JPH11203478A - Iris data acquiring device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve the precision of personal identification by generating iris data from a composite image obtained by complementing the excluded part of any one of plural iris images by using one part of the other iris image. SOLUTION: In a photographing control part 3, plural illuminations 2-1 to 2-4 are arranged around a camera 1 for photographing the eye of an object person, these respective illuminations 2-1 to 2-4 are emitted at various kinds of timing different in time, the image of the eye is photographed by the camera 1 every time and plural iris images are acquired. Then, the images in the areas including highlight of the illuminations 2-1 to 2-4 are excluded from the iris images by a highlight excluding part 6 of an image processing part 5, the synthetic image is provided by complementing the excluded part of any one iris image while using one part of the other iris image at a composition part 7, and it is data are generated from that composited image by an iris data generating part 9.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] 1. Field of the Invention [0002] The present invention relates to an iris data acquisition device in a system for performing individual recognition based on an image of a human eye.

[0002]

2. Description of the Related Art The use of iris data has been put to practical use for purposes such as managing the access of buildings, confirming the identity of an automatic transaction device of a financial institution, and preventing unauthorized use. The iris data is obtained by extracting predetermined characteristic data from an iris image, and is attracting attention as information that enables extremely accurate personal recognition, similar to a fingerprint. In particular, the development of a system that automatically captures the eyes of approaching people with a camera and acquires iris data eliminates the need for possession of an ID card or the like, and enables automatic personal recognition without contact. It has high practicality.

[0003]

However, the conventional iris data acquisition device as described above has the following problems to be solved. An iris data acquisition device that automatically photographs a person's eyes when a person approaches is provided with a photographing light and a camera. However, when the eyes are photographed with the camera by illuminating the illumination, the illumination device is reflected in the image of the eyes, making it difficult to obtain complete iris data. Therefore,
The illumination is arranged far away from the camera, and the illumination angle and the like are devised to prevent the illumination device from being reflected. However, such a configuration has a problem in that the size of the lighting, its supporting device, and the camera becomes large, and it is not easy to incorporate it into various devices such as an automatic transaction device.

In addition, if the iris data is generated while allowing some reflection of the illumination device, the recognition accuracy is reduced, and the eye image must be re-photographed to confirm the identity, or In the worst case, there was also a problem that identity verification became impossible.

[0005]

The present invention employs the following structure to solve the above problems. <Configuration 1> A camera that captures an image of the subject's eye, a plurality of lights arranged around the camera for capturing the eyes, and each of these lights emits light at different timings. Each time the camera shoots an image of the eyes, a photographing control unit that controls to acquire a plurality of iris images, and, from the plurality of iris images acquired by the camera, an image of an area including a highlight of illumination, respectively. An iris data acquisition device, comprising: an image processing unit that generates iris data from a composite image in which a part excluded from any one of the iris images is complemented by using a part of another iris image.

<Structure 2> In the apparatus described in Structure 1,
By combining a plurality of iris images, a composite image obtained by complementing one of the iris images with another iris image is obtained, and the consistency of the joint is determined. An iris data acquisition device, comprising: a consistency determination unit that controls so as to obtain a composite image by another combination of images.

<Structure 3> In the device described in Structure 2,
The iris data acquisition device, wherein the consistency determining unit determines whether there is any mismatch by comparing an image of a joint portion of the combined image with a corresponding portion of another iris image.

<Structure 4> In the device described in Structure 2,
An iris data acquisition device, wherein the consistency determination unit detects discontinuity of code data and determines presence / absence of mismatch when generating iris data from a composite image.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below using specific examples. FIG. 1 is a block diagram of an iris data acquiring apparatus according to the present invention. The device shown in the figure is provided around, for example, four lights 2-1 to 2-
4 are arranged. By illuminating these lights, the camera 1 captures an image of the eyes of a person (not shown) approaching the left side of the figure. The imaging control unit 3
As will be described later, this is a part that performs control to cause the illuminations 2-1 to 2-4 to emit light in a predetermined order, and further performs control to cause the camera 1 to perform a shooting operation at a timing when any of the illuminations emits light. Therefore, it is composed of switches, relays, etc. that operate in a certain sequence.

The iris image 4 captured by the camera 1 is configured to be transferred to an image processing unit 5. The image processing unit 5 includes a highlight exclusion unit 6, a synthesis unit 7, a consistency determination unit 8, and an iris data generation unit 9. The image processing unit 5 includes an iris image 4 acquired by the camera 1.
Is processed on a computer to obtain iris data for identity verification.

