KR20030077127A - Automatic focus adjustment method for using of several light for iris recognition system - Google Patents

Abstract

PURPOSE: A method for automatically adjusting a focus using a multi-illumination of an iris recognition system is provided to execute an iris recognition rapidly by omitting a repetitious focus adjusting process according to positions of illuminations when recognizing the iris with a plurality of illuminations for escaping a reflection caused by glasses of a user. CONSTITUTION: If a user accesses an iris recognition system for registering an iris image and positions one's eye at an optical axis of a camera through an optical window, one illumination out of two illuminations located in different places of an illumination device is turned on an illumination control unit and the illumination shines the iris of the user(S301). The illumination is turned on, an AE(Auto Exposure), an AF(Auto Focus), and an AZ(Auto Zoom) are executed(S302). The first iris image is extracted(S303). The illumination control unit turns on the other illumination(S304). The second iris image is extracted(S305). An iris recognition is tried using the first extracted iris image(S306). It is judges whether an iris recognition is executed using the first extracted iris image(S307). If the iris recognition is rejected caused by a reflection of glasses of the user, the iris recognition is tried using the second extracted iris image(S308).

Description

AUTOMATIC FOCUS ADJUSTMENT METHOD FOR USING OF SEVERAL LIGHT FOR IRIS RECOGNITION SYSTEM}

The present invention relates to a method for automatically adjusting the focus using multiple lights of an iris recognition system, and in particular, to perform iris recognition using a plurality of lights to avoid reflection due to wearing glasses of a user, the repetition according to the position of the lights. The present invention relates to an automatic focusing method using multiple illuminations of an iris recognition system that can perform iris recognition more quickly by omitting an automatic focusing process.

As is known, it is a system for security, crime prevention, and identity authentication. It goes beyond the existing contact or contactless card system to recognize human fingerprints, or to authenticate identity through iris recognition and access to specific places or access to specific information. Systems to allow or deny such have been prevalent.

Among them, the iris recognition system has a high recognition rate and more accurate recognition than the fingerprint recognition. The iris recognition system is a system that authenticates an individual by comparing a characteristic pattern of an iris with an image processing technology in an iris image captured by a video camera and comparing it with previously registered iris data.

1 is a view showing the configuration of a general iris recognition system, the operation of the iris recognition system with reference to the bar shown in FIG.

When the user approaches the iris recognition system, the distance measuring sensor 109 measures the distance to the user, and the controller 105 receives the distance measurement value obtained through the driver 107 to operate the distance measurement value. Determine if you are in range.

If the user is within the operating range, a control signal is sent to the driver 107 to prepare to extract the iris image. The driver 107 sends an active signal to the external indicator 108 to inform the user that the system is operating. Accordingly, when the user places the eye on the optical axis of the camera 103 through the optical window 101, the cold mirror ( 102 blocks visible light and passes infrared light. In addition, the part of the iris is displayed to allow the user to check whether the eye is located on the optical axis of the camera 103.

The controller 105 receives the distance measurement value from the distance measurement sensor 109 to the user, and calculates the zoom and focus values of the camera 103 using the distance measurement value to perform zoom in / zoom out and focusing control. Perform. Thereafter, the controller 105 allows the driver 107 to capture the iris image according to the distance measurement value, and the photographed iris image is signal-processed in the frame grabber 104 for iris image analysis, and the processed iris is processed. The image information is stored in the DB 110 (database), and with the stored information, the control device 105 performs iris recognition to determine whether the user is authenticated.

In addition, when using a single light source may cause reflection problems caused by glasses, in order to solve this problem by using a plurality of LED lights, such as the left and right, the position of the lights to avoid secondary reflection by the glasses. The image was acquired by changing.

2 is a diagram illustrating a configuration of multiple lighting devices in a general iris recognition system. As shown in the drawing, when the multiple illumination device of the iris recognition system selects and illuminates the illumination 208 by the illumination control unit 207, AE (Auto Exposure), AF (Auto Focus), and AZ (Auto Zoom) are activated. Perform.

