KR100619680B1 - The method for correcting motion blurring of an iris recognition system - Google Patents

Abstract

The present invention relates to a method for correcting motion blur of an iris recognition system. In the related art, a camera for photographing an iris image adopts a parallel scan type CD camera to move a human, or an odd field and an even field. Due to the time difference (1/60) of the (even field), blurring occurs in the image, and thus there is a problem of misrecognition. Accordingly, the present invention provides a first step of receiving an iris image through a camera, a second step of reconstructing the iris image input into the iris image consisting of only an odd field and an even field, and a center of the reconstructed iris image. A third step of finding coordinates and finding a difference between the center coordinates, a fourth step of correcting the center position of the iris image by the difference of the center coordinates obtained above, and performing iris recognition using the corrected iris image In the fifth step to correct the iris image to increase the recognition rate.

Description

Motion blur correction method of iris recognition system {THE METHOD FOR CORRECTING MOTION BLURRING OF AN IRIS RECOGNITION SYSTEM}

1 is a block diagram of a conventional iris recognition system.

Figure 2 is an operation flow diagram for the motion blur correction method of the present invention iris recognition system.

Figure 3 is an illustration of the iris image captured by a camera in a progressive scan before applying the present invention.

4 is an exemplary view showing an iris image after applying the present invention.

***** Explanation of symbols for the main parts of the drawing *****

10: distance measuring sensor 20: optical imager driver

30: external indicator 40: lighting device

50: Engineering Windows 60: Cold Mirrors

70: camera 80: frame grabber

90: controller

According to the present invention, an iris recognition system employing an interlaced scan CCD camera is used to correct motion blurring caused by a user's movement to minimize recognition errors. The present invention relates to a motion blur correction method of a recognition system. In particular, a motion of an iris recognition system to prevent misunderstanding due to blur caused by a time difference between an odd field and an even field when scanning an iris image. It relates to a blurring correction method.

Recently, biological features have been used for identification in automatic access control systems and automatic commerce systems using the Internet.

Biological features include fingerprints, voices, retinas, faces, and irises, but they vary from person to person. Especially, the identification of using iris that has less risk of imitation and does not change well for a lifetime is attracting attention.

The iris is a thin film on the disc between the cornea of the eye and the lens, and is composed of muscles that control opening and closing of the pupil, and controls the amount of incident light and sharpens the image.

It is known that the human eye is formed until about 6 months of gestation, and at that time, a hole is opened in the part of the pupil, and a weight (주 = wrinkle) is generated outward from the opening (瞳) as a chaotic image. The growth of this weight usually stops after a few years of life, and does not change throughout life, forming a pattern of its own. This pattern is different for the right and left eyes of the same person and also for identical twins.

Therefore, the iris recognition uses the characteristics of the iris, and the individual pattern is identified by comparing the characteristic pattern of the iris captured by the video camera with image processing technology and comparing it with the iris data registered in advance.

1 is a block diagram of a conventional iris recognition system. As shown in FIG. 1, a distance measuring sensor 10 measuring a distance to a user using an infrared sensor, and notifying a user of whether the system is activated and recognized The external indicator 30, the illumination device 40 for adjusting the illuminance when shooting the iris image irrespective of the brightness of the surrounding, the optical window 50 for positioning the user's eyes, and the optical window 50 A cold mirror 60 passing through the infrared rays and blocking visible light, a camera 70 for capturing an iris image of the user transmitted to the cold mirror 60, and an iris photographed by the camera 70. A frame grabber 80 for processing an image for image analysis and a distance measurement value measured by the distance measuring sensor 10 are input to determine whether the user is within an operating range, and If it is determined to be within the stomach to automatically recognize the iris, and adjusts the light intensity of the control device 90, the operation of the external indicator 30 and the lighting device 40 in accordance with the control of the control device 90 It consists of an optical imager driver 20 for controlling.

Looking at the prior art configured as described above is as follows.

When the user approaches the iris recognition system, the distance measuring sensor 10 transmits the distance measurement value obtained by measuring the distance to the user through the optical imager driver 20 to the control device 90.

Accordingly, the control device 90 determines whether the received distance measurement value is within the operating range.

If it is determined that the user is within the operating range, the control device 90 outputs the optical imager control signal to the optical imager driver 20 to prepare for extraction of the iris image.

The optical imager driver 20 then sends an active signal to the external indicator 30 to inform the user that the system has been activated.

Therefore, when the user approaches the optical imager and places the eye on the optical axis of the camera 70 through the optical window 50, the cold mirror 60 passes the infrared rays and blocks the visible light. In addition, the cold mirror 60 marks the portion where the iris should be located so that the user can easily check whether his or her own eye is located on the optical axis of the camera 70.

At this time, the control device 90 receives the distance measurement value from the distance measurement sensor 10 to the user again, and calculates the zoom and focus values of the camera 70 by using the received distance measurement value. By controlling the zoom motor and the focus motor (not shown), the iris image can be controlled to capture an iris image having a desired magnification.

Thereafter, the control device 90 adjusts the intensity of the illumination device 40 through the optical imager driver 20 according to the distance measurement value, and then photographs the iris image through the camera 70.

When the iris image photographed by the camera 70 is provided to the frame grabber 80, the frame grabber 80 processes the signal in accordance with image analysis and provides it to the control device 90.

The control device 90 receiving the processed signal as described above informs the user whether the external indicator 30 is recognized through the optical imager driver 20.

