JP3504313B2 - Personal identification device - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a personal identification device for identifying an individual based on a fundus image photographed and stored by a fundus camera or the like.

[0002]

2. Description of the Related Art Conventionally, an ophthalmologic apparatus such as a fundus camera
An ophthalmic image is electronically photographed using a solid-state image pickup device such as an area CCD, and the electronically picked-up video signal is transferred to an information storage / reproduction device such as a still video device or an optical disc device by a calculation control circuit, and the still video disc, floppy disc
There is known a personal identification device that is stored in a storage medium such as an optical disk and that identifies a person by comparing a past fundus image stored in this storage medium with a new fundus image newly captured electronically. ing.

At this time, the eye fundus image is photographed at a fixed position by fixing the line of sight with a fixation target, and the fundus image photographed at this fixed position is taken on a predetermined locus. Video signal is being extracted.

[0004]

By the way, in such a personal identification device, a fundus individual is obtained by extracting a video signal based on a fundus image electronically photographed in a state where the line of sight is fixed by a fixation target. In order to store information, if the line of sight is misaligned, the extraction position of the video signal corresponding to the past fundus personal information does not match the extraction position of the video signal corresponding to the current fundus personal information, resulting in an error. There is a risk of recognition and a new problem of low reliability arises.

The present invention has been made in view of the above circumstances, and provides a personal identification device which can always extract a video signal at a fixed position regardless of a shift in the line-of-sight direction and improve reliability. The purpose is to do.

[0006]

In order to achieve this object, the invention described in claim 1 is an image of a fundus image including a nipple.
Detecting the papilla center position based on the signal, the fundus personal information detected and detecting means for detecting the position of the blood vessel image from said detected papilla center position to extract a video signal on a predetermined trajectory, by detecting means And a discriminating means for personally discriminating based on the past fundus personal information stored in the storage means and the present fundus personal information detected by the detecting means. And

[0007]

In such a structure, the detecting means detects the center position of the nipple from the fundus image and the position of the blood vessel image based on the video signal extracted from the center position of the nipple on a predetermined locus, and the storing means. The fundus personal information detected by the detecting means is stored by the, and the personal identification is performed based on the past and present fundus personal information detected by the detecting means by the identifying means.

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, an embodiment of the personal identification device of the present invention is shown in FIG.
It will be described with reference to FIG.

FIG. 1 is an explanatory diagram of an optical system of a fundus camera for obtaining a fundus image used in the personal identification device of the present invention.

In FIG. 1, 10 is an observation illumination optical system of the fundus camera, 30 is a photographing illumination optical system of the fundus camera, 4
Reference numeral 0 is an observation / photographing optical system of the fundus camera, and 50 is a fixation target optical system of the fundus camera.

[Observation illumination optical system 10] Observation illumination optical system 1
Reference numeral 0 denotes an observation light source (for example, a halogen lamp) 11, a condenser lens 12, a condenser lens 13, a small-diameter light shielding plate 14, a ring diaphragm 15, a small-diameter light shielding plate 16, a relay lens 17, a reflection mirror 18, a relay lens 19, and a black dot. It has optical components such as a plate 20, a relay lens 21, a perforated mirror 22, and an objective lens 23.

The illumination light for observation from the observation light source 11 is
It is projected onto the fundus EF through each optical component from the condenser lens 12 to the objective lens 23.

The small-diameter light-shielding plate 14 is conjugated with the cornea EC, the ring-shaped diaphragm 15 is conjugated with the pupil EP, and the small-diameter light-shielding plate 16 is conjugated with the rear surface of the lens EL. The black spot plate 20 is for preventing the reflected light on the surface of the objective lens 23 from passing through the hole portion 22 a of the perforated mirror 22.

[Photographing illumination optical system 30] Photographing illumination optical system 3
Reference numeral 0 denotes an imaging light source (for example, a xenon lamp) 31, exciter filters 32 and 32 'that can be inserted into and removed from the observation / imaging illumination optical path indicated by the optical axis O1, and optical components such as a condenser lens 13 to an objective lens 23 in this order. . The photographing illumination light from the photographing light source 31 is projected onto the fundus EF through the optical components from the condenser lens 13 to the objective lens 23.

Exciter filter 3 for visible fluorescence, which has a characteristic of transmitting visible light and blocking infrared light during visible fluorescence photography.
2 is used, and an exciter filter 32 'for infrared fluorescence having a characteristic of transmitting infrared light and blocking visible light is used during infrared fluorescence photography.

