KR102166333B1 - Method and apparatus for processing palm print image - Google Patents

Abstract

Displaying hand-shaped guide information, when an image is input, determining whether a hand is located in the guide information based on a signal pattern in a predetermined area of the guide information; And capturing an input image according to a result of the determination, and a terminal for the same.

Description

Long-print image processing method and terminal therefor TECHNICAL FIELD [Method and apparatus for processing palm print image]

The present invention relates to a palm print image processing method and a terminal therefor, and more particularly, to a palm print image processing method for acquiring and processing a palm print image using guide information, and a terminal therefor.

Typically, palm print recognition systems require high-resolution palm print images to obtain a high recognition rate. Therefore, in the conventional palm print recognition system, in order to obtain a consistent high-resolution palm print image, a method of inserting a finger between fixed rod-shaped columns and scanning was used, or a method of applying ink to the palm of the palm as if obtaining a fingerprint was used. .

However, in the conventional palm print recognition system, it is difficult to acquire a palm print image in real time from a portable terminal such as a mobile device when a palm print is scanned or inked. In addition, long-printed images using a camera built into a mobile device are acquired in a non-contact manner with the palm being photographed at a distance from the mobile phone without a separate fixing device. Therefore, in the conventional palm print recognition system, different images can be acquired from the same hand according to the user's hand posture or the distance and angle between the camera and the hand when taking an image, and thus, consistent features when extracting features for palm print recognition Cannot be obtained, which leads to a decline in the performance of mobile palm print recognition.

An object of the present invention is to provide a palm print image processing method for acquiring and processing a palm print image using a palm-shaped guide screen, and a terminal for the same.

A method for processing a long print image according to an embodiment of the present invention for achieving the above tasks includes the steps of displaying hand-shaped guide information; Determining whether a hand is located on the guide information based on a signal pattern in a predetermined area of the guide information when an image is input; And capturing the input image according to the determination result.

The determining whether a hand is located in the guide information may include: setting an area from which an image signal is to be extracted from the guide information; Analyzing a signal pattern in the set region; And determining whether a hand is located in the guide information based on the analyzed signal pattern.

The process of setting the region may include setting a region of interest of the finger image or a line segment of the finger image in the guide information.

The process of setting the line segment of the finger image is characterized in that the line segments are set above and below the goal point of the predetermined finger, and the line segments are symmetrically set with respect to the right and left hands.

The process of analyzing the signal pattern may include comparing the image signal pattern of the first region of the guide information with the image signal pattern of the second region of the guide information.

The process of analyzing the signal pattern may include calculating a difference between an average value of all YCbCr of the first region and a YCbCr value of a pixel corresponding to the second region of the guide information.

Determining whether the hand is located in the guide information includes comparing the image signal pattern of the first region of the guide information with the image signal pattern of the second region of the guide information to determine whether the foreground corresponds to the hand or the background other than the hand. It is characterized by distinguishing cognition.

The step of determining whether the hand is positioned on the guide information may include analyzing a signal pattern for the input image after the focus of the camera is adjusted.

And checking whether a hand exists in the input image based on the color information of the predetermined area of the guide information.

The step of determining whether a hand is present in the input image may include: setting a region of interest in the guide information; Determining whether an average pixel value in the region of interest is included in a preset primary boundary; Obtaining a ratio of a pixel included in a predetermined secondary boundary among all pixels in the set region of interest; And determining whether a hand exists in the input image based on the pixel ratio.

A method for processing a long print image according to another embodiment of the present invention for achieving the above tasks includes: displaying hand-shaped guide information; Checking whether a hand exists in the input image based on color information in a predetermined area of the guide information; Determining whether a hand is located in the guide information based on a pattern of an image signal in a predetermined area of the guide information according to the confirmation result; And capturing the input image according to the determination result.

A long print image processing apparatus according to an embodiment of the present invention for achieving the above tasks includes: a guide information generator for generating hand-shaped guide information; A color analysis unit determining whether a hand is included in the input image based on color information in a predetermined area of the guide information; A signal pattern analysis unit determining whether a hand is positioned in the guide information based on a pattern of an image signal in a predetermined area of the guide information; And an image capture unit for capturing an input image signal according to a determination result of the color analysis unit and the signal pattern analysis unit.

A terminal according to an embodiment of the present invention for achieving the above tasks includes a camera unit for photographing an image; An image processing unit that displays hand-shaped guide information and, when an image is input from the camera unit, analyzes an image signal in a predetermined area of the guide information to determine whether a hand is located in the guide information; And a display unit that displays the guide information and an image captured by the camera unit.

The image processing unit may include a guide information generating unit generating hand-shaped guide information; An image input unit for inputting an image captured by the camera; A color analysis unit determining whether a hand is included in the input image based on color information in a predetermined area of the guide information; A signal pattern analysis unit determining whether a hand is positioned in the guide information based on a pattern of an image signal in a predetermined area of the guide information; And an image capture unit for capturing an input image signal according to a determination result of the color analysis unit and the signal pattern analysis unit.

