JP5299632B2 - Personal authentication device, program and recording medium - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To enable a vein pattern of a requested area of a finger to be imaged without fail and to realize downsizing and slimming down of a device without having a guide for regulating a position of the finger in the personal authentication device using the vein pattern of the finger. <P>SOLUTION: By a lens array based imaging part 101, the lens array based image of the finger is input. A position determination part 102 determines whether the position correction for the finger is required and how the position correction is made, based on an outline of the finger contained in the single lens based image chosen from among the lens array based images. In response to the determination result of the position determination part 102, a position correction part 103 allows a position correction guide mechanism 105 to guide a movement of finger by a user for the position correction or allows a position correction movement device 106 to move the lens array based imaging part 101 for the position correction. <P>COPYRIGHT: (C)2011,JPO&amp;INPIT

Description

  The present invention relates to a personal authentication technique using biometric information such as a vein pattern such as a finger.

  There is a growing interest in security when contacting confidential information such as the use of information terminals such as computers and mobile phones, and access to buildings. Authentication and usage using a magnetic stripe embedded in a card, a password stored in an IC chip, or a password stored by a user as a means of authenticating whether or not the person is permitted to access information Biometric authentication using the physical characteristics of the person. Cards can be lost, and passwords can be forgotten by users or leaked to others. Biometric authentication has already been known to have the advantage that there is no risk of such loss or forgetting and it is difficult for others to imitate.

  Conventionally, in a personal authentication device that uses a finger or palm vein pattern as biometric information, a technique has been generally adopted in which a vein pattern is imaged in a state where the position of the finger or palm is regulated by a guide unit (for example, Patent Documents). 2). In this way, the position of the living body part is regulated because the accuracy of the authentication process deteriorates or the error occurs if the relative positional relationship between the finger or palm that contains the vein and the camera is not the same at the time of registration and authentication. This is because inconveniences such as the occurrence of a problem occur. However, it is inevitable that the living body comes into contact with the guide portion, and there is a problem that the entire apparatus is enlarged by providing the guide portion. In a situation where an unspecified number of people use it, it is not desirable to bring the living body into contact for reasons of hygiene. As information terminals represented by mobile phones and laptop computers are becoming smaller and thinner, there is a problem that hinders the installation of personal authentication devices in these information terminals if the device size is large.

  Patent Document 1 discloses a personal authentication device for the purpose of performing authentication with high accuracy without fixing a living body. This personal authentication device includes a registration unit and an authentication unit. For example, the registration unit acquires a three-dimensional biological information by imaging a finger and transmits the information to which the necessary information is added to the authentication unit. The authentication unit corrects the three-dimensional biometric information received from the registration unit to match the registrant's finger position, tilt, joint bending, etc., and the corrected three-dimensional biometric information and the authentication unit Personal authentication is performed using biometric information acquired by imaging. However, on the authentication means side, it is necessary to provide a position measuring means that transmits light or ultrasonic waves to the finger and measures the reflection time thereof, a means for complex correction processing of 3D biological information, etc. In addition, since it is necessary to provide a means for acquiring three-dimensional biological information using X-ray measurement, magnetic resonance measurement, light measurement, ultrasonic measurement, etc. on the registration means side, the authentication apparatus becomes large and portable information There are problems that it is difficult to mount on a terminal or the like, and that it is difficult to reduce the cost of the apparatus.

  The present invention has been made in view of the above-described problems in a personal authentication device that uses a vein pattern of a living body part including a vein such as a finger or a palm, and a guide member for regulating the position of the living body part. It is an object of the present invention to provide a personal authentication device that can perform highly accurate personal authentication without being equipped with, and that can be easily reduced in size, thickness, and cost.

The personal authentication device according to the present invention captures a lens array in which a plurality of lenses are arranged on a substantially flat surface and a user's biological part held over the lens array as a compound eye image that is a set of a plurality of single-eye images. Compound eye imaging means comprising an element;
Contour extraction processing for extracting a contour of a living body part is performed using a single-eye image set for position determination in a compound eye image captured by the compound eye imaging means, and the compound eye imaging is performed based on a result of the contour extraction processing. Position determining means for performing position determination for determining whether or not the position of the biological part relative to the means needs to be corrected and a method for correcting the necessary position;
According to the method for correcting the necessary position determined by the position determination means, the means for guiding the user is guided to the user for movement for correcting the position of the living body part, or the compound eye Position correcting means for moving the compound eye imaging means for correcting the position of the living body part by means for moving the imaging means;
An authentication processing unit that performs an authentication process using a single-eye image set for authentication in a compound eye image captured by the compound eye imaging unit when it is determined by the position determining unit that correction of the position of the living body part is unnecessary; With
There are a plurality of combinations of single-eye images set for the position determination and single-eye images set for the authentication,
The position determination means uses, as a position determination single-eye image, a single eye image set for position determination based on a result of contour extraction processing of a single-eye image set for position determination for each pair. Determine the position based on the result of the contour extraction processing of the position determination single-eye image,
The main feature of the authentication processing means is that the authentication processing is performed using a single eye image set for authentication in the same set as the single eye image for position determination determined by the position determination means.

In the personal authentication device of the present invention, it is determined whether or not the position of the biological part relative to the compound eye imaging means needs to be corrected and a necessary position correction method. In this position determination, when position correction is necessary and the correction method is determined, the movement of the living body part for position correction is guided to the user accordingly, or the position of the living body part The position of the living body part is corrected by moving the compound eye imaging means for correction. As a result of such position correction, when it is determined that position correction is not necessary for the input compound eye image, authentication processing using the compound eye image is performed. If the position determination criterion is set so that it is determined that correction of the position of the living body part is not necessary when a desired region of the living body part is imaged, the position of the living body part Even if a guide member for regulating the position is not provided, a compound eye image obtained by imaging a desired region of the living body part can be input, and accurate authentication processing using the compound eye image can be performed. Thus, the personal authentication device of the present invention does not need to include a guide member or the like for regulating the position of the living body part. The compound eye imaging means using the lens array has a structure that can be easily reduced in size and thickness. Therefore, the personal authentication device of the present invention can be easily reduced in size and thickness as a whole. In addition, the personal authentication device of the present invention does not require complicated and expensive measuring means or the like as in the device of Patent Document 1, and can be realized at low cost.

