KR102176882B1 - Apparatus and Method for Recognizing Fake Iris By Using Minutia Data Variation - Google Patents

Abstract

Disclosed are an apparatus for discriminating a fake iris using a variation of a feature point and a method thereof. The fake iris identification apparatus of the present invention requests at least one operation to change the position of the iris or prevent the iris from being seen by the user attempting iris authentication, and then, based on whether there is a change in the feature point extracted from the photographed image. It is determined whether the iris being authenticated is a fake iris.

Description

Apparatus and Method for Recognizing Fake Iris By Using Minutia Data Variation}

The present invention relates to a counterfeit iris discrimination apparatus and method capable of discriminating a counterfeit iris among biometrics related technologies using an iris.

Iris Recognition is one of those attracting attention as a means of personal authentication. The iris is the tissue that forms the pupil of an animal by surrounding the pupil and is the most complex and sophisticated fibrous tissue in the human body. Each person has different patterns of iris, and the pattern of the iris of the left and right eyes of the same person is different. Like fingerprints, iris patterns do not change with age, so they can be used as personal authentication means.

Iris authentication uses a method of photographing an iris with a camera and comparing features of the iris portion with each other. On the other hand, personal authentication is mainly used in areas where security is important, such as access control, e-commerce, financial transactions, personal computer (PC) security, and office payment systems, so it is not a registered user, but a fake iris. It is most important to distinguish effectively (hereinafter referred to as'forged iris').

Until recently, it has been recognized that it is difficult to obtain a separate image of an iris of a specific person, and it is not easy to create a fake iris. Nevertheless, counterfeit irises such as paper on which iris images are printed on high-performance printers, or artificial eyes on which iris images are printed are found.

When such a forged iris is input into a conventional iris recognition apparatus, an iris image similar to a living iris is obtained, and through a process of extracting feature points, there is room for processing without distinction from the living iris.

[Related invention]

1. Counterfeit iris detection system and method for detecting counterfeit iris by fusing multi-spectral images (Korean Patent No. 711110)

In this invention, we propose a method of detecting a fake iris using two or more iris images captured in multi-spectral bands. In order to implement this invention, a multispectral iris imaging apparatus capable of taking images of various frequency bands is required.

An object of the present invention is to provide a counterfeit iris discrimination apparatus and method capable of discriminating a counterfeit iris and a biometric fingerprint by using variations in feature points extracted from a series of consecutively photographed eye area images.

A method for determining a fake iris according to the present invention for achieving the above object comprises the steps of: generating an eye part image by photographing a user attempting authentication by a first camera unit; Extracting an iris portion from the plurality of eye portion images generated by the first camera unit at a preset frame rate and repeating a process of extracting feature points of the iris; During the repeating step, if the position of the feature point is different among the plurality of eye area images or the variation of the feature point from which the feature point is not extracted is detected, the iris being authenticated is determined as a living body, and if the variation of the feature point is not detected, it is determined as a fake iris. It includes the step of.

User guide for counterfeiting detection

According to an embodiment, the method of determining a forged iris of the present invention may further include displaying a guide requesting at least one operation of changing the position of the iris or preventing the iris from being seen.

In this case, the repeating step is preferably performed for a predetermined measurement time after the step of displaying the guide. Further, the guidance may be, for example, a request to blink an eye or a request to gaze in a different direction by rolling the pupil.

In addition, in the determining step in the case of guiding the user, it is preferable to detect the variation of the feature point among the eye part images generated in the remaining frames except for the first frame and the last frame of the measurement time.

Meanwhile, the displaying of the guide is preferably performed when the user's eyes are recognized while the step of generating the eye part image is repeated.

Save log

The method for determining a counterfeit iris of the present invention may further include the step of generating, by the second camera unit, the user's face image and storing it together with the determination result of the determining step.

Counterfeit iris identification device

The present invention also extends to an apparatus for determining a fake iris that performs the above method for determining a fake iris. The apparatus for detecting a counterfeit iris according to the present invention includes: a first camera unit for photographing a user attempting authentication at a preset frame rate to generate a plurality of eye area images; An iris detector configured to extract an iris portion from each of the plurality of eye portion images; A feature point extracting unit for extracting feature points of an iris from the iris portion; It includes a counterfeit judgment part.

Based on the extraction result of the feature point extracting unit, the forgery determination unit determines the iris being authenticated as a living body and detects the error image when the position of the feature point is different among the plurality of eye area images or the variation of the feature point from which the feature point is not extracted is detected. If not, it is judged as a forged iris to perform a forgery determination.