The auto exposure (AE) measures the distance between the camera and the user at a predetermined time by the distance measuring unit 202 using the distance measuring sensor 201 and outputs continuous distance information, and the distance processing unit 203 Determines the operation characteristic of the user by using the distance information. In other words, by measuring the user's operating speed based on continuous distance information, if the speed is positive, it is determined that it is approaching, if it is negative, it is determined that it is moving away, and if the absolute speed is within the given allowable value, it is stopped. I think that.

The AZ (Auto Zoom) controls the operation of the camera when the user is stationary using information such as the distance, speed, and acceleration provided from the distance processor 203 in the camera operation controller 204. At this time, even when the user's motion is not stabilized, the time required for focusing is reduced by estimating the position where the user will stop in advance and driving the camera lens to the position.

In this manner, when the user's motion is stabilized, the zoom and focus of the camera 205 is adjusted through the camera motion control unit 204 based on the measured distance value. At this time, the user continues to move to some extent, and the measured distance value is not the distance to the real eye, so there is some measurement error. Thus, fine adjustment is performed.

In addition, AF (Auto Focus) analyzes the iris images continuously input from the image processing unit 206 in the camera operation control unit 206 to obtain a degree of focus, and zooms in until the degree of focus is suitable for performing confirmation. And continues to track in the direction of maximum value while moving the focus lens.

When AE (Auto Exposure), AF (Auto Focus), and AZ (Auto Zoom) are performed, an iris image is extracted and attempted to be recognized. However, if recognition cannot be attempted due to reflection due to user's wearing glasses, the lighting 209 at another position is turned on, and the AE (Auto Exposure), AF (Auto Focus), and AZ (Auto Zoom) are performed again. do. Then, the image is extracted and attempted to be recognized.

However, as above. If you try to avoid reflection by the glasses while changing several lights and repeat the repeated attempts of AE (Auto Focus), AF (Auto Focus) and AZ (Auto Zoom) until the iris recognition is successful, recognition speed The problem arises that the delay becomes late and the occurrence rate of the error rate becomes high.

The present invention was created to improve the above problems, and in particular, by using a plurality of lights to avoid reflection due to the user's glasses, etc., repetitive focusing adjustment according to the position of the lighting in performing iris recognition The purpose of this paper is to provide an automatic focus control method using multiple lights of the iris recognition system that can perform iris recognition more quickly by eliminating the process.

1 is a view showing the configuration of a general iris recognition system.

2 is a diagram illustrating a configuration of multiple lighting devices in a general iris recognition system.

3 is a flow chart illustrating a method for automatically adjusting the focus using multiple lights of the iris recognition system according to the present invention.

<Description of Symbols for Main Parts of Drawings>

201 --- Distance measuring sensor 202 --- Distance measuring part

203 --- Distance Processing Unit 204 --- Camera Motion Control Unit

205 --- Camera 206 --- Image Processing Unit

207 --- Lighting Controls 208, 209 --- Lighting

In order to achieve the above object, the automatic focusing method using multiple lights of the iris recognition system according to the present invention,

Selecting and lighting one of the two lights;

Performing AE, AF, and AZ when the one light is turned on;

Extracting an iris image when the AE, AF, and AZ are performed;

After extracting the image, lighting the lighting at another position;

Re-extracting the iris image when the illumination of the other position is turned on;

Attempting iris recognition with the first extracted image;

Determining whether iris recognition is performed using the extracted first iris image;

If the recognition is rejected in the determining whether the recognition, characterized in that it comprises the step of attempting the iris recognition with the second extracted image.

According to the present invention, in particular, in performing iris recognition using a plurality of lights in order to avoid reflection due to wearing of the user's glasses, iris recognition is more quickly by omitting the repetitive focus automatic adjustment process according to the position of the lights. Can be done.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

3 is a flowchart illustrating a method for automatically adjusting focus using multiple lights of an iris recognition system according to an embodiment of the present invention with reference to FIGS. 1 and 2. As shown here, the iris registration method using multiple illumination of the iris recognition system, a user approaches to register the iris image to the iris recognition system, the eye to the optical axis of the camera 205 through the optical window 101 When positioned, the lighting control unit 207 turns on one of the lighting devices 208 having two lights of different positions to illuminate the user's iris (S301).