In addition, in order to input a subject image having a resolution necessary for performing the authentication process with high accuracy by the compound eye imaging unit, it is necessary to bring the living body part that is the subject close to the lens array of the compound eye imaging unit. When the living body part is brought closer, the region of the living body part captured in one single-eye image is limited. For example, if a finger is used as a living body part and its vein pattern is imaged and used for authentication, a fingertip suitable for position determination and a vein pattern part suitable for authentication are simultaneously imaged in a single eye image. Is not easy. In the personal authentication device of the present invention, since individual eye images in a compound eye image are used for position determination and authentication processing, a fingertip suitable for position determination and a vein pattern part suitable for authentication are simultaneously imaged. Is easy.

Furthermore, in the personal authentication device of the present invention, there are a plurality of combinations of the single-eye image set for position determination and the single-eye image set for authentication. Opportunities to capture a vein pattern suitable for authentication on a single image increase. Then, based on the result of the contour extraction processing of the single-eye image set for position determination, the single-eye image set for one set of position determination is determined as the single-eye image for position determination, and the position determination Since the position determination is performed based on the result of the contour extraction process for the single eye image, and the single image set for authentication in the same set as the single image for position determination is used for the authentication process, the entire process Speeding up and reducing the burden on the user.

It is a block diagram for demonstrating the functional structure of the personal authentication apparatus which concerns on Embodiment 1. FIG. 3 is a flowchart illustrating an overall processing flow of the personal authentication device according to the first embodiment. 3 is a schematic cross-sectional view of a compound eye imaging unit in the personal authentication device according to Embodiment 1. FIG. It is a schematic diagram which shows an example of a compound eye image in case a finger exists in a suitable position. It is a schematic diagram which shows the outline extraction result of the single-eye image for position determination. It is the figure which plotted the position coordinate of the pixel which comprises an outline on xy plane. It is a schematic diagram which shows an example of a compound eye image in case finger position correction is required. It is a figure which shows the specific example of the position determination about a x direction. It is a figure which shows the specific example of the position determination about a x direction. It is a figure which shows the specific example of the position determination about ay direction. It is a figure which shows the specific example of the position determination about ay direction. It is a figure which shows the specific example of the position determination about az direction. It is a flowchart for demonstrating the processing flow of three-dimensional position correction. It is a schematic diagram for demonstrating the form of a position correction guide means and a position correction movement means. FIG. 10 is a schematic diagram illustrating an example of a compound eye image input by a compound eye imaging unit of the personal authentication device according to the second embodiment. 10 is a flowchart for explaining an overall processing flow of the personal authentication device according to the second embodiment. It is a flowchart for demonstrating the process which determines the single image for position determination, and the single image for authentication. It is a block diagram for demonstrating the functional structure of the personal authentication apparatus which concerns on Embodiment 3. FIG. It is a schematic sectional drawing of the compound eye imaging part in the personal authentication device concerning Embodiment 3. 10 is a flowchart for explaining an overall processing flow of the personal authentication device according to the third embodiment. It is a schematic diagram for demonstrating the compound eye image input by the compound eye imaging part of the personal authentication apparatus which concerns on Embodiment 3. FIG. It is explanatory drawing of the system which connected the personal authentication apparatus of this invention to the information equipment as an authentication apparatus.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the embodiment described below, the vein pattern inside the finger is used as the biometric information for personal authentication. However, the vein pattern of the other living body part (palm etc.) that contains the vein is used similarly. Of course, a form of performing personal authentication is also possible.

[Embodiment 1]
FIG. 1 is a block diagram for explaining a functional configuration of the personal authentication device according to the first embodiment of the present invention. The personal authentication apparatus includes a compound eye imaging unit 101, a subject position determination unit 102, a position correction unit 103, an authentication processing unit 104, and a registration processing unit 107. Further, as a means for correcting the subject position, a position correction guide unit 105 is provided. Alternatively, position correction moving means 106 is provided. Note that an embodiment including both the position correction guide means 105 and the position correction moving means 106 as means for correcting the subject position is also included in the present embodiment.

  The compound eye imaging unit 101 has a living body part (here, a person who receives authentication or a person who registers a vein pattern) held over the lens array via a lens array in which a plurality of lenses are arranged on a substantially plane. In this case, the image is captured by the image sensor as a compound eye image, and the captured compound eye image is input as digital image data. Specific examples thereof will be described later.

  In order to perform personal authentication using a finger vein pattern with high accuracy, it is necessary to image substantially the same region of the finger during authentication and during registration. However, when a guide part for restricting the position of the finger is not provided as in the prior art, the positional relationship between the compound-eye imaging device 101 and the finger is unstable, and the position of the finger region to be imaged is not stable. Therefore, the personal authentication device of the present invention includes a mechanism for correcting the relative position of the subject with respect to the compound-eye imaging unit 101 so that a desired region of the finger that is the subject is imaged. Since this mechanism is provided, it is possible to image almost the same region of the finger during authentication and registration without providing a guide part for regulating the position of the finger as in the prior art. Note that the personal authentication device according to the present embodiment can perform both an authentication operation for performing an authentication process for comparing a captured vein pattern with a registered pattern and a registration operation for registering the captured vein pattern as a registered pattern. Even in the case where the registration operation is performed separately, high-accuracy personal authentication is possible if images are taken of substantially the same region of the finger.

  Specifically, the above-described mechanism for subject position correction is realized by the subject position determination unit 102, the position correction unit 103, the position correction guide unit 105, and / or the position correction moving unit 106.

  The subject position determination unit 102 pays attention to the contour of the subject captured in the single-eye image for subject position determination in the compound eye image input by the compound eye imaging unit 101, and the relative position of the subject with respect to the compound eye imaging unit 101 It is a means for determining whether or not it is necessary to correct and what kind of position correction is necessary (necessary position correction method). A specific example of this position determination will be described later.