First, the effect of illumination during photographing will be described with reference to FIG. FIG. 2 is an explanatory diagram of highlights. FIG. 2A shows an image 10 obtained by capturing an image of an eye under ideal conditions. The black circle at the center is the image of the pupil. If you do this with the lights in close proximity to the camera,
For example, as shown in (b), the iris image includes a white circle portion where illumination is reflected. This white circle is hereinafter referred to as highlight 11.

The iris data is generated by encoding characteristic image data around the iris at the center of the pupil. Therefore, if the highlight 11 as shown in this figure is included, a defect occurs in the iris data. Therefore, it is conceivable that the illumination is moved away from the camera so that such highlights do not occur, and the eyes are illuminated at a further angle.
FIG. 2C shows an image 10 obtained under the conditions.
It is.

The highlight 11 shown in FIG. 1 exists at a position farther from the iris, and an image of the iris can be obtained in almost perfect form. Therefore, defect-free iris data can be obtained. However, when performing such shooting, the lighting must be located far enough from the camera,
Inevitably increases the size of the iris data acquisition device. In the present invention, a defect-free iris image is synthesized by using a plurality of iris images captured and acquired in the state shown in FIG.

FIG. 3 shows an operation time chart of the photographing control section 3 shown in FIG. In order to achieve the above object, in the present invention, photographing is performed, for example, at the timing shown in FIG. (A) is the shutter timing of the camera, and four shots are taken at fixed time intervals such as times t1, t2, t3, and t4. (B) Illumination 2-
1, (c) is illumination 2-2, (d) is illumination 2-3, (e)
Indicates the light emission timing of the illumination 2-4.

As shown in FIG. 1, each illumination emits one light at a different timing. Then, the shutter of the camera 1 operates at the timing when each illumination emits light, and an image is taken. The four iris images 4 obtained in this manner have different highlight positions because they emit different illuminations at the time of photographing.

FIG. 4 is a diagram for explaining the operation of the image processing section 5. As shown on the left side of FIG.
When the iris image is shot by emitting light, the iris image 12-1
Shall be obtained. Also, when the image is taken with the illumination 2-2 emitting light, the iris image 12-2 is acquired and the illumination 2
-3, the iris image 12-3
Is acquired, and it is assumed that the iris image 12-4 is acquired when the image is captured with the illumination 2-4 emitted. The positions of the highlights 11 reflected on these are shifted by about 90 ° in the circumferential direction. This is because each illumination just surrounds the camera and its arrangement is shifted by 90 °.

Although the number of highlights is set to one here, in many cases, a plurality of highlights are included in consideration of various conditions and room lights in the vicinity. In any case, the highlight elimination unit 6 shown in FIG. 5 can exclude the portion by scanning the iris image and detecting an area where the brightness differs by a certain amount or more. For example, in the example shown in FIG. 4, just one quarter of the iris image is automatically cut out to exclude highlights. Other iris image 1
By performing the same processing for 2-2 to 12-4, the iris images 13-1 to 13-1 with the highlights cut off
3-4 is obtained.

Here, for example, an iris image 13-1 whose upper left portion has been cut out is used as an original image, and a complementary iris image 13 cut out from another iris image 13-2.
-5 is obtained. Iris image 13-1 and iris image 13
When -5 is combined, a composite image 14 having no defect as shown on the right side of the figure is obtained. The combining unit 7 shown in FIG.
In this way, an operation of complementing the excluded part of one of the iris images by using a part of the other iris image is performed.

The consistency judging section 8 shown in FIG. 1 checks the consistency of the joint portion of the composite image 14 thus obtained.
The joint is an iris image 13-1 which is an original image.
And the joint portion of the iris image 13-5 which is the complementary image. For this determination, for example, another iris image 13-4 is used as shown in FIG. An image 15A of a part of the iris image 13-4 corresponding to the above-described junction.
And 15B are compared with the image of the joint.

If they substantially match, it is determined that they match, and if there is a difference greater than a predetermined value, it is determined that they do not match. Matching means that the composite image 14 is an almost perfect iris image. Therefore, using this, the iris data generation unit 9 shown in FIG. 1 performs a well-known iris image generation process. In other words, ring-shaped image data is obtained from a circular iris image, and the change in density in the circumferential direction is encoded.

On the other hand, if the consistency judgment section 8 judges that there is no consistency, another combination of iris images is selected and the images are synthesized again. That is, for example, the iris image 12-3 shown in FIG.
A composite image is obtained using 2-4 as a complementary image. In this way, a combination obtained by performing various combinations to obtain a complete composite image is used for generating iris data.