[Observation / photographing optical system 40] The observation / photographing optical system 40 includes an objective lens 23 facing the eye E to be inspected, a hole 22a of the perforated mirror 22, and an observation / photographing optical path shown by the optical axis O2 in FIG. Removable barrier filters 41, 41 ', a focusing lens 42, an imaging lens 43, a reflection mirror 44, a mask 45, a field lens 46 conjugate with the fundus EF, a reflection mirror 47, a relay lens 48 and the like are provided in this order.

A visible fluorescent barrier filter 41 having a characteristic of transmitting visible light and blocking infrared light is used during visible fluorescent photographing, and an infrared fluorescent barrier filter 41 'is used during infrared fluorescent photographing.

The image formed by the reflected light from the fundus EF passes through the objective lens 23, the hole 22a of the perforated mirror 22, the reflection mirror 44, the mask 45, the field lens 46, the reflection mirror 47, and the relay lens 48, and then the television camera. 49
An image is formed on the area CCD 49a of the
The video signal of the image formed on is input to the display means 61 such as a monitor via the fundus image control circuit 60, and the display means 6 is displayed.
A fundus image F (see FIG. 2) is displayed on the screen 1 in real time.

The photographing light source 31, the condenser lens 13, the exciter filter 32, and the barrier filter 41 described above are used for fluorescent photographing, and are basically visible or infrared in the personal identification device of the present application. It does not need to be performed because it is not necessary to perform the fluorescence imaging.

[Fixation Target Optical System 50] Fixation target optical system 50
Is a half mirror 51 that is detachably arranged between the imaging lens 43 and the reflection mirror 44, and has a small hole 52a as a fixation target, and is a fixation target that is arranged conjugate with the fundus EF. The mask 52 and the fixation target light source 53 such as a light emitting diode, which is disposed so as to face the small hole 52a.

The illumination light from the light source 53 for fixation target passes through the small hole 52a of the mask 52, is reflected by the half mirror 51, is guided to the observation / photographing optical path, and is projected on the fundus EF.

[Ocular fundus image control circuit 60] The fundus image control circuit 6
0 has an arithmetic control circuit 62 as shown in FIG.

The arithmetic control circuit 62 has various conditions (for example,
A drive signal is output to a camera drive unit 63 having a mirror drive device, a drive motor, or a light source control circuit that is driven according to a focusing operation or a photographing operation). The camera drive unit 63
Is controlled based on an output signal from a camera operation unit 64 having a mode setting switch, a photographing condition input device, a photographing switch, or the like.

The arithmetic control circuit 62 is an area CCD.
49a, a frame memory 65, a video processing circuit 66, a display means 61, and a video display system such as an information storage / playback device 67 such as an optical disk device or a floppy disk device for storing the fundus image F stored in the frame memory 65. To do. The fundus image F captured by the area CCD 49a is
The information is stored in a storage medium such as an optical disk or a floppy disk via the information storage / playback device 67, and the fundus image F is called up on the display screen of the display means 61.

Further, the arithmetic control circuit 62 has a fundus image F
The nipple center position P of the nipple ED is detected, and a video signal on a predetermined locus is extracted from the nipple center position P to obtain a blood vessel image B.
Blood vessel image detection circuit (detection means) for detecting positions 1 to B4
68, blood vessel images B1 to B detected by the blood vessel image detection circuit 68
4, a personal identification circuit (identification means) 69 for performing personal identification based on the fundus personal information such as the position and thickness, and a personal information storage device (storage means) for storing the fundus personal information detected by the blood vessel image detection circuit 68. 70 is connected.

Next, the data processing function of the arithmetic control circuit 62 for observation, photographing, storage, identification, etc. will be described.

[Observation] When the power of the fundus camera body (both not shown) is turned on, the arithmetic control circuit 62 first turns on the observation light source 11. From this state, focusing work including alignment with respect to the fundus EF is performed, and when this focusing work is completed, the illumination light from the observation light source 11 is projected onto the fundus EF via each optical component of the observation illumination optical system 10. Be reflected and reflected.

On the other hand, the reflected light from the fundus EF is composed of optical components from the objective lens 23 of the observing / photographing optical system 40 to the image forming lens 43, a reflecting mirror 44, a mask 45, a field lens 46, a reflecting mirror 47, and a relay lens. It is guided to the area CCD 49a of the television camera 49 via 48 and the like, whereby the fundus image F is formed on the area CCD 49a.

The arithmetic control circuit 62 scans the entire area CCD 49a to read the video signal of the fundus image F for one frame when constructing the video signal for the first frame, and reads the video signal for one frame. To memorize.