  The position correction unit 103 is a unit that realizes necessary finger position correction by operating the position correction guide unit 105 or the position correction moving unit 106 according to the position correction method determined by the subject position determination unit 102. is there. The position correction guidance means 105 is a means for guiding the movement of a finger for position correction to the user through vision, hearing, or the like. The position correction moving means 106 is a means for moving at least the compound eye imaging unit 101 for position correction.

  The authentication processing unit 104 is a unit that performs authentication processing using the compound eye image input by the compound eye imaging unit 101. More specifically, the authentication processing unit 104 includes a recognition single-eye image (user's vein pattern image) in the input compound eye image, and a registration pattern (registered user's veins) stored in the registration processing unit 107. Pattern image) and determining whether or not the user is a registered user based on the similarity or difference. As a matching method, a known pattern matching may be used, or a known feature base matching for obtaining a correspondence between pattern feature points may be used.

  The registration processing unit 107 is a means for storing a recognition single-eye image (vein pattern image) in the compound-eye image input by the compound-eye imaging unit 101 as a registration pattern. When feature-based matching is used in the authentication processing unit 104, the registration processing unit 107 may extract the feature points of the vein pattern and store the extracted feature point data as a registration pattern.

  FIG. 2 shows an overall processing flow of the personal authentication apparatus according to the present embodiment. The compound eye imaging unit 101 captures a subject (here, the user's finger) and inputs the compound eye image (step 201). The subject position determination unit 102 extracts a preset single image for subject position determination from the input compound eye image (step 202), and performs contour extraction processing for extracting the contour of the subject from the single eye image. Is performed (step 203), and the position of the subject is determined based on the result of the contour extraction process (step 204). If it is determined in this position determination that position correction is not necessary (position correction completion) (step 205, YES), and an authentication operation is selected, a preset authentication single eye in the input compound eye image When the authentication processing using the image is performed in the authentication processing unit 104 and the registration operation is selected, the registration processing unit 107 performs processing for registering the same single-eye image as a registration pattern (step 206). When it is determined in step 204 that position correction is necessary (step 205, NO), the position correction unit 103 positions the movement of the finger for position correction according to the position correction method determined by the position determination unit 102. Guidance is made by the repair guidance means 105 or the movement of the compound eye imaging unit 101 for position correction is performed by the position correction movement means 106 (step 207), and the processing returns to step 201.

  FIG. 3 is a schematic cross-sectional view showing an example of the compound eye imaging unit 101. In FIG. 3, 11 is a lens array, 12 is a light shielding member, 13 is an image sensor, and 14 is a cover glass.

  In this embodiment, the lens array 11 is an array of two lenses 11a and 11b, and an optical image of the subject 1 (finger) held over the lens array 11 is formed on the image plane by each lens. The arrangement direction of the lenses 11 a and 11 b is a direction corresponding to the axial direction of the finger that is the subject 1. The light shielding member 12 is for preventing crosstalk on the imaging surface of the imaging element 13 of light that has passed through the lenses 11a and 11b of the lens array 11, and suppressing noise such as ghost and flare. The imaging device 13 receives an optical image (single-eye image) of the subject 1 formed by the lenses 11 a and 11 b of the lens array 11, converts it into an electrical signal, and converts a compound eye image composed of two single-eye images. Specifically, a CMOS image sensor or a CCD image sensor in which a large number of photoelectric elements 13a are two-dimensionally arranged is used. The image sensor 13 has a built-in circuit that adjusts the gain of the electrical signal (analog signal) converted by the photoelectric element 13a and converts the analog signal into a digital signal, and outputs a compound eye image as digital data. . The cover glass 14 is for protecting the lens array 11.

  In FIG. 3, the lenses 11 a and 11 b of the lens array 11 are shown as plano-convex lenses convex toward the image sensor 13, but they can also be double-sided convex lenses or plano-convex lenses convex toward the subject side. However, when a plano-convex lens convex toward the image sensor 13 is used, better imaging performance can be obtained over a wider angle of view than when a plano-convex lens convex toward the subject is used. Further, when the plano-convex lens is used, the manufacturing cost of the lens array 11 can be reduced as compared with the case where the double-side convex lens is used.

  Next, the subject position determination unit 102 and the position correction unit 103 will be further described.

  FIG. 4 schematically illustrates an example of a compound eye image captured by the compound eye image unit 101 illustrated in FIG. 3. In FIG. 4, 21 is a single-eye image corresponding to the lens 11b, 22 is a single-eye image corresponding to the lens 11a, and the outline of the finger is represented by a thick line in each single-eye image, and the vein pattern is a light line. It is represented. Here, the single-eye image 21 is a single-eye image set for authentication, and the single-eye image 22 is a single-eye image set for subject position determination. Since each single-eye image is an image that is formed by inverting the image vertically and horizontally through the lenses of the lens array, the finger that is the subject does not appear to be continuous in the compound-eye image. Note that the example of FIG. 4 is a case where the desired subject position is such that a desired region of the finger that is the subject is imaged, and the vein of the finger part suitable for vein authentication is included in the individual image for authentication 21. A pattern is imaged.

  The subject position determination unit 102 performs contour extraction processing (step 203 in FIG. 2) for extracting the contour of the finger from the single image for position determination as preprocessing for position determination. In the case of the single eye image 22 shown in FIG. 4, the result of the contour extraction process is as shown in FIG. There is a sharp change in the pixel value in the contour portion, and contour extraction can be performed using this. For example, contour extraction by general filtering using a known Sobel filter or the like is possible.

  FIG. 6 is a diagram for explaining the position determination using the result of the contour extraction process, that is, the extracted contour as shown in FIG. The extracted contour is output as a set of position coordinates (x, y) of the pixels constituting the contour. When these are plotted on the xy plane (here, the lower left corner of the position determination single-eye image 22 is taken as the origin), FIG. 6 is obtained. Whether or not the x coordinate when the contour coordinate moves from y1 to y2 is continuous can be used as a criterion for determining whether or not the fingertip is included in the single eye image for subject position determination. If the contour of the fingertip is included, it can be determined that the position correction in the x direction is not necessary, and if the contour of the fingertip is not included, it can be determined that the position correction in the x direction is necessary. . Therefore, when a compound eye image as shown in FIG. 4 is captured, it is determined that position correction is not necessary. By using such a determination criterion, it is possible to image almost the same part of the finger. And it can respond in the design stage of the compound eye imaging part 101 so that the site | part may become a vein pattern site | part suitable for an authentication process.

