JPH09305765A - Method and device for identifying iris - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve the rate of recognition by removing an image which is imprinted into a subject by the reflection of environmental light. SOLUTION: An iris identifying device 1 is integrated into an automatic teller machine 2 and the iris identifying device 1 is provided with a camera 3 for shooting the iris of a person to be identified and an illumination 7 for irradiating the iris with light at the time of shooting. Before a transaction, the illumination 7 is turned off and when the person to be identified gets closer, the iris is shot by the camera 3. Then, the illumination 7 is turned on, the iris is shot and the difference is found from two pieces of aquired image data. This difference is the image of reflected light of an indoor illumination 11. Thus, the reflected component is removed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an identification method for identifying an individual by photographing the iris, which is a physical feature of the eye, and in particular, the identification accuracy is improved by removing ambient light components such as room lights. Regarding the identification method.

[0002]

2. Description of the Related Art Conventionally, a method for photographing a human iris for individual identification is disclosed in Japanese Patent Publication No. 5-84166. The iris is on the front side of the crystalline lens of the eyeball and can be photographed by the camera. The procedure for personal identification by iris photography is to first identify the human head from a distance and then identify the eye position. Then zoom in the camera and shoot the iris. When the iris is photographed, only the image of the iris is taken in and the identity is confirmed by collating with the iris image data of the person who is registered in advance.

[0003]

When the iris is photographed by a camera and the person is identified by the image data of the iris, the most serious problem is the reflected light of ambient light such as indoor lighting on the surface of the eye. This is because if an image of illumination or the like is reflected in the captured iris image, the iris image data at the time of registration will be greatly different, and recognition and verification cannot be performed normally. The reflection of ambient light causes noise in the subject image, and removal of this noise leads to improvement in the recognition rate. To prevent the effects of ambient light,
A shield called an eyecup is used, but it was not always easy to use from the viewpoint of convenience and hygiene.

[0004]

In order to solve the above problems, an iris identification method according to the present invention is a light irradiating means for irradiating an iris of a person to be identified with light for photographing by an imaging means, and the light irradiating means. And a control means for controlling irradiation and non-irradiation of
When the light irradiation unit does not irradiate, the imaging unit captures the iris to obtain a first image of the iris, and when the light irradiation unit illuminates, the imaging unit captures the iris to capture the iris image. It is characterized in that the second iris is acquired, the difference between the first and second images is taken, and the iris identification is performed based on the image obtained by removing the difference from the first image.

Further, the iris identifying apparatus according to the present invention comprises a light irradiating means for irradiating the iris of the person to be identified with light for photographing by the image pickup means, and a light irradiation controlling means for controlling the light irradiating means.
An image capturing control unit that captures the iris by the image capturing unit when the light irradiating unit does not irradiate, and an image capturing unit that captures the iris by the image capturing unit when the light irradiating unit irradiates; And an image processing unit for performing iris identification based on an image obtained by subtracting the difference between the first image pickup and the second image pickup obtained during the irradiation and removing the difference from the first image pickup. .

According to the present invention having the above-mentioned structure, the iris is photographed when the light irradiating means is not radiated, and the iris is photographed when the light is radiated, and both images are compared to obtain the difference. Assuming that this difference is the reflection component of ambient light, this difference is removed from the image data of the iris. This makes it possible to obtain an image without the reflection component. Then, the iris is identified based on the image pickup excluding the reflection component.

[0007]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a block diagram showing an iris identification device according to an embodiment. In FIG. 1, the iris identification device 1 of the embodiment is included in an automated teller machine 2. The iris identification device 1 controls a camera control unit 4 that controls the camera 3, an image processing unit 5 that processes an image captured by the camera 3, a main control unit 6 that controls the overall operation of the iris identification device 1, and an illumination 7. It is composed of the illumination control unit 8. The illumination 7 is for irradiating the person to be identified 9 with light when photographing the iris of the person to be identified 9. Iris identification device 1
Each unit of is controlled by the main control unit 6. The main controller 6
May be used also as the main control unit of the automatic teller machine 2.

The person to be identified 9 is a customer who conducts transactions with the automated teller machine 2.
There is provided a customer operation unit 10 for performing the operation. In addition, indoor lighting 11 is installed above the automated teller machine 2 and the person to be identified 9 for making the installation room of the automated teller machine 2 bright.