After that, the arithmetic control circuit 62 transfers the video signal of the fundus image F of the frame memory 65 to the video processing circuit 66, and the fundus image F is displayed on the display means 61 via the video processing circuit 66. It is possible to observe the fundus image F in real time.

[Visible Color Photography] After such an observation, various filters (not shown) are arranged in each optical system, and then the photographing switch 73 is turned on to turn on the photographing light source 31.
To control the emission of light, guide the photographing light from the photographing light source 31 to the fundus EF via the photographing illumination optical system 30, and guide the reflected light from the fundus EF to the area CCD 49a via the observation / photographing optical system 40. By doing so, fundus imaging is performed.

Then, the image signal of the area CCD 49a is displayed on the display means 61 as a fundus image F after photographing, in the same manner as in the above-described observation.

[Fluorescence Imaging] When performing visible / infrared fluorescence imaging of the fundus EF, fluorescein (for visible fluorescence imaging) or indocyanine green (for infrared fluorescence imaging).
Exciter filter 32 for visible fluorescence while injecting
An exciter filter 32 'for infrared fluorescence (for photographing fluorescence) and an exciter filter 32' for infrared fluorescence (for photographing infrared fluorescence) are inserted into each optical path, and the photographing light source 31 is caused to emit light to photograph the fundus EF. The fundus image obtained by this fluorescence photography can also be used as the fundus individual identification information.

[Memory] Fundus image F photographed in this manner
The video signal of is stored in a storage medium such as an optical disk, a floppy disk, a still video disk via the information storage / playback device 67. The storage medium described above stores a large number of shooting condition information corresponding to video signals such as ID number, name, age, sex, right / left eye, shooting light amount, and type of filter at the time of shooting.

[Identification] On the other hand, the personal information storage device 70 stores the fundus personal information for identification detected by the blood vessel image detection device 68.

This fundus personal information is used as the blood vessel image detection circuit 68.
A nipple ED that has a high density and is easy to identify in the fundus image F due to
The nipple center position P of the nipple is detected and, for example, a radius corresponding to 1.5 times the nipple ED from the nipple center position P (see FIG. 2).
The positions of the blood vessel images B1 to B4 are detected by extracting the video signals located on the circular locus indicated by the solid line), and the positions of the blood vessel images B1 to B4 and the thickness of the blood vessel images B1 to B4 are determined as density levels. It is based on a graph (see FIG. 4) of (vertical axis) and angle (horizontal axis).

For example, an image portion having a preset threshold level or higher is extracted, and the teat center position P of the teat ED is determined by the position of the center of gravity of this image portion.

Next, a video signal on a predetermined radius is extracted from the determined teat center position P, and the level of the other retina parts other than the teat ED of the extracted video signal (relatively rising and falling slowly). The peaks p1, p2, p3, p4 of the video signal having a high level relative to (part) are determined to be the positions of the blood vessel images B1 to B4, and the widths a, b, from the start of the rapid change to the end of the change are determined.
It is determined that c and d are the thicknesses of the blood vessel images B1 to B4.

Then, each peak p1, p2, p3, p4
And the angular components of widths a, b, c, and d are stored in the personal information storage device 70 as fundus personal information.

Further, the past fundus personal information for each fundus image F stored and stored in the personal information storage device 70 as an angular component by the above-described photographing procedure is the fundus personal information of the newly detected fundus image F. Is calculated by the individual identification circuit 69 to identify the individual.

For example, the fundus personal information of the blood vessel image detection circuit 68 corresponding to the graph result shown in FIG. 4 is the current fundus personal information, and the graph result shown in FIG. 5 (A in FIG. 5 indicates a in FIG.
In the following, B, C, D, and P in FIG. 5 are b, c, d, and
If the fundus personal information of the blood vessel image detection circuit 68 corresponding to (corresponding to p) is one of the past fundus personal information stored and stored in the personal information storage device 70, first of all, the fundus personal information of the past. ₁ and the current fundus personal information, ε ₁ = (A−a) ² + (B−b) ² + (C−c) ² + (D−d) ² + (P 1 −p 1) ² + ( P2-p2) ² + (P3-p3) ² + (P4-p4) ² (1)

Next, all of the past fundus personal information (ε _{2 to} ε _i ) accumulated in the same manner and the current fundus personal information are individually calculated by the above equation (1).

The past fundus personal information (ε ₁
~ Ε _i ), the past fundus personal information corresponding to the current fundus personal information exists when the past fundus personal information that has the smallest numerical value (including match) is less than or equal to a predetermined value. Then, the individual is identified and judged.