  FIG. 7 shows an example of a compound eye image captured at a subject position such that the fingertip is not included in the single-eye image 22 for subject position determination. When the subject position determination described in relation to FIG. 6 is performed on the single-eye image 22 in such a compound eye image, the finger contour is included but the fingertip contour is not included. When moving to y2, a location where the x coordinate becomes discontinuous occurs, and it is determined that the position correction in the x direction is necessary.

  A specific example of position determination in the x direction (finger axial direction) as described above is shown in FIG. In FIG. 8, Case 0 is a case where there is no finger outline in the position determination single-eye image, and it is determined that position correction for moving the finger in the distal direction is necessary. Case 1 is a case where the position determination single-eye image has a finger outline but is not continuous (there is a portion where the x coordinate is discontinuous when moving from y1 to y2), and moves the finger in the base direction. It is determined that position correction is necessary. Case 2 is a case where there is a finger outline and is continuous (there are no locations where the x coordinate is discontinuous when moving from y1 to y2), and it is determined that position correction is not necessary.

  Further, not only whether or not the contour of the fingertip is included as in the example of FIG. 8, but by providing a predetermined range in the coordinates of the contour of the fingertip, the accuracy of position correction is improved, and the accuracy of authentication is high. Can be achieved. For example, in order to adjust the position of the fingertip to a desired position more accurately, the position correction may be performed until the x-coordinate x1 of the fingertip falls within a predetermined range [Xa, Xb]. It is also possible to determine that no position correction is required only when xa is equal to only one coordinate value X without setting a width in the predetermined range, that is, Xa = Xb = X. In this way, high-accuracy position correction is possible so that a desired vein pattern site is imaged.

  FIG. 9 shows a specific example of position determination in the x direction using the predetermined range as described above. In FIG. 9, Case 0 is a case where there is no contour of the finger in the position determination single-eye image, and it is determined that position correction for moving the finger in the distal direction is necessary. Case 1 is a case where the position determination single-eye image has a finger outline but is not continuous (there is a portion where the x coordinate is discontinuous when moving from y1 to y2), and moves the finger in the base direction. It is determined that position correction is necessary. Case2 is a case where the finger has a contour and is continuous (there is no part where the x coordinate becomes discontinuous when moving from y1 to y2), but x1 is not within a predetermined range, and x1 is predetermined. It is determined that position correction for moving the finger in the direction of entering the range is necessary. Case 3 is a case where the finger has a contour and is continuous (there is no part where the x coordinate is discontinuous when moving from y1 to y2), and x1 is within a predetermined range. It is determined that it is not necessary.

  Also in the y direction, the same position determination and position correction based on the contour extracted by the contour extraction process can be performed.

  First, FIG. 10 shows a specific example of position determination in the y direction focusing on the presence or absence of the contour of the finger side portion. In FIG. 10, Case 0 is a case where there is no finger contour in the position determination single-eye image, and it is determined that position correction is required to move the finger in the y direction so that the contour is imaged. Case 1 is a case where the position determination single-eye image has a finger outline, but there is no outline on one side of the finger side part, and the finger is moved in the y direction in a direction in which the outlines on both sides of the finger side part are imaged. It is determined that position correction is necessary. Case 2 is a case where there is a contour of the finger and there are contours on both sides of the finger side portion, and it is determined that position correction is not necessary.

  Further, if position determination in the y direction is performed by checking whether or not the y-coordinates y1 and y2 (FIG. 6) of the contour of the finger side are within a predetermined range, position correction with higher accuracy is possible. is there. A specific example of such position determination in the y direction is shown in FIG.

  In FIG. 11, Case 0 is a case where there is no finger contour in the position determination single-eye image, and it is determined that position correction is required to move the finger in the y direction so that the contour is imaged. Case 1 is a case where there is a contour of a finger but there is no contour on one side of the finger side, and it is determined that position correction is required to move the finger in the y direction in the direction in which the contours on both sides of the finger side are imaged. The Case 2 is a case where there is a contour of the finger and there are contours on both sides of the finger side, but the y-coordinates y1 and y2 of these contours are not within the predetermined range, and the finger is oriented so that y1 and y2 fall within the predetermined range. It is determined that position correction for moving the image in the y direction is necessary. Case 3 is a case where there is a finger contour, there are contours on both sides of the finger side, and y1 and y2 are in a predetermined range, and it is determined that position correction in the y direction is not necessary.

  In addition to the above-described position correction in the plane, the thickness of the finger, that is, the difference in y-coordinate of the contour of the finger side (y2-y1) is used for the subject distance direction (hereinafter referred to as the z direction). Position determination is possible. Since the subject distance that can capture a vein pattern suitable for vein authentication is known at the time of design, an appropriate range of finger thickness on a single-eye image at that time is estimated, and based on this, (y2-y1) The predetermined range can be set. A specific example of such position determination in the z direction is shown in FIG. However, since the values of y1 and y2 are used for the determination, it is assumed that both the contours of the finger side portions are imaged.

  In FIG. 12, Case 0 is a case where (y2-y1) is not within the predetermined range, and it is determined that position correction is required to move the finger in the z direction so that (y2-y1) falls within the predetermined range. Case 1 is a case where (y2−y1) is in a predetermined range, and it is determined that position correction in the z direction is not necessary.

  The specific example of the position determination for each xyz direction has been described above. Then, position determination and position correction only in the x direction, position determination and position correction only in the y direction, and position determination in the x and y directions are combined to perform two-dimensional position correction in the x and y directions, x, y, and z It is possible to perform three-dimensional position correction in the x, y, and z directions by combining the position determination in the direction.

  First, the operation when position determination and position correction are performed only in the x direction will be described.