Next, the operation of the embodiment will be described with reference to the flowchart of FIG. FIG. 2 is a flowchart showing the operation of the embodiment. When there is no transaction, that is, when there is no customer, the lighting 7 is turned off. When the main control unit 6 commands the image processing unit 5 to detect a dynamic object, the image processing unit 5 periodically takes in the image data captured by the camera 3 and obtains the difference for each period. This operation is performed at the time of non-transaction, and thereby a dynamic object is detected. When the customer who is the person to be identified 9 approaches the automated teller machine 2, the person to be identified 9 is detected by the image processing unit 5 in this manner (step 1).

After the person to be identified 9 is identified as a customer,
The eye position is cut out based on the contour data and the like (step 2). When the position of the eye is cut out and the size of the image of the eye reaches a predetermined size, the image processing unit 5 notifies the main control unit 6 that the image of the iris can be acquired (step 3).

As a result, the main control unit 6 instructs the camera control unit 4 to acquire the image of the iris of the person to be identified 9 with the illumination 7 turned off. As a result, an iris image with the illumination 7 turned off is acquired (step 4). The acquired image is shown in FIG. As shown in the figure, an image 12 of the reflected light of the indoor illumination 11 is included in the acquired image when the light is off.

Next, the main control section 6 gives an instruction to the lighting control section 8 to turn on (turn on) the lighting 7 (step 5).
Thereby, the illumination 7 is turned on. Then, the main control unit 6 instructs the camera control unit 4 to acquire the image of the iris of the person to be identified 9 with the illumination 7 turned on. As a result, an iris image with the illumination 7 turned on is acquired (step 6). The acquired image here is shown in FIG. As shown in the figure, the image 12 of the reflected light disappears in this image.

When the image acquisition with the illumination 7 turned on is completed, the main controller 6 instructs the illumination controller 8 to turn off the illumination 7 (step 7). Then, the image processing unit 5 calculates the difference between the two acquired image data (step 8). That is, the difference between the image data when the illumination 7 is off and the image data when the illumination 7 is on is calculated. An image of this difference is shown in FIG. As shown in the figure, the indoor lighting 1 is displayed as a difference image.
Only the reflected light 12 of 1 is obtained. Then, the image data of the difference is removed from the image data obtained in step 6 to obtain the iris image data. The image data of this iris is shown in FIG. As shown in the figure, in the obtained image data, the reflection component of the light of the indoor illumination 11 is removed, and only the iris image 13 is obtained.

The main control unit 6 compares the image data from which the reflection component has been removed with the image data registered in advance to confirm the identity. At this time, since the acquired image data has high accuracy, it is not necessary to re-acquire, and the collation with the registered image data can be performed quickly. As described above, according to the above-described embodiment, since the reflection component of the indoor illumination light is removed, accurate iris image data is obtained and the identification accuracy is improved.

The present invention is not limited to the above embodiment, but various modifications can be made. For example, the on / off control of the illumination 7 for imaging the iris can be variously modified. Various modifications of the on / off control of the illumination 7 will be described below with reference to time charts.

FIG. 7 shows the on / off timing of the illumination 7, the imaging timing, and the image difference extraction timing in the above embodiment. That is, images are taken when the illumination 7 is on and when it is off, and then the difference between the images is extracted.

FIG. 8 is a time chart showing the operation timing of the first modification. In this modification, the illumination 7 is gradually linearly changed from off to on. This is done by providing the illumination control unit 8 with a variable resistor or the like. By gradually changing the brightness of the illumination 7 in this way, the psychological surprise of the customer as the person to be identified can be reduced.
Further, since the change in the brightness is gentle, the change in the pupil of the person to be identified 9 can follow the change in the brightness of the illumination 7. Therefore, the glare can be reduced, and the person to be identified 9 has less psychological resistance.

FIG. 9 is a time chart showing the operation timing of the second modification. In this modification, on / off control of the illumination 7 is continuously performed in small increments. This is done by using a clock signal or the like. As a result, the lighting 7 blinks at high speed. That is, in this modification, the illumination 7 is constantly blinking at a high speed like a fluorescent lamp in this manner.
As shown in, images are taken at the time of off and at the time of on. Therefore, since the illumination 7 does not appear to be blinking to the person to be identified 9 and it seems that the illumination 7 maintains a constant brightness, the person 9 to be identified is psychologically affected by the change in the brightness of the illumination 7. There is no effect.

FIG. 10 is a time chart showing the operation timing of the third modification. In this modified example, as in the second modified example, the main control unit 6 continuously instructs the lighting control unit 8 of the lighting 7, but the speed is slower than in the second modified example, and the person is blinking. The speed is clearly recognizable, for example, the flashing speed of a yellow light of a traffic signal. By blinking the illumination 7 at a slow speed in this manner, it is difficult for the person to be identified 9 to feel a sudden lighting, and the psychological surprise of the person to be identified 9 can be reduced.