FIG. 5 is an operation flowchart of the apparatus of the present invention. The overall operation of the apparatus of the present invention will be described with reference to FIG. First, in step S1, the illuminations 2-1 to 2-4 described above are sequentially emitted, and images having different highlight positions are continuously photographed while changing the emission positions. Next, in step S2, a portion including the highlight of each image is cut. And step S
In 3, the combination of the original image, the complementary image, and the check image is determined.

Step S4 is a part for determining whether or not the check has been completed for all combinations. If no match is found even if the match is determined for all combinations, the result of this step S4 is YES (Y), and the process proceeds to error processing. In other words, the procedure is to take the image of the eye again. In step S5, a composite image is created from the original image and the complementary image, and a check is performed using the check image.

Then, in step S6, it is determined whether there is any mismatch. If there is no mismatch, iris data generation is performed using the combination of the original image and the complementary image as described above. If inconsistency is determined, step S
3, the process proceeds to a process of determining another combination and creating a composite image again. In this way, the process proceeds while changing the combination until a consistent composite image is obtained.

Note that, in the above example, 4
Although a plurality of illuminations are arranged to emit light at different timings in time, at least two or more illuminations may be used, and the number of illuminations is arbitrary. Further, a plurality of lights may be simultaneously turned on as necessary. Note that, in the present invention, since photography is performed to allow highlighting by lighting, the lighting may be arranged in the immediate vicinity of the camera. The closer the lighting is to the camera, the smaller the mechanism for holding the camera and the lighting, and the easier it is to incorporate it into an automatic transaction device or the like.

The highlight elimination unit 6 has been described as excluding highlights by analyzing iris data. However, in an environment where there is no influence other than the illumination used for photographing, the position and number of highlights may be reduced. It becomes constant by the light emitted in advance. Therefore, by removing a portion that is predicted to be reflected in advance for each light that has been emitted, highlight exclusion processing can be easily performed. The method of combining and combining images can be freely changed.

In addition, the matching is determined by comparing the image of the joint with the corresponding portion of the other iris image. For example, when generating iris data from a composite image, the discontinuity of the code data is determined. You may make it detect. Since the iris data is obtained by coding the density of the annular image in the circumferential direction, the density changes are continuous and cannot be abrupt. Therefore, a portion where the discontinuity of the code data exists can be determined to be a portion where a mismatch has occurred during synthesis. According to such a method as well, it is possible to exclude inconsistent synthesized images and generate more complete iris data.

[0028]

According to the iris data acquiring apparatus of the present invention described above, since the photographing is performed while allowing the existence of the highlight, the illumination can be arranged close to the camera, and the photographing mechanism can be downsized. In addition, since images excluding highlights are synthesized and iris data is obtained based on an iris image having no defect, there is an effect that the accuracy of personal identification using iris data is improved. Therefore, it is possible to compactly integrate and operate the highly accurate iris data acquisition device in an automatic transaction device such as a financial institution.

[Brief description of the drawings]

FIG. 1 is a block diagram of an iris data acquisition device according to the present invention.

FIG. 2 is an explanatory diagram of highlights.

FIG. 3 is an operation time chart of a photographing control unit.

FIG. 4 is a diagram illustrating the operation of an image processing unit.

FIG. 5 is an operation flowchart of the apparatus of the present invention.

[Explanation of symbols]

 Reference Signs List 1 camera 2-1 to 2-4 illumination 3 shooting control unit 4 iris image 5 image processing unit 6 highlight elimination unit 7 synthesis unit 8 consistency determination unit 9 iris data generation unit

Claims (4)

[Claims] A camera for photographing an image of an eye of a subject; a plurality of lights arranged around the camera for photographing the eyes; and illuminating each of these lights at different timings. In each case, let the camera take a picture of the eye,
A photographing control unit that controls to acquire a plurality of iris images; and, from the plurality of iris images acquired by the camera, excluding an image of a region including a highlight of illumination, and an exclusion portion of any one of the iris images. An iris data acquisition device comprising: an image processing unit that generates iris data from a composite image obtained by complementing the iris image using a part of another iris image. 2. The apparatus according to claim 1, wherein a combined image obtained by complementing any one of the iris images with another iris image is obtained by combining a plurality of iris images, An iris data acquisition device comprising: a consistency determination unit that controls so as to obtain a composite image by another combination of a plurality of iris images when there is a mismatch. 3. The apparatus according to claim 2, wherein the consistency determining unit compares the image of the joint portion of the composite image with a corresponding portion of another iris image to determine whether there is a mismatch. Characterized iris data acquisition device. 4. The apparatus according to claim 2, wherein, when generating the iris data from the composite image, the consistency determining unit detects discontinuity of the code data and determines presence / absence of the mismatch. Characterized iris data acquisition device.