The forged iris identification apparatus according to the present invention is based on whether or not there is a change in the feature point extracted from the captured image after requesting at least one operation for the user attempting iris authentication to change the position of the iris or to prevent the iris from being visible. It can be determined whether the iris being authenticated is a fake iris.

Since the method for determining a counterfeit iris of the present invention does not provide other lighting to the user attempting authentication, the user does not dazzle or cause discomfort to the user by the lighting.

In addition, the method of determining a forged iris of the present invention has a very simple structure of the device because a separate hardware device is not used to determine the forged iris.

1 is a block diagram of a counterfeit iris determination apparatus of the present invention,
2 is a flow chart provided for explaining a method for determining a fake iris according to the present invention;
3 is a block diagram of an apparatus for determining a forged iris according to another embodiment of the present invention.

The present invention will be described in more detail below with reference to the drawings.

Referring to FIG. 1, the apparatus 100 for determining a forged iris of the present invention includes a user interface 101, an image acquisition module 110 and a control module 130.

The user interface 101 is a means for displaying various guides for detecting a fake iris to the user in a visual way or outputting it to the user in an audible way. For example, a display means such as an LCD or an OLED or an audio output means such as a speaker may correspond to the user interface 101.

The image acquisition module 110 includes at least one light source 111 and at least one first camera unit 113 to acquire an iris image.

The light source 111 emits light rays of a preset wavelength toward the user's eyes in order to capture an image of the user's eyes. The wavelength of light emitted from the light source 111 may be any band, and white light may be used, but it is preferable to use infrared rays. When the infrared light source 111 is used, since the first camera unit 113 must use an infrared filter, the influence of external natural light can be excluded, and the light source 111 can provide sufficient illuminance.

The first camera unit 113 includes the lens 113a and the image sensor 113b, and generates an eye part image as an image emitted from the light source 111 and reflected from the user's eye part to be incident. When the light source 111 emits infrared rays, the first camera unit 113 may further include a filter passing through the infrared region.

Depending on the angle of view of the first camera unit 113 formed by the lens 113a, the first camera unit 113 may be configured to photograph one eye of a user or both eyes.

When the first camera unit 113 is configured to photograph one eye, the forged iris determination device 100 includes two first camera units 113 arranged in parallel to each other to photograph two eyes, respectively. You may.

The first camera unit 113 captures a user's eye portion at a preset frame rate for iris recognition, and provides a plurality of acquired eye portion images to the control module 130.

Meanwhile, as described below, the first camera unit 113 periodically photographs the front side in order to confirm the user's authentication attempt, and in this case, it may shoot at a lower speed than the preset frame rate.

The control module 130 includes an iris detection unit 131, a feature point extraction unit 133, and a forgery determination unit 135, and controls the overall operation of the forged iris determination apparatus 100 of the present invention.

The iris detection unit 131 performs a pre-processing process for determining a forged iris, and extracts the iris part from the eye part image provided by the image acquisition module 110 at a preset frame rate. The iris portion extraction can be applied to various methods known in the art. For example, since the eye area image includes all eyebrows, eyelids, etc., including the user's pupil, the outer part of the pupil is detected through edge detection in the eye area image, and the position of the pupil through Hough Transform. By detecting the position of the iris can be detected.

On the other hand, there are various ways to check the user's authentication attempt, including the user manipulating a button or confirming access with a proximity sensor. One of the methods is to use the image captured by the image acquisition module 110. will be. In this case, the iris detection unit 131 checks the degree of whether the eye part image is input from the image provided by the image acquisition module 110 and notifies the forgery determination unit 135 so that the user's authentication attempt can be confirmed. have. The image processing at this time does not have to be the degree of processing for extracting feature points from the eye part image, and for example, the degree of recognizing the contours of the face may be sufficient.

The feature point extracting unit 133 extracts information for iris authentication by extracting feature point data from the iris portion detected by the iris detecting unit 131. The feature point data extracted by the feature point extracting unit 133 includes feature points of an iris pattern peculiar to a user. In addition, iris feature points can be extracted by applying various information and extraction methods known in the art.

The forgery determination unit 135 performs a forgery determination based on the feature point data provided by the feature point extraction unit 133. The basic method of counterfeit detection is to check whether there is an error image in a series of multiple eye area images created during a set of measurement periods. Here, the error image refers to an image in which the position of the feature point and the feature point extracted from another eye area image is different during the measurement period, or the feature point is not extracted at all. When an error image is detected, the iris being authenticated is regarded as a living body. Conversely, if an error image is not detected, the iris being authenticated is regarded as a fake iris. A method of determining a forged iris by the forgery determination unit 135 will be described again below with reference to FIG. 2.