  When the position determination method of FIG. 8 is used, position correction is performed until the determination result of Case 2 of FIG. 8 is obtained by the position determination by the subject position determination unit 102 (step 204) (NO in step 205 of FIG. 2). The flow of processing is to take an image and perform position determination again. When the result of the position determination is Case 0 in FIG. 8, in step 207 in FIG. 2, the position correction unit 103 guides the user to move the finger to the distal end side by the position correction guide unit 105 or compound eye imaging. The compound eye imaging unit 101 is moved in the opposite direction, that is, toward the base of the finger by the position correction moving unit 106 so that the finger is moved relative to the unit 101 toward the tip side. When the result of the position determination is Case 1 in FIG. 8, in step 207 in FIG. 2, the position correction unit 103 guides the user to move the finger toward the root side by the position correction guide unit 105, or compound eye imaging. The compound eye imaging unit 101 is moved in the opposite direction, that is, toward the tip of the finger so that the finger is moved toward the base side relative to the unit 101.

  When the position determination method of FIG. 9 is used, until the determination result of Case 3 of FIG. 9 is obtained by the position determination by the subject position determination unit 102 (NO in step 205 of FIG. 2), the position is corrected and imaged again. The processing flow is to perform position determination. When the result of the position determination is Case 0 in FIG. 9, in step 207 in FIG. 2, the position correction unit 103 guides the user to move the finger to the tip side by the position correction guide unit 105, or compound eye imaging The compound eye imaging unit 101 is moved in the opposite direction, that is, toward the base of the finger by the position correction moving means 106 so that the finger is moved toward the tip side relative to the unit 101. When the result of the position determination is Case 1 in FIG. 9, in step 207 in FIG. 2, the position correction unit 103 guides the user to move the finger toward the root side by the position correction guide unit 105 or compound eye imaging. The compound eye imaging unit 101 is moved in the opposite direction, that is, toward the tip of the finger so that the finger is moved toward the base side relative to the unit 101. When the result of the position determination is Case 2 in FIG. 9, in step 207 in FIG. 2, when x1 is smaller than the minimum value in the predetermined range, the position correction guide unit 105 puts a finger on the user side to the root side. The compound eye imaging unit 101 is moved in the opposite direction, that is, toward the distal end side of the finger by the position correction moving means 106 so that the finger is moved relative to the compound eye imaging unit 101 and moved toward the root side. When x1 exceeds the maximum value in the predetermined range, the position correction unit 103 guides the user to move the finger to the distal end side by the position correction guide unit 105 or is relative to the compound eye imaging unit 101. The compound eye imaging unit 101 is moved in the opposite direction, that is, toward the base of the finger by the position correction moving means 106 so that the finger is moved to the tip side.

  Next, an operation when position determination and position correction are performed only in the y direction will be described.

  When the determination method of FIG. 10 is used, until the determination result of Case 2 of FIG. 10 is obtained by the position determination (step 204) by the subject position determination unit 102 (step 205 of FIG. 2, NO), the position is corrected and imaged. Then, the flow of processing for determining the position again is performed. When the result of the position determination is Case 0 in FIG. 10, in step 207 in FIG. 2, the position correction unit 103 causes the position correction guide unit 105 to move the finger to the user, for example, directly above the lens on the lens array. The compound eye imaging unit 101 is moved by the position correction moving means 106 so as to scan in the y direction by a predetermined width, for example. When the result of the position determination is Case 1 in FIG. 10, in step 207 in FIG. 2, the position correction unit 103 causes the position correction guide unit 105 to place the finger in the direction in which the contours on both sides of the finger side are imaged. The compound eye imaging unit 101 is moved by the position correction moving means 106 so as to be guided to move in the y direction or to move the finger relative to the compound eye imaging unit 101 in that direction.

  When the determination method of FIG. 11 is used, until the determination result of Case 3 of FIG. 11 is obtained by the position determination (step 204) by the subject position determination unit 102 (step 205 of FIG. 2, NO), the position is corrected and imaged. Then, the flow of processing for determining the position again is performed. When the result of the position determination is Case 0 in FIG. 11, in step 207 in FIG. 2, the position correction unit 103 causes the position correction guide unit 105 to move the finger to the user, for example, directly above the lens on the lens array. The compound eye imaging unit 101 is moved by the position correction moving means 106 so as to scan in the y direction by a predetermined width, for example. When the result of the position determination is Case 1 in FIG. 11, in step 207 in FIG. 2, the position correction unit 103 causes the position correction guide unit 105 to place the finger in the direction in which the contours on both sides of the finger side are imaged. The compound eye imaging unit 101 is moved in the opposite direction by the position correction moving means 106 so as to be guided to move in the y direction or to move the finger relative to the compound eye imaging unit 101 in that direction. When the result of the position determination is Case 2, in step 207 of FIG. 2, the position correction unit 103 causes the position correction guide unit 105 to place the y coordinates y1 and y2 of the contours on both sides of the finger side part within a predetermined range with respect to the user. The compound eye imaging unit 101 is moved in the opposite direction by the position correction moving unit 106 so that the finger is guided to move in the y direction in the direction, or the finger is moved relative to the compound eye imaging unit 101 in that direction.

  An operation in the case where two-dimensional position correction is performed by combining the position determination in the x and y directions and the position correction described above will be described. For example, it is assumed that the position correction in the y direction is performed, and the position correction in the x direction is performed after the correction.

  If the position determination method of FIG. 10 or FIG. 11 is used in the y direction, the result of the position determination in step 204 of FIG. 2 is Case 0 or Case 1 of FIG. 10, or Case 0, Case 1 or Case 2 of FIG. If so, a position correcting operation corresponding to the determination result is performed in step 207 of FIG.

  If the determination result of Case 2 in FIG. 10 or Case 3 in FIG. 11 is obtained in step 204, the position correction in the y direction is terminated, and the process proceeds to position determination in the x direction. If the position determination method of FIG. 8 or FIG. 9 is used in the x direction, if the determination result is Case 0 or Case 1 of FIG. 8 or Case 0, Case 1 or Case 2 of FIG. 9, it corresponds to the determination result in step 207 of FIG. The position correction operation is performed. When the determination result of Case 2 in FIG. 8 or Case 3 in FIG. 9 is obtained in Step 204, the position correction is completed (Step 205, YES).

  It is possible to perform three-dimensional position correction by combining position correction in the x, y, and z directions. Such three-dimensional position correction can be executed by a processing flow as shown in FIG. 13, for example. Of course, a different processing flow can be used.

