D ₂ . .

Further, as described above, wide-angle image 65 captured by the first imaging unit 3 is VGA size, at a distance D _2, and the wide-angle image 65 as shown in FIG. 9 was taken. As shown in FIG. 9, in the wide-angle image 65, the distance on the coordinates of the right eye 33 and the left eye 32 is the distance p, and the average of the distances from the top of the screen to the right eye 33 and the left eye 32, respectively. Assume that the value is y.

Under these assumptions,
D ₂ × tan (γ / 2) × 2: 640 = D ₄ : p (1)
And
D ₂ = 640 × D ₄ / (2 × p × tan (γ / 2)) (2)
Holds.

Here, the distance D _4, as described above, assuming that there is no individual difference, as an example, substitutes the average value 64.1mm in equation (2). As the angle γ, the horizontal field angle (51 ° in the present embodiment) of the optical system of the first photographing unit 3 may be substituted into the equation (2). In this way, the distance calculation unit 51 can calculate the distance D _2.

  Although the present invention does not limit the method of calculating the distance p on the coordinates of the right eye 33 and the left eye 32 in the distance calculation unit 51, both eyes are detected from the image by pattern matching, The distance p can be calculated by using various known methods such as a distance calculation method for calculating the distance between the centers of the eyes. As an example, the method disclosed in Japanese Patent Application Laid-Open No. 2004-30552 can be used.

Next, the height information calculation unit 52 calculates the height (average value of both eyes) of the eye 31 of the person 30 to be authenticated. Here, the distance D ₁ represents the height from the floor surface to the eye 31 of the person 30 to be authenticated, the angle δ represents the angle of view of the first photographing unit 3 in the vertical direction (Y-axis direction), and the height h Represents the height from the floor surface to the center of the optical axis of the first imaging unit 3.

Under such a premise, first, the actual distance per pixel in the wide-angle image 65 shown in FIG. 9 is represented by (D ₄ / p).

Next, the height H ₁ from the optical axis center of the first imaging unit 3 to the eye 31 is
H ₁ = (240−y) × (D ₄ / p) (3)
Holds. Therefore,
D ₁ = h + (240−y) × (D ₄ / p) (4)
Holds.

Here, since the values of the height h, the distance D ₄ , and the distance p are known, the distance D ₁ can be calculated by substituting them into the equation (4).

Therefore, the height information calculation unit 52 can calculate the height D ₁ of the eye 31 of the person 30 to be authenticated from the wide-angle image 65 captured by the first imaging unit 3 as described above.

Height information calculating unit 52 sends the information of the height D ₁ calculated by the foregoing method in the directional prediction unit 53. The direction predicting unit 53 calculates an angle θ to rotate the tilt unit 6 on which the second imaging unit 4 is mounted from the obtained information of the distance D ₁ , and sends it to the tilt driving unit 5 via the control unit 50. Send it out. The tilt drive unit 5 can capture an image of the eye 31 by the second imaging unit 4 by rotating the tilt unit 6 in the tilt direction by an angle θ.

Here, with reference to FIG. 2, a method for calculating the angle θ from the distance D ₁ in the direction predictor 53.

As shown in FIG. 2, the optimum photographing distance of the second photographing unit 4 (strictly, the optimum photographing distance from the tilt axis to the subject) is a distance D, and the center of the tilt axis of the tilt unit 6 is The height from the floor is indicated by height h ′. Then
D ₁ −h ′ = D × sin θ (5)
Therefore,
θ = arcsin ((D ₁ −h ′) / D) (6)
Holds.

Here, the height D ₁ is output from the height information calculation unit 52, the height h ′ is determined when the authentication device 1 is attached to the wall surface portion 60, and the distance D is also the optical system of the second imaging unit 4. Determined from. Therefore, by substituting these values into the equation (6), it is possible to determine the angle θ at which the tilt unit 6 should be tilted.