How to judge a fake iris

The basic method of determining a forged iris of the present invention is that the first camera unit 113 photographs a user attempting authentication to generate an eye area image, and the iris detection unit 131 uses the first camera unit 113 at a preset frame rate. It is performed while extracting the iris part from the plurality of eye part images generated by and repeating the process of extracting the feature points of the iris by the feature point extracting unit 133.

The forgery determination unit 135 determines the iris being authenticated as a living body when the location of the feature point is different from among the plurality of eye partial images or an error image from which the feature point is not extracted is detected, and if the error image is not detected, it determines the iris as a forged iris.

Hereinafter, a method of determining a forged iris according to the present invention will be described, focusing on the operation of the forgery determining unit 135 with reference to FIG. 2.

<Confirmation of iris authentication attempt: S201, S203>

The first camera unit 113 photographs the front at a preset frame rate, generates an image, and provides it to the control module 130. At this time, the light source 111 may or may not illuminate the front (S201).

The iris detection unit 131 detects the user's eyes by performing image processing on the image captured by the first camera unit 113. When the iris detection unit 135 recognizes the user's eyes, the forgery determination unit 135 determines that there is an attempt to authenticate the user's iris (S203).

The iris detection unit 131 may detect the outer part of the pupil through edge detection in the image of the eye area, or detect the position of the iris by detecting the position of the pupil through Hough Transform. You can also do the job.

<User guide for counterfeit detection: S205>

In step S203, the forgery determination unit 135, which recognizes the user's eyes, provides a user guide for the forgery determination to the user through the user interface 101.

As is known, the pattern of the feature point of the user's iris does not change in any state, but the position of the iris (feature point) in the eye area image captured by the first camera unit 113 may change, and the feature point cannot be extracted when the eye is closed. May be. For example, an operation of blinking an eye may occur instantaneously, and the iris from the image captured by the first camera unit 113 may be hidden. We focus on the fact that the counterfeit iris cannot perform this operation.

Therefore, the user guide for the forgery detection is to determine whether the iris attempting iris authentication by requesting an action to create a variation of the feature point extracted from the iris is forged, and to change the position of the iris or prevent the iris from being seen. Any action may be used as long as it requests at least one user action to be performed. However, a user operation that can be performed in a very short time is particularly preferable.

Accordingly, the user's motion may correspond to an action of blinking an eye, an action of rolling the pupil to gaze in a direction other than the front (eg, left, right, up or down), or an action of slightly moving the face left or right or up and down.

The user's guide for the forgery determination may be output by voice through a speaker or may be visually displayed using a display means.

<Iris recognition/ feature point extraction during measurement time: S207 to S211>

After displaying the user guide for the forgery determination, the forgery determination unit 135 turns on the light source 111 and causes the first camera unit 113 to photograph the user's eyes at a preset frame rate to create an eye part image. To be controlled. Here, the photographing speed of the first camera unit 113 may be the same as or different from the photographing speed of step S201 (S207).

The iris detection unit 131 recognizes the iris portion from the eye portion image captured by the first camera unit 113, and the feature point extraction unit 133 extracts a feature point of the iris (S209).

Steps S207 and S209 are repeatedly performed a plurality of (n) times for a predetermined measurement time, thereby generating a plurality of (n) eye area images, and iris recognition and feature point extraction are repeated a plurality (n) times. For example, when the shooting speed of the first camera unit 113 is set to 10 frames per second and the measurement time is set to 2 seconds, the iris detection unit 131 is provided with 20 (n=20) eye part images for 2 seconds. Extract feature points from Here, the measurement time is preferably set to be longer than the time required for the user to perform the guided operation according to the user guidance in step S205, and can be determined experimentally (S211).

<Fake iris detection according to error image detection: S213 to S217>

When the measurement time elapses, the forgery determination unit 135 determines whether there is an error image among the plurality (n) eye area images. Here, the error image refers to an image of an eye area in which the position of the feature point is different from that of other features or the feature point is not extracted at all (S213).

If an error image is detected among the plurality (n) eye area images, the forgery determination unit 135 determines the iris being authenticated as a living body (S215), and if no error image is detected, determines the iris being authenticated as a fake iris. ((S217).

When the user blinks his eye according to the guidance in step S205, an image of the user's eyelid moving downward and covering the iris is included among the plurality of eye area images captured during the measurement time (for example, 2 seconds). An image where the iris is covered is classified as an error image because the feature points are not properly extracted. Since the forged iris printed on paper or synthetic resin in high resolution cannot perform an operation according to the user's guidance, an error image does not occur.

Suppose that the user moves the pupil according to the guidance to move the pupil in step S205. If the user only moves the eye during the measurement period but does not blink, the same feature point can be extracted from all of the captured multiple eye area images. However, the positions of the feature points of some images are different from those of the other images. For example, if there is an image in which the location of the feature point is out of the error range based on the location of the feature point extracted from the image initially photographed after the start of the measurement time, it can be classified as an error image.