  In FIG. 13, in step 210, for example, the position determination in the y direction by the position determination method in FIG. 10 and the position correction in the y direction according to the determination result are performed until the determination result of Case 2 in FIG. This is repeated until both the contours on the side of the finger are imaged in the single image for position determination. Then, when the determination result of Case 2 in FIG.

  In step 220, the position determination in the z direction by the position determination method of FIG. 12 and the z direction position correction according to the determination result are performed until the determination result of Case 2 of FIG. 12 is obtained, that is, (y2-y1) Repeat until is within the predetermined range. Then, at the stage where the determination result of Case 2 in FIG. 12 is obtained, it is assumed that the position correction in the z direction has been completed, and the process proceeds to step 230.

  In step 230, for example, the position determination in the y direction by the position determination method of FIG. 11 and the y direction position correction according to the determination result are performed until the determination result of Case 3 of FIG. 11 is obtained, that is, y1 and y2 are predetermined. Repeat until in range. Then, when the determination result of Case 3 in FIG. 11 is obtained, it is assumed that the position correction in the y direction has been completed, and the process proceeds to step 240.

  In step 240, for example, position determination in the x direction by the position determination method in FIG. 9 and position correction in the x direction according to the determination result are performed until the determination result of Case 3 in FIG. 9 is obtained, that is, x1 is predetermined. Repeat yet still in the range. When the determination result of Case 3 in FIG. 9 is obtained, the position correction is completed (the determination in step 205 in FIG. 2 is YES).

  Naturally, any of the above-described embodiments for correcting the position in the x direction, the y direction, the xy direction, and the xyz direction is included in the present embodiment.

  The reason or advantage of using separate single-eye images for subject position determination based on the above-described finger contour and authentication processing is as follows. In order to obtain the resolution of the vein pattern necessary for performing the authentication process with high accuracy, it is necessary to bring the compound eye imaging unit close to the finger as the subject. When the subject is brought close, the subject area captured in one single-eye image is limited, and it is difficult to simultaneously capture the fingertip and the vein pattern portion suitable for authentication in one single-eye image. Therefore, the contour of the fingertip is captured with a single-eye image different from the single-eye image used for the authentication process, and is used for subject position determination. In this way, the fingertip suitable for position determination and suitable for authentication are used. It is possible to simultaneously image various vein pattern portions.

  14A to 14C are schematic diagrams for explaining the mode of the position correction guide means 105, and FIG. 14D is a schematic diagram for explaining the mode of the position correction moving means 106. is there.

  In FIG. 14A, reference numeral 30 denotes a main unit including at least the compound-eye imaging unit 101, and a guide unit 31 serving as a position correction guide unit 105 is provided separately or integrally with the main unit 30. This guide unit 31 is provided with arrow marks 32 in the x and y directions on the surface on which a finger as a subject is held, and a light source (not shown) such as one or a plurality of LEDs corresponding to the arrow marks. ) And its drive circuit. The position correction unit 103 turns on the light source corresponding to the arrow in the direction and direction in which the finger is to be moved, and guides the user to move the finger for position correction by lighting the arrow. That is, in this example, guidance is provided to the user through vision. It is also possible to provide the same arrow mark for position correction in the z direction, etc., and illuminate it to guide the position correction in the z direction, but all the arrow marks in the x and y directions are simultaneously displayed. It is also possible to guide the position correction in the z direction by a method of illuminating or a method of providing a plurality of color light sources for each arrow mark in the x and y directions and switching the color of the light source to be lit.

  In FIG. 14B, a guide unit 33 as the position correction guide means 105 is provided separately or integrally with the main body unit 30 including at least the compound eye imaging unit 101. The guide unit 33 includes a speaker 34 and a driving circuit (not shown). The position correction guide unit 103 generates a guidance voice for position correction from the speaker 32 and causes the user to correct the position of the finger. That is, in this example, guidance is given to the user through hearing.

  It should be noted that a position correction guide means that combines the visual guidance method as shown in FIG. 14A and the auditory guidance method as shown in FIG. 14B can be easily realized. By using such position correction guidance means, it is possible to reliably perform position correction guidance even for persons with visual or auditory impairments.

  In FIG. 14C, a display device 35 such as a liquid crystal display independent of the main unit 30 including at least the compound-eye imaging unit 101 is used as the position correction guide unit 105. The position correction unit 103 guides the position correction by displaying, for example, a mark such as an arrow similar to the guide unit 31 of FIG. In the case where the display device 35 is provided with a speaker, it is also possible to take a form using voice guidance together.

  In FIG. 14D, reference numeral 36 denotes a moving mechanism as the position correction moving means 106, which corrects the position by moving the main body unit 30 including the compound eye imaging unit 101 in the xy direction or the xyz direction. Such a moving mechanism 36 can be easily realized by using a driving means such as a known linear actuator.

[Embodiment 2]
A second embodiment of the present invention will be described. The personal authentication device according to the present embodiment has the same block configuration as shown in FIG. 1 as the personal authentication device according to the first embodiment.

  The compound-eye imaging unit 101 is basically configured as shown in FIG. 3 similar to that of the first embodiment. However, the lens array 11 has a larger number of lenses arranged in a two-dimensional array, and imaging is performed. The compound eye image includes at least two single-eye images set for subject position determination and at least two single-eye images set for authentication corresponding to these single-eye images.

  Here, for simplicity of explanation, the lens array 11 of the compound-eye imaging unit 101 has a 4 × 2 array of four lenses, and four lenses corresponding to the four lenses as shown in FIG. It is assumed that a compound eye image that is a set of eye images 21, 22, 23, and 24 is captured. The single-eye images 22 and 24 are set for subject position determination, and the single-eye image images 21 and 23 are set for authentication, and are associated with the single-eye images 22 and 24, respectively. . That is, in this example, there are two combinations of the single eye image set for position determination and the single eye image set for authentication in the input compound eye image.

  FIG. 15 schematically shows a state in which a finger as a subject is positioned immediately above a lens corresponding to the single-eye images 21 and 22 and a vein pattern suitable for authentication is captured in the single-eye image 21. Is shown in As is clear from this, the lenses corresponding to the single-eye images 21 and 22 are in the same positional relationship as the lenses corresponding to the single-eye images 21 and 22 in FIG. These lenses have the same positional relationship.