In the embodiment of the present invention, the case where the optical axis direction of the first photographing unit 3 of the authentication apparatus 1 is installed in the horizontal direction (Z-axis direction) has been described as an example. Is not limited to the optical axis direction of the first imaging unit 3. For example, there are cases where it is practically desirable to install the upper portion or the lower portion of the wall surface portion 60 due to installation restrictions. In such a case, for example, when an angle formed by the optical axis direction of the first imaging unit 3 and the horizontal direction is an angle σ,
_{D 1 = ((240-y} ) × (D 4 / p) × cosσ) + (640 × D 4/2 × p × tan (γ / 2)) × sinσ + h) (7)
Is holds, by using equation (7), also in this case it is possible to calculate the height D ₁ of the eye 31.

  Next, operation | movement of the authentication apparatus 1 in embodiment of this invention is demonstrated. FIG. 10 is a flowchart showing the operation steps of the authentication device 1 in the embodiment of the present invention.

As shown in FIG. 10, when the authentication apparatus 1 according to the embodiment of the present invention is activated, the authentication apparatus 1 first starts photographing of the first photographing unit 3 (S1), and at the same time, the distance by the distance measuring sensor unit 2 Measurement is started (S2). When shooting in the first shooting section 3 is started, it is also started measured distance D ₂ to the authentication subject 30 by the distance measuring unit 51 (S4).

Control unit 50, the distance calculation unit 51 to the information of the distance _{D 2} is output, continuing the processing from step S1 to step S4 (S5). Note that, in order to obtain the information of the distance D ₂ is not always necessary to use a distance measuring sensor unit 2 to the distance measuring unit 54, the distance calculation unit 51, captured by the first imaging unit 3 wide information from the distance of the distance D ₂ between the eye 31 of the image 65 can be obtained. If the distance measuring sensor unit 2, information of the distance _{D 2} is obtained, the process proceeds to step S10 (S3). By using the distance measuring sensor unit 2 together, when the calculation process in the distance calculating unit 51 requires time, the person 30 to be authenticated approaches with the eye 31 closed, When the person 30 to be authenticated approaches from an oblique direction deviating from the angle of view of the first photographing unit 3, before the person 30 to be authenticated approaches the optimum photographing distance of the second photographing unit 4. In addition, since there is a possibility that the position of both eyes cannot be acquired from the wide-angle image 65, it is possible to realize a configuration that is more practical if the output of the distance measuring sensor unit 2 is used together.

Control unit 50, once the distance calculation unit 51 of the distance D ₂ information is output, the height information calculating unit 52, the person to be authenticated from the floor using a wide-angle image 65 captured by the first imaging section 3 to detect the distance _{D 1} of the height direction to the eye 31 of the 30 (S6).

From the height information calculating unit 52, when the information of the distance D ₁ is output, the process proceeds to the next step, if not output, the flow returns to step S1 and step S2, the wide-angle image 65 by the first imaging section 3 The photographing or the distance measurement by the distance measuring sensor unit 2 is performed again (S7).

In step S7, if the height information calculating unit 52, information of the distance D ₁ is output, directional prediction unit 53 uses the information of the distance D _1, the tilt unit 6 using equation (6) Is calculated and output to the controller 50 (S8). Next, the control unit 50 instructs the tilt driving unit 5 to rotate the tilt unit 6 by the angle θ tilt, and the tilt driving unit 5 rotates the tilt unit 6 by the angle θ tilt (S9). Here, the person 30 to be authenticated further approaches the authentication apparatus 1 to the state shown in FIG. 2, and the position where the second photographing unit 4 can photograph his / her eyes 31 by the guiding unit 10. Move to. Note that, in step S3, the distance measuring sensor unit 2, when information of the distance D ₂ is obtained, the person to be authenticated 30 by tilting the tilting part 6 manually, his eye 31 second The photographing unit 4 can take a picture.

  Next, the control unit 50 causes the second photographing unit 4 to start photographing the eye images 40 and 41 of the person 30 to be authenticated (S10). The eye images 40 and 41 photographed by the second photographing unit 4 are sent to the capture processing unit 14, where the image quality determination process by the image quality determination unit 15 and the eye detection process by the eye detection unit 16 are performed (S11).

If an image determined to have good image quality and an eye is present in the image is output from the capture processing unit 14, the process proceeds to the next step, and if not output, the process returns to step S 10 to return to the control unit 50. Causes the second photographing unit 4 to continue photographing until an image is output from the capture processing unit 14 (S12). If an image is not captured for a predetermined time, if the control unit 50 is configured to rotate the second imaging unit 4 in a tilt direction at a predetermined angle (for example, about ± 5 °), the height information calculation unit is slightly increased. even if the error in the distance D ₁ of the calculated eye 52 has occurred (e.g., errors due to walking), it is possible to reliably captured eye image.