On the other hand, even if guidance is made to move the pupil in step S205, the user may blink the eye in addition to moving the pupil. Therefore, the criterion for determining the error image may be irrelevant to the guidance in step S205.

In the above method, the method of determining a counterfeit iris of the present invention is performed.

Save log

Referring to FIG. 3, the image acquisition module 310 of the forged iris detection apparatus 300 according to another embodiment of the present invention is a second camera unit that photographs a user's face image separately from the first camera module 113. (311) may be further included.

Since the second camera unit 311 photographs a face image, the second camera unit 311 has a different configuration from the first camera unit 113 that generates an eye area image. The second camera unit 311 may generate a color image of the user's face using natural light without infrared illumination.

The forgery determination unit 331 may control the second camera unit 311 to capture the user's face image when recognizing the user's eyes in step S203. The forgery determination unit 331 may store the face image photographed by the second camera unit 311 in a memory or a storage medium (not shown) together with the determination result of step S215 or S217.

The face image captured by the second camera unit 311 may be used as log data for a user who attempts iris authentication.

In the above, preferred embodiments of the present invention have been illustrated and described, but the present invention is not limited to the specific embodiments described above, and is generally used in the technical field to which the present invention belongs without departing from the gist of the present invention claimed in the claims. Various modifications are possible by those skilled in the art of course, and these modifications should not be individually understood from the technical idea or perspective of the present invention.

111: light source 113: first camera unit
113a: lens 113b: image sensor

Claims (12)

Generating an eye area image by photographing a user attempting authentication by a first camera unit;
Repeating the process of extracting the iris part from the plurality of eye part images generated by the first camera part at a preset frame rate by the iris detection unit and extracting the feature point of the iris by the feature point extracting unit for a preset measurement time;
During the repeating step, if a forgery determination unit detects a variation in feature points of an iris among the plurality of eye partial images, determining the iris being authenticated as a living body, and determining a variation in the feature points of the iris as a counterfeit iris if it is not detected. The variation of the iris feature point is that the position of the feature point of the iris is different or that the feature point of the iris is not extracted; And
And storing the generated face image in a storage medium together with the determination result of the determining step after controlling the forgery determination unit to generate the user's face image by the second camera unit. .
The method of claim 1,
The forgery determining unit further comprises outputting a guide to the user for requesting at least one operation to change the position of the iris or to prevent the iris from being seen,
The repeating step is performed for the predetermined measurement time after the step of displaying the guide.
The method of claim 2,
The guidance is a method for detecting a fake iris, characterized in that the user requests to blink their eyes or roll their eyes to gaze in a different direction.
The method of claim 2,
In the determining step,
And detecting variations in feature points of the iris from among the eye part images generated in frames other than the first frame and the last frame of the measurement time.
The method of claim 2,
And if the user's eye is recognized while repeating the step of generating the eye part image, the forgery determining unit performs the step of displaying the guide.
delete A first camera unit that photographs a user attempting authentication at a preset frame rate and generates a plurality of eye area images for a preset measurement time;
A second camera unit generating the user's face image;
An iris detection unit extracting an iris portion from each of the plurality of eye portion images;
A feature point extracting unit for extracting feature points of an iris from the iris portion; And
Based on the extraction result of the feature point extracting unit, if a variation in the feature point of the iris is detected among the plurality of eye partial images, the iris being authenticated is determined as a living body, and if the variation in the feature point of the iris is not detected, it is determined as a forged iris. And a forgery determination unit for storing the face image generated by the second camera unit together with a result of performing the forgery determination,
The variation of the iris feature point is a fake iris discrimination apparatus, characterized in that the position of the feature point of the iris is different or the feature point of the iris is not extracted.
The method of claim 7,
Further comprising a user interface for displaying a guide for requesting at least one operation of changing the position of the iris or preventing the iris from being visible to the user according to the control of the forgery determining unit,
And the forgery determining unit performs the forgery determination based on the extraction result of the feature point extracting unit extracted during the preset measurement time after displaying the guide.
The method of claim 8,
The guidance is a fake iris discrimination apparatus, characterized in that requesting a user to blink his/her eyes or to roll his/her eyes to gaze in a different direction.
The method of claim 8,
The forgery determination unit,
And detecting a variation of the feature point of the iris among the eye part images generated in frames other than the first frame and the last frame of the measurement time.
The method of claim 8,
The forgery determination unit,
And displaying the guide when the iris detection unit recognizes an eye of a user attempting iris authentication from an image provided by the first camera unit.
delete

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