However, in the prior art as described above, the camera for capturing the iris image adopts an AA scan CD camera so that an odd field and an even field may be used in a CD of the user's movement or a PD scan method. Due to the time difference (1/60) of the (even field), blurring occurs in the image, and thus there is a problem of misrecognition.

Therefore, an object of the present invention for solving the conventional problems as described above is to determine the central position of the blurred iris image due to the time difference between the odd field and the even field in the CD of the human movement The present invention provides a method for correcting motion blur of an iris recognition system.

Another object of the present invention is to provide a method for correcting motion blur of an iris recognition system to improve a recognition rate by correcting a blurred iris image.

The present invention for achieving the above object is a first step of receiving an iris image through a camera, a second step of reconstructing the input iris image into an iris image consisting of only the odd field and even field, respectively, A third step of finding the center coordinates of the iris image, and obtaining a difference of the center coordinates; a fourth step of correcting the center position of the iris image by the difference of the center coordinates obtained above; and using the corrected iris image The fifth step is to perform the iris recognition.

Hereinafter, with reference to the accompanying drawings in detail as follows.

FIG. 2 is a flowchart illustrating a motion blur correction method of the iris recognition system according to the present invention. As shown therein, a first step (S101) of receiving an iris image of 640 × 480 bytes through a camera and the first A second step (S102) of reconstructing an image by extracting only an odd field from an iris image received in the step and copying it to an even line, and an even field from an iris image received in the first step A third step (S103) of reconstructing another image by extracting the bay and copying it to an odd line; and a fourth step (S104) of obtaining the center coordinate 1 of the image reconstructed using only the odd field in the second step. ), A fifth step (S105) of obtaining the center coordinates 2 of the image reconstructed using only the even field in the third step, and a sixth step (S106) of obtaining the difference between the center coordinates obtained in the fourth and fifth steps, respectively. ), And a seventh step (S107) of adjusting the center position by moving the even lines of the even field in parallel by the difference of the center coordinates obtained in the sixth step with respect to the odd field, and the image corrected by adjusting the center position. Eighth step (S108) for performing the iris recognition by using.

When described in detail with respect to the operation and effect of the present invention made of each step as follows.

When the user approaches the iris recognition system, the distance measuring sensor 10 transmits the distance measurement value obtained by measuring the distance to the user through the optical imager driver 20 to the control device 90.

Accordingly, the control device 90 determines whether the received distance measurement value is within the operating range.

If it is determined that the user is within the operating range, the control device 90 outputs the optical imager control signal to the optical imager driver 20 to prepare for extraction of the iris image.

The optical imager driver 20 then sends an active signal to the external indicator 30 to inform the user that the system has been activated.

Therefore, when the user approaches the optical imager and places the eye on the optical axis of the camera 70 through the optical window 50, the controller 90 adjusts the intensity of the illumination device 40 according to the distance measurement value.

When the camera 70 captures an iris image having a size of 640 × 480 bytes and provides it to the frame grabber 80, the frame grabber 80 processes an odd field and an even field processed for image analysis. The iris image having a field) is transmitted to the controller 90.

Then, the control device 90 receives an iris image of 640 × 480 bytes as shown in FIG. 2 (S101).

The aud field and even field are extracted from the iris image received above.

Only the extracted aod field is used to reconstruct an iris image. That is, the odd field is copied to an even line again in an image having only the odd field, and a single image consisting of only the odd field is reconstructed (S102).

Similarly, the image having only the even field is copied again to the odd line to reconstruct one image including only the even field (S103).

After reconstructing the 640x480 bytes iris image consisting of only the aod field and the even field, the center coordinates of the iris image are found respectively (S104 and S105).

Here, the center coordinates of the iris image composed of only the odd fields are represented by central coordinates 1, and the center coordinates of the iris image composed only of the even fields are displayed as central coordinates 2.

In general, a distance of 1 cm is represented by 200 pixels in an image of 640 × 480 bytes, and 10 pixels are shifted by only 1 mm movement for 1/60 second.

Therefore, the difference between the center coordinate 1 and the center coordinate 2 obtained from the two images is calculated to correct the time difference (1/60 second) between the odd field and the even field and the movement of the person (S106).

In order to compensate for the difference in the center coordinates, the even lines of the even field are parallelly shifted by the difference of the center coordinates, and the even lines of the translated even field are moved to the odd field. Creates a new image by replacing the even lines of the composed image.

In the above, the new image is a corrected image correcting a human motion and a time difference between the odd field and the even field.

Put this corrected image as input to the function for iris recognition.

As a result, as shown in (a) (b) of FIG. 3, the iris image blurred by the CD camera of the bipolar scan method is corrected in consideration of a human motion and a time difference between the odd field and the even field. As a result, the recognition rate can be increased as shown in FIG.

As described in detail above, the present invention has the effect of improving the recognition rate by correcting the blurred iris image due to the time difference between the odd field and the even field in the CD of the human movement and the interrogative scan method.

Claims (2)

In the iris recognition method, a first step of receiving an iris image through a camera, a second step of reconstructing the input iris image into an iris image consisting of only an odd field and an even field, and a reconstructed iris image A third step of finding the center coordinates of each to find the difference between the center coordinates; a fourth step of correcting the center position of the iris image by the difference of the center coordinates obtained above; and using the corrected iris image Motion blur correction method of the iris recognition system, characterized in that consisting of a fifth step of performing. The method of claim 1, wherein the fourth step comprises moving the even field in parallel with the difference in the center coordinates based on the odd field.

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