  FIG. 16 shows an overall processing flow of the personal authentication device according to the present embodiment. The correspondence between the processing steps in FIG. 16 and the processing steps in FIG. 2 is as follows. Step 301 is Step 201, Step 302 is Step 202, Step 303 is Step 303, Step 305 is Step 204, Step 306 is Step 205, Step 307 is Step 206, Step 308 is Step 207, respectively. Corresponding processing step. Note that step 302 is different from step 202 in that a single eye image set for “plurality” position determination is extracted from the input compound eye image. Further, step 303 is different from step 203 in that contour extraction is performed on these “plurality” of single-eye images.

  Step 304 is for stepping a set of single-eye images from a combination of two (two in this case) single-eye images set for position determination and single-eye images set for authentication. This is a processing step for determining as a single eye image for use in the position determination of 305 and the authentication processing in step 307, and is added in the present embodiment. An example of the processing flow of this processing step is shown in FIG.

  In step 310 of FIG. 17, the position determination in the x direction and the y direction is performed for each of the single-eye images 22 and 24 set for position determination. Here, the determination method of FIG. 9 is used for the x direction, and the determination method of FIG. 11 is used for the y direction. If the images are captured in the positional relationship as shown in FIG. 15, the determination result of one single-eye image 22 is Case 3 in FIG. 9 and Case 3 in FIG. 11 (position correction is not required in both the x and y directions). The determination result of the other single-eye image 24 is Case 3 in FIG. 9 and Case 1 in FIG. 11 (position correction is not necessary for the x direction, but position correction is necessary for the y direction).

  In the next step 311, in order to determine the superiority or inferiority of each combination of the single-eye image set for position determination and the single-eye image set for authentication, the single-eye images 22 and 24 in the previous step are determined. The position determination result for is evaluated. As this evaluation method, for example, a method of calculating the sum of the case numbers of the position determination results in the x and y directions of the single-eye images 22 and 24 as an evaluation value and evaluating higher as the evaluation value is larger can be used. . However, it goes without saying that the method is not limited to this.

  In step 312, the single-eye image set for position determination and the single-eye image set for authentication of the set having the larger evaluation value calculated in the previous step are converted into the position determination in step 305 and step 307. Are determined as individual images used in the authentication process. In the case of the imaging conditions as shown in FIG. 15, the single-eye image 22 is determined as a single-eye image for position determination, and the single-eye image 21 is determined as a single-eye image for authentication. When a finger is directly above the lens corresponding to the single-eye images 23 and 24, the single-eye image 24 is used as a single-eye image for position determination, and the single-eye image 23 is used as a single-eye image for authentication. Will be determined.

  As described above, there are a plurality of combinations of single-eye images set for position determination and single-eye images set for authentication, and one set of single-eye images is selected to perform position determination. Since it is used for each authentication process, there are many opportunities to capture a vein pattern suitable for the authentication process, and the entire process can be speeded up and the burden on the user can be reduced.

  When the evaluation values calculated for the two position determination single images in step 311 in FIG. 17 are the same value, either one of the pair of position determination single images and the authentication single image Should be selected.

[Embodiment 3]
Embodiment 3 of the present invention will be described. FIG. 18 is a block diagram for explaining a functional configuration of the personal authentication apparatus according to the present embodiment. Elements corresponding to those in FIG. 1 according to the first embodiment are denoted by the same reference numerals.

  In the present embodiment, the compound eye imaging unit 101 uses a lens array 11 in which a large number of lenses are arranged in a two-dimensional array as shown in FIG.

  The reconstruction processing unit 108 added in the present embodiment performs a process for reconstructing a single image with higher definition using a parallax between single-eye images from a plurality of single-eye images in a compound-eye image. It is.

  The processing contents will be described more specifically. The reconstruction processing unit 108 estimates a parallax (image shift) between single-eye images in a compound-eye image. For this parallax estimation, for example, a well-known pattern matching can be used. That is, a single eye image as a reference is selected from a compound eye image, a part of the reference single eye image is used as a template, and the similarity or difference between the single eye image to be estimated is calculated while moving this template. To do. As the dissimilarity, SSD (sum of squares of pixel value differences) or SAD (sum of absolute values of pixel value differences) can be used. Then, the shift amount that minimizes the calculated difference can be obtained as the parallax.

  The reconstruction processing unit 108 performs reconstruction processing after the above-described parallax estimation. For example, in this digital image area where a virtual digital image area is prepared on the memory for the reconstructed image, each pixel of the single eye image to be reconstructed is determined based on the parallax estimated for the single eye image. Relocate to the specified position. By repeating such an operation, a single image having a finer vein pattern than the original single-eye image can be reconstructed on the digital image area.

  FIG. 20 shows an overall processing flow of the personal authentication apparatus according to the present embodiment. The correspondence between the processing steps in FIG. 20 and the processing steps in FIG. 16 is as follows. Step 401 is Step 301, Step 402 is Step 302, Step 403 is Step 303, Step 404 is Step 304, Step 405 is Step 305, Step 406 is Step 306, Step 408 is Step 307, Step Reference numeral 409 denotes a processing step corresponding to step 308. Step 407 is a processing step by the reconstruction processing unit 108, and performs processing for reconstructing a single image from the plurality of authentication single images determined in step 404.

  In the present embodiment, the compound eye image input by the compound eye imaging unit 101 is composed of a set of a large number of individual images as schematically shown in FIG. In FIG. 21, it is assumed that the left and right are in the x direction and the top and bottom are in the y direction. In step 402, the subject position determination unit 102 extracts the single-eye images arranged in the y direction with diagonal lines as single-eye images set for position determination, and in step 403, contour extraction is performed on the single-eye images. In step 404, one single-eye image is determined as a position determination single-eye image from among the single-eye images, for example, by the method described with reference to FIG. For recognizing a plurality of single-eye images set for recognition included in the same set as the images, that is, a plurality of single-eye images set for recognition on the same x-direction column as the position determination single-eye images Determined as a single eye image. In step 405, position determination is performed using the position determination single-eye image determined in step 404. In step 407, the reconstruction processing unit 407 reconstructs a single image from the plurality of recognition single-eye images determined in step 404.