Subsequently, when one of the lights is turned on (208), AE (Auto Exposure), AF (AutoFocus), and AZ (Auto Zoom) are performed (S302). Looking at the process of performing each of the AE (Auto Exposure), AF (Auto Focus), AZ (Auto Zoom), the AE (Auto Exposure), the distance measuring unit 202 is set constant using the distance measuring sensor 201 The distance between the camera 205 and the user is measured every time, and continuous distance information is output. The distance processor determines the operating characteristics of the user using the distance information.

In other words, by measuring the user's operating speed based on continuous distance information, if the speed is positive, it is determined that it is approaching, if it is negative, it is determined that it is moving away, and if the absolute speed is within the given allowable value, it is stopped. I think that.

In addition, the AZ (Auto Zoom), when the user is stationary by using the information such as the distance, speed, acceleration, etc. provided from the distance processing unit 203 in the camera operation control unit 204, the operation of the camera 205 is stopped. To control. At this time, even when the user's motion is not stabilized, the time required for focusing is reduced by estimating a position where the user stops in advance and driving the lens of the camera 205 to the position.

When the user's motion is stabilized in this way, the camera's motion control unit 204 adjusts the zoom and focus of the camera based on the measured distance value. At this time, the user continues to move to some extent, and the measured distance value is not the distance to the real eye, so there is some measurement error. Thus, fine adjustment is performed.

In addition, AF (Auto Focus) analyzes the iris images continuously input from the image processing unit 206 in the camera operation control unit 206 to obtain a degree of focus, and zooms in until the degree of focus is suitable for performing confirmation. And continues to track in the direction of maximum value while moving the focus lens.

Thereafter, when the above-described AE (Auto Exposure), AF (Auto Focus), and AZ (Auto Zoom) are performed, the step of extracting the first iris image is performed (S303).

After extracting the first iris image, the lighting controller 207 turns on the lighting 209 at another position (S304).

Subsequently, when the lighting 209 at the other position is turned on, the second iris image is extracted again by the camera 205 (S305). In this case, after the lighting is turned on, instead of performing AE (Auto Exposure), AF (Auto Focus), and AZ (Auto Zoom) again, the state set when extracting the first iris image is left as it is, and only the illumination is changed. The second iris image is extracted.

After extracting the second iris image, an iris recognition is performed using the first extracted iris image (S306). Subsequently, it is determined whether iris recognition is performed using the extracted first iris image (S307).

However, if the recognition of the iris is rejected due to reflection due to the wearing of the user's glasses or the like in step S307, the iris recognition is attempted with the second extracted iris image (S308).

Therefore, in the iris recognition system having a plurality of illuminations, the iris image is changed by changing only the position of the illumination without performing the AE (Auto Exposure), AF (Auto Focus), and AZ (Auto Zoom) in the same manner as described above. By extracting, iris recognition can be performed more quickly.

Although the present invention has been described with reference to the embodiments illustrated in the drawings, this is merely exemplary, and it will be understood by those skilled in the art that various modifications and equivalent other embodiments are possible. Therefore, the true technical protection scope of the present invention will be defined by the technical spirit of the appended claims.

As described above, the method for automatically adjusting the focus using multiple illuminations of the iris recognition system according to the present invention, in particular, uses plural lights to avoid reflection due to wearing of the user's glasses. Iris recognition can be performed faster by omitting the repetitive focusing adjustment process according to the position.

Claims (2)

Selecting and lighting one of the two lights; Performing AE, AF, and AZ when the one light is turned on; Extracting an iris image when the AE, AF, and AZ are performed; After extracting the image, lighting the lighting at another position; Re-extracting the iris image when the illumination of the other position is turned on; Attempting iris recognition with the first extracted image; Determining whether iris recognition is performed using the extracted first iris image; And if the recognition is denied in the recognition step, recognizing the iris with the second extracted image. The method of claim 1, The illumination is provided with a predetermined number or more, only by changing the position of the illumination light, the AE, AF, AZ is the automatic focusing method using the multiple illumination of the iris recognition system, characterized in that for extracting the iris image in the first adjusted state .