The above-mentioned predetermined value means that when the minimum value obtained by the equation (1) is larger than this predetermined value, there is no past fundus personal information corresponding to the current fundus personal information. This is for making a judgment, and is effective when there is not necessarily any one corresponding to the current fundus personal information in the past fundus personal information. Therefore, when the past fundus personal information corresponding to the present fundus personal information is always present, the setting of this predetermined value is unnecessary.

When such a personal identification device is used for the above-mentioned ophthalmic examination, the fundus image F corresponding to the past fundus personal information determined to be the same as the current fundus personal information is stored. An inspection is performed such as calling out from the medium and displaying it on the display unit 61, comparing the present fundus image F and the past fundus image F to see changes over time.

By the way, in the above-mentioned embodiment, an example in which the display means 61 is connected to the fundus image control circuit 60 and the personal identification device is also used for the ophthalmic examination for displaying the fundus image F on the display means 61 has been described. For example, a door lock device is connected to the fundus image control circuit 60 and used in combination with a keyless system for unlocking the door lock when there is past fundus personal information corresponding to the fundus personal information regarding the current fundus image F. It is needless to say that the personal identification device of the present invention can be used in combination with any device that operates based on the result of personal identification based on the current and past fundus images F.

Further, as shown by the circular locus of the chain line in FIG. 2, a plurality of blood vessel images on different radii are extracted, and the fundus personal information is calculated by calculating the position and thickness of the extracted blood vessel images. It is possible to further improve reliability.
In this case, data at a plurality of positions may be averaged.

[0048]

As described above, in the personal identification device of the present invention, the center position of the nipple is detected from the fundus image, and the video signal on the predetermined locus is extracted from the center position of the nipple to extract the blood vessel image. Detecting means for detecting the position, storing means for storing the fundus personal information detected by the detecting means, past fundus personal information stored in the storing means, and present fundus personal information detected by the detecting means By providing the identification means for performing individual identification based on the above, it is possible to always extract the video signal at a fixed position regardless of the shift of the line-of-sight direction, and improve the reliability.

[Brief description of drawings]

FIG. 1 is an explanatory diagram of an optical system of a fundus camera that also uses a personal identification device of the present invention.

FIG. 2 is a front view of a fundus image displayed on a display unit.

FIG. 3 is a block diagram showing a main part of a personal identification device of the present invention.

FIG. 4 is a graph showing an example of fundus personal information.

FIG. 5 is a graph showing another example of fundus personal information.

[Explanation of symbols]

F ... Fundus image ED ... nipple P ... Nipple center position B1 ... Blood vessel image B2 ... Blood vessel image B3 ... Blood vessel image B4 ... Blood vessel image 68 ... Blood vessel image detection means (detection means) 69 ... Individual identification circuit (identification means) 70 ... Personal information storage device (storage means)

Front page continuation (72) Inventor Saeko Uchida 6-6-1, Hirai, Okayama City, Okayama Prefecture Mishiro Optical Laboratory (72) Inventor Hiroyuki Otsuka 75-1 Hasunumacho, Itabashi-ku, Tokyo Topcon Co., Ltd. (72 ) Inventor Toshihiro OKASHITA No. 75, Hasunuma-cho, Itabashi-ku, Tokyo Topcon Co., Ltd. (56) Reference JP-A-53-105090 (JP, A) JP-A-5-192299 (JP, A) JP-A-57 −153635 (JP, A) (58) Fields surveyed (Int.Cl. ⁷ , DB name) A61B 5/117 A61B 3/12 G06T 7/00

Claims (2)

(57) [Claims] 1. A method for detecting a nipple center position from a fundus image
Then, extract the video signal on the predetermined trajectory from the nipple center position.
Detecting means for detecting the position of the blood vessel image, and the detecting means
Storage means for storing the detected fundus personal information, and the storage means
To the detection means and the past fundus personal information stored in the means.
Personal identification based on the detected current fundus personal information
Performing identification and means, said detecting means personal identification device you and detects the thickness of the blood vessel image at the same time. 2. A method for detecting a nipple center position from a fundus image
Then, extract the video signal on the predetermined trajectory from the nipple center position.
Detecting means for detecting the position of the blood vessel image, and the detecting means
Storage means for storing the detected fundus personal information, and the storage means
To the detection means and the past fundus personal information stored in the means.
Personal identification based on the detected current fundus personal information
And a discrimination means for performing the identifying means, you and performing personal identification by the thickness of the blood vessel image and the position of the blood vessel image personal identification device.