FIG. 11 is a time chart showing the operation timing of the fourth modification. In this modification, the control of the first modification shown in FIG. 8 is continuously performed. That is, the brightness of the illumination 7 is linearly changed using a variable resistor or the like, and this is repeated. In this way, the illumination 7 blinks gently before the person to be identified 9 approaches the iris identification device 1, and as a result, there is almost no psychological effect on the person to be identified 9. When blinking before approaching the iris identification device 1, the person to be identified 9 can be psychologically prepared, and the annoyance caused by blinking is reduced.

FIG. 12 is a time chart showing the operation timing of the fifth modification. In this modification, the control of the illumination 7 is reversed from that in the above-described embodiment. That is, the illumination 7 is turned on before the person to be identified 9 approaches the iris identification device 1, and is turned off when the person to be identified 9 approaches, and images are taken in each state. In this case, the same effect as that of the above-mentioned embodiment is obtained.

FIG. 13 is a time chart showing the operation timing of the sixth modification. In this modified example, the control of the illumination 7 is reversed from that in the first modified example. That is, the illumination 7 is turned on before the person to be identified 9 approaches the iris identification device 1, and is gradually linearly turned off when the person to be identified 9 approaches. In this modification, the same effect as that of the first modification is obtained.

Although the above embodiment has been described for the iris identification device, the present invention is not limited to this, and can be applied to the application of capturing an image behind the reflection surface when capturing an object having large surface reflection. . It goes without saying that not only indoor lighting but also natural light or outdoor lighting is applicable as ambient light.

[0024]

As described in detail above, according to the present invention, the iris is photographed when the light irradiating means is not irradiating, and the iris is photographed when irradiating, and both images are compared and the difference between them is taken. . Assuming that this difference is the reflection component of ambient light, this difference is removed from the image data of the iris. As a result, the image pickup excluding the reflection component is obtained, and the iris identification is performed based on the obtained image pickup, so the identification accuracy is improved.

[Brief description of drawings]

FIG. 1 is a block diagram showing an iris identification device according to an embodiment.

FIG. 2 is a flowchart showing the operation of the embodiment.

FIG. 3 is an explanatory diagram showing an acquired image when the light is turned off.

FIG. 4 is an explanatory diagram showing an acquired image at the time of lighting.

FIG. 5 is an explanatory diagram showing a difference image.

FIG. 6 is an explanatory diagram showing an iris image.

FIG. 7 is a time chart showing the operation timing of the embodiment.

FIG. 8 is a time chart showing the operation timing of the first modified example.

FIG. 9 is a time chart showing the operation timing of the second modified example.

FIG. 10 is a time chart showing the operation timing of the third modified example.

FIG. 11 is a time chart showing the operation timing of the fourth modified example.

FIG. 12 is a time chart showing the operation timing of the fifth modified example.

FIG. 13 is a time chart showing the operation timing of the sixth modified example.

[Explanation of symbols]

 1 Iris identification device 3 Camera 5 Image processing unit 6 Main control unit 7 Illumination 8 Illumination control unit

Claims (4)

[Claims] 1. An iris identification method for identifying an identified person by capturing an image of an iris of the identified person by an image capturing means, comprising: a light irradiating means for irradiating the iris of the identified person with light for capturing the image by the image capturing means. A control unit that controls irradiation and non-irradiation of the light irradiation unit, and captures a first image of the iris by capturing the iris with the imaging unit when the light irradiation unit is not irradiating; At the time of irradiation by the irradiation means, the iris is imaged by the imaging means to obtain a second image of the iris, and a difference between the first and second images is taken to obtain an image in which this difference is removed from the first image. An iris identification method characterized by performing iris identification based on the above. 2. The iris identification method according to claim 1, wherein the control unit gently controls changes in the light irradiation unit between non-irradiation and irradiation. 3. The iris identification method according to claim 1, wherein the control unit controls the change of the light irradiation unit between non-irradiation and irradiation at high speed. 4. An iris identification device for identifying a person-to-be-identified by photographing an iris of a non-identifier by means of an image pickup means, and a light irradiation means for irradiating the iris of the person-to-be-identified with light for photographing by the image pickup means. A light irradiation control means for controlling the light irradiation means, and an image capturing method for photographing the iris by the image pickup means when the light irradiation means is not illuminated, and for photographing the iris by the image pickup means when illuminated by the light irradiation means. Iris identification based on a control means and an image obtained by subtracting the difference between the first image captured and acquired during the non-irradiation and the second image captured and acquired during the irradiation And an image processing unit for performing the above.