  In step 408, when the registration operation is selected, the registration processing unit 107 stores the reconstructed image obtained by the reconstruction processing unit 108 as a registration pattern. When the authentication operation is selected, the authentication processing is performed. The unit 104 performs authentication processing by pattern matching or feature-based matching between the reconstructed image by the reconstruction processing unit 407 and the registered pattern stored in the authentication processing unit 107.

  Note that the subject position determination unit 102, the position correction unit 103, the authentication processing unit 104, and the registration processing unit 107 shown in FIG. 1 or 18 can be realized as dedicated hardware, but all or one of them can be realized. The unit may be realized by software using a computer such as a microcomputer including a microprocessor, ROM, RAM, and the like, and a computer-readable recording medium on which the program is recorded are also included in the present invention.

  In other words, as shown in FIG. 2, FIG. 16, or FIG. 20, a step of inputting a compound eye image of a living body part using a compound eye imaging unit, a processing step by a subject position determination unit, a processing step by a position correction unit, authentication A program for causing a computer such as a microcomputer to execute a processing step by the processing unit and further a processing step by the reconfiguration processing, and a computer-readable recording medium on which the program is recorded are also included in the present invention.

  FIG. 22 shows an example of a system in which the above-described personal authentication device of the present invention is connected as an authentication device 1000 to an information device 1100 such as a personal computer. In such a system, for example, only the compound eye imaging unit 101 and the position correcting unit 103 of the personal authentication device are mounted on the authentication device 1000 as hardware or software, and other elements of the personal authentication device, that is, the subject position determination unit 102, The configuration processing unit 108, the authentication processing unit 104, and the registration processing unit 107 may be implemented as software in the information device 1100.

  As mentioned above, although embodiment of this invention was described, this invention is not limited only to such embodiment, Various modifications are included.

DESCRIPTION OF SYMBOLS 101 Compound eye imaging part 102 Subject position determination part 103 Position correction part 104 Authentication process part 105 Position correction guide part 106 Position correction moving means 107 Registration process part 108 Reconstruction process part 11 Lens array 12 Light-shielding member 13 Imaging element 14 Cover glass

JP 2007-219 A JP 2006-107401 A

Claims (5)

Compound eye imaging means comprising: a lens array in which a plurality of lenses are arranged on a substantially plane; and an imaging element that images a user's living body part held over the lens array as a compound eye image that is a set of a plurality of single-eye images. ,
Contour extraction processing for extracting a contour of a living body part is performed using a single- eye image set for position determination in a compound eye image captured by the compound eye imaging means, and the compound eye imaging is performed based on a result of the contour extraction processing. Position determining means for performing position determination for determining whether or not the position of the biological part relative to the means needs to be corrected and a method for correcting the necessary position;
According to the method for correcting the necessary position determined by the position determination means, the means for guiding the user is guided to the user for movement for correcting the position of the living body part, or the compound eye Position correcting means for moving the compound eye imaging means for correcting the position of the living body part by means for moving the imaging means;
An authentication processing unit that performs an authentication process using a single-eye image set for authentication in a compound eye image captured by the compound eye imaging unit when it is determined by the position determining unit that correction of the position of the living body part is unnecessary ; ,
A personal authentication device having
There are a plurality of combinations of single-eye images set for the position determination and single-eye images set for the authentication,
The position determination means uses, as a position determination single-eye image, a single eye image set for position determination based on a result of contour extraction processing of a single-eye image set for position determination for each pair. Determine the position based on the result of the contour extraction processing of the position determination single-eye image,
The personal authentication apparatus, wherein the authentication processing means performs an authentication process using a single eye image set for authentication in the same set as the single eye image for position determination determined by the position determination means. In each set, there are multiple single images set for authentication,
From a plurality of single-eye images set for authentication in the same set as the single-eye images for position determination determined by the position determination means, a single image having a higher resolution is reproduced using parallax between single-eye images. Further comprising reconfiguration processing means to configure,
The personal authentication apparatus according to claim 1, wherein the authentication processing unit performs a recognition process using a reconstructed image obtained by the reconstruction processing unit. From a compound eye imaging means comprising a lens array in which a plurality of lenses are arranged on a substantially plane, and an imaging element that images a user's living body held over the lens array as a compound eye image that is a set of a plurality of single-eye images An input step for inputting a compound eye image of a living body part;
Based on the single-eye image set for position determination in the compound eye image input in the input step, contour extraction processing for extracting the contour of the living body part is performed, and the compound eye imaging means is performed based on the result of the contour extraction processing. A position determination step for performing position determination for determining whether or not the position of the relative position of the living body part needs to be corrected and a method for correcting the necessary position;
According to the method for correcting the necessary position determined by the position determining step, the user guides the movement for correcting the position of the living body part by means for guiding the user, or the compound eye A position correcting step for moving the compound eye imaging means for correcting the position of the living body part by means for moving the imaging means;
An authentication process step of performing an authentication process with a single-eye image set for authentication in the compound eye image input by the input step when it is determined that the correction of the position of the living body part is unnecessary by the position determination step;
A program for causing a computer to execute
There are a plurality of combinations of single-eye images set for the position determination and single-eye images set for the authentication,
In the position determination step, a single-eye image set for position determination of one set based on a result of contour extraction processing of the single-eye image set for position determination of each set is used as a single image for position determination. Determine the position based on the result of the contour extraction processing of the position determination single-eye image,
The authentication processing step performs authentication processing using a single eye image set for authentication in the same set as the single eye image for position determination determined in the position determination step. In each set, there are multiple single images set for authentication,
From a plurality of single-eye images set for authentication in the same set as the single-eye images for position determination determined in the position determination step, a single image having a higher resolution is reproduced using parallax between single-eye images. Further comprising a reconfiguration processing step to configure,
The program according to claim 3, wherein the authentication processing step performs recognition processing using a reconstructed image by the reconstruction processing means. A computer-readable recording medium on which the program according to claim 3 or 4 is recorded.

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