  In step S12, when it is determined that an image determined that the image quality is good and the eye is present in the image is output from the capture processing unit 14, the image is sent to the authentication processing unit 17, and a predetermined authentication process is performed. Is performed (S13).

  In step S13, when the authentication processing in the authentication processing unit 17 is normally completed, the output unit 23 outputs the authentication result, and the authentication device 1 ends the processing (S15). On the other hand, if the authentication processing in the authentication processing unit 17 does not end normally in step S13, the control unit 50 returns to step S10, and the eye image 40, 41 of the person 30 to be authenticated is returned to the second photographing unit 4. Is resumed (S14).

  As described above, according to the authentication device 1 in the embodiment of the present invention, when the person 1 to be authenticated is located relatively far, the height information of the eye 31 of the person 30 to be authenticated is calculated. Then, from the height information of the eye 31, when the person 30 to be authenticated further approaches, the tilt unit 6 is rotated in advance to an angle at which authentication is most easily performed. The guidance by the guidance unit 10 can be performed. This makes it possible to perform a quick authentication process.

  In addition, according to the authentication device 1 in the embodiment of the present invention, the tilt unit 6 can be used by the user by automatically rotating the tilt unit 6 in advance as compared with the case where the tilt unit 6 is manually rotated. It becomes possible to reduce resistance.

  Furthermore, since the person to be authenticated 30 can easily perform the guidance by the guidance unit 10, it is possible to reduce the identity rejection rate.

  In the embodiment of the present invention, the example has been described in which the authentication device 1 authenticates the person using the iris authentication method. However, the authentication device of the present invention is limited to the iris authentication device. is not. For example, the present invention can also be applied to an authentication apparatus in which the person to be authenticated performs authentication using his / her face, for example, face authentication or retina authentication.

  As described above, by using the eye image photographing device according to the present invention and the authentication device using the same, it is possible to perform a quick process with a simple configuration for a plurality of persons to be authenticated having a height difference. An eye image capturing device that captures an image including at least the eyes of the person to be authenticated, an authentication device using the same, and the like Useful as.

The figure for demonstrating the function of the authentication apparatus in embodiment of this invention The other figure for demonstrating the function of the authentication apparatus in embodiment of this invention The front view which shows the structure of the tilt part of the authentication apparatus in embodiment of this invention (A) is a side view showing the configuration of the tilt section in the embodiment of the present invention. (B) is a plan view showing the configuration of the tilt section in the embodiment of the present invention. (A) is a figure which shows the structure of the guidance | induction part of the authentication apparatus in embodiment of this invention (b) is a figure for demonstrating the to-be-authenticated person's guidance method by the guidance | induction part of the authentication apparatus in embodiment of this invention. The figure which shows an example of the eye image of the right eye and the eye image of the left eye which were image | photographed with the 2nd imaging | photography part of the authentication apparatus in embodiment of this invention. The block diagram which shows the functional block of the authentication apparatus in embodiment of this invention The figure explaining the coordinate system for demonstrating the function of the distance calculation part of the authentication apparatus in embodiment of this invention, and a height information calculation part The figure which shows an example of the wide-angle image image | photographed with the 1st imaging | photography part for demonstrating the function of the distance calculation part of the authentication apparatus in embodiment of this invention, and a height information calculation part. The flowchart which shows the operation | movement step of the authentication apparatus in embodiment of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Authentication apparatus 2 Distance sensor part 3 1st imaging | photography part 4 2nd imaging | photography part 5 Tilt drive part 6 Tilt part 7 Light source part 8 Axis 9 Drive axis 13 Light source drive part 14 Capture process part 15 Image quality determination part 16 Eye detection Unit 17 Authentication processing unit 18 Iris detection unit 19 Authentication information creation unit 20 Verification unit 21 Storage unit 22 Authentication result determination unit 23 Output unit 30 Person to be authenticated 31 Eye 32 Left eye 33 Right eye 35 Panel unit 40, 41 Eye image 50 Control Unit 51 Distance calculation unit 52 Height information calculation unit 53 Direction prediction unit 54 Distance measurement unit 60 Wall surface unit 65 Wide angle image

Claims (13)

A first photographing unit for photographing the person to be authenticated;
A second imaging unit capable of rotating at least in the height direction of the person to be authenticated;
A distance measuring unit for measuring the distance to the person to be authenticated;
Position information indicating the eye height of the person to be authenticated is calculated from the distance to the person to be authenticated measured by the distance measuring unit and the image of the person to be authenticated photographed by the first photographing unit. An eye position information calculation unit;
When the person to be authenticated approaches from the position information of the eye of the person to be authenticated calculated by the eye position information calculation unit, the eye of the person to be authenticated is positioned at the focal position of the second imaging unit. A direction predicting unit that predicts a direction in which the second photographing unit should be directed;
A drive unit for directing the second imaging unit in a direction to be directed to the second imaging unit predicted by the direction prediction unit;
The second image capturing unit captures an image including at least an eye of the person to be authenticated. The first photographing unit is a wide-angle camera;
The eye image capturing apparatus according to claim 1, wherein the second image capturing unit is a telephoto camera that captures an image with a narrower angle of view than the first image capturing unit. The distance measuring unit detects distance information between both eyes in the image of the person to be authenticated photographed by the first imaging unit, and measures the distance to the person to be authenticated based on the distance information. The eye image photographing device according to claim 1 or 2, wherein The distance measurement unit includes a distance measurement sensor unit, and the distance measurement unit detects the distance information between both eyes in the image of the person to be authenticated photographed by the first imaging unit. The eye image photographing device according to any one of claims 1 to 3, wherein a distance to the person to be authenticated is measured based on an output from a distance sensor unit. An image quality determination unit for determining an image quality of an image captured by the second imaging unit;
The second imaging unit repeatedly performs imaging of an image including at least eyes of the person to be authenticated, and outputs an image determined to have good image quality by the image quality determination unit. Item 5. The eye image capturing device according to any one of Items 4 to 4. The image quality determination unit includes a focus degree calculation unit that calculates a focus degree of an image captured by the second photographing unit,
The second imaging unit repeatedly captures an image including at least the eye of the person to be authenticated, and the image quality determination unit has a degree of focus calculated by the focus level calculation unit higher than a predetermined threshold value. The eye image capturing device according to claim 5, wherein an image is output. An eye detection unit that determines whether an eye is captured in the image captured by the second imaging unit;
The second imaging unit repeatedly captures an image including at least the eye of the person to be authenticated, and outputs an image determined by the eye detection unit to determine that an eye has been captured. The eye image photographing device according to any one of claims 1 to 6. Even if the second imaging unit repeatedly performs imaging, if the image determined that the eye is captured by the eye detection unit cannot be obtained, the second imaging is performed with respect to the driving unit. The eye image capturing device according to claim 7, further comprising a control unit that instructs to move the direction of the unit within a predetermined range. 9. The apparatus according to claim 1, further comprising a guide unit that guides the person to be authenticated to place an eye position at a focal position of the second imaging unit. The eye image photographing device described in 1. The eye image capturing device according to claim 9, wherein the guide unit includes a mirror unit that reflects the eye of the person to be authenticated. 11. The eye according to claim 10, wherein the guide unit includes a mark unit that guides the person to be authenticated such that both eyes of the person to be authenticated are arranged in a frame of the mirror part. Image shooting device. An eye image capturing device according to any one of claims 1 to 11,
An authentication information creating unit that creates predetermined authentication information from an image including at least the eye of the person to be authenticated photographed by the second photographing unit;
A collation unit for comparing and collating pre-registered registration authentication information with the authentication information created by the authentication information creation unit;
If it is determined that the registered authentication information matches the authentication information created by the authentication information creation unit as a result of the comparison and collation by the collation unit, the person to be authenticated is authenticated as a pre-registered person An authentication apparatus comprising: an authentication unit that performs the authentication. The authentication information creating unit creates authentication information from an image of an iris part of the eye by a predetermined method from an image including at least the eye of the person to be authenticated,
13. The authentication apparatus according to claim 12, wherein the registration authentication information is information created by the predetermined method from an image of an iris portion of a person's eye registered in advance.

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