1 is a block diagram of a terminal according to an embodiment of the present invention.
2 is a detailed block diagram of the image processing unit of FIG. 1.
3 is a flowchart illustrating a method of processing a long print image according to an embodiment of the present invention.
4 is a flowchart illustrating a method of processing a long print image according to another exemplary embodiment of the present invention.
5A and 5B illustrate left and right hand guide information according to an embodiment of the present invention.
6 is a flowchart illustrating color signal analysis in a setting area of guide information according to an embodiment of the present invention.
7 is a flowchart illustrating signal pattern analysis according to an embodiment of the present invention.
8 illustrates an example of setting an ROI for analyzing a color signal according to an embodiment of the present invention.
9 is a diagram illustrating an example of setting right hand segments for verifying suitability of a long-print image according to an embodiment of the present invention.
10 is a diagram illustrating an example of setting a skin color distribution in a YCbCr color space used to determine whether a hand exists in a guide image according to an embodiment of the present invention.
11 illustrates an example of a signal pattern of a line segment located above a goal point for checking a long print image according to an embodiment of the present invention.
12 illustrates an example of a signal pattern of a line segment located below a goal point for checking a long print image according to an embodiment of the present invention.

Since the present invention can apply various transformations and have various embodiments, specific embodiments are illustrated in the drawings and will be described in detail in the detailed description. However, this is not intended to limit the present invention to a specific embodiment, it should be understood to include all conversions, equivalents, or substitutes included in the spirit and scope of the present invention. In describing the present invention, when it is determined that a detailed description of a related known technology may obscure the subject matter of the present invention, a detailed description thereof will be omitted.

Terms such as first and second may be used to describe various components, but the components should not be limited by terms. The terms are only used for the purpose of distinguishing one component from another component.

The terms used in the present application are used only to describe specific embodiments, and are not intended to limit the present invention. The terms used in the present application have selected general terms that are currently widely used as possible while considering the functions of the present invention, but this may vary according to the intention of a technician working in the field, precedents, or the emergence of new technologies. In addition, in certain cases, there are terms arbitrarily selected by the applicant, and in this case, the meaning of the terms will be described in detail in the description of the corresponding invention. Therefore, the terms used in the present invention should be defined based on the meaning of the term and the overall contents of the present invention, not a simple name of the term.

Singular expressions include plural expressions unless the context clearly indicates otherwise. In the present application, terms such as "comprise" or "have" are intended to designate the presence of features, numbers, steps, actions, components, parts, or combinations thereof described in the specification, but one or more other features. It is to be understood that the presence or addition of elements or numbers, steps, actions, components, parts, or combinations thereof, does not preclude in advance.

1 is a block diagram of a terminal according to an embodiment of the present invention.

The terminal of FIG. 1 includes a camera unit 110, an image processing unit 120, a control unit 130, a display unit 140, a memory 150, a communication interface unit 160, a key input unit 170, and an audio processing unit 180. Includes.

The camera unit 110 captures an image, and may obtain an image frame such as a still image or a video through an image sensor in a video call mode or a photographing mode. In this case, the image captured through the image sensor may be processed into a desired signal through the image processing unit 120.

The image frame processed by the camera unit 120 may be stored in the memory 150 or transmitted to the outside through the communication interface unit 160.

When the palm print recognition function starts, the image processing unit 120 displays guide information in the shape of a palm on the display unit 140, and when a captured image is input from the camera unit 120, the image signal in a predetermined area of the guide information is analyzed. It verifies whether the input image is suitable for long print recognition.

The controller 130 controls each block, and in particular, controls the focus of the lens of the camera unit 110 or inputs an image signal of a new frame according to focus adjustment to the image processing unit 120.

The display unit 140 displays a frame image or various information processed by the image processing unit 120 on a screen, and displays user data output from the control unit 130. In particular, the display unit 140 displays guide information and an image captured by the camera unit 110.

The memory 150 stores commands executed by the controller 130 or temporarily stores various information data. The memory 150 is a flash memory type, a hard disk type, a multimedia card micro type, a card type memory (for example, SD or XD memory), and RAM. (RAM, Random Access Memory) SRAM (Static Random Access Memory), ROM (ROM, Read-Only Memory), EEPROM (Electrically Erasable Programmable Read-Only Memory), PROM (Programmable Read-Only Memory), magnetic memory, magnetic disk And at least one type of storage medium among optical disks.

The communication interface unit 160 transmits and receives a radio signal with at least one of a base station, an external terminal, and a server on a mobile communication network. Here, the wireless signal may include a voice call signal, a video call signal, or various types of data according to transmission/reception of text/multimedia messages.

The key input unit 170 receives a control command from a user through a touch screen or an input key.

The audio processing unit 180 reproduces an audio signal generated from the controller 130 through a speaker or inputs an audio signal generated from a microphone to the controller 130.

2 is a detailed block diagram of the image processing unit 120 of FIG. 1.

The image processing unit 120 of FIG. 2 includes a guide information generation unit 210, an image input unit 220, a color analysis unit 220, a signal pattern analysis unit 240, and an image capture unit 250.

The guide information generation unit 210 generates guide information in the shape of a palm for acquiring a long-print image on the screen.

The image input unit 220 inputs an image captured by the camera unit 110.

The color analysis unit 230 analyzes whether a hand is included in the input image based on color information in a predetermined area of the guide information.

The signal pattern analysis unit 240 analyzes whether a hand is positioned in the guide information based on a pattern of an image signal in a predetermined area of the guide information.

The image capture unit 250 captures an input image signal according to the analysis results of the color analysis unit 230 and the signal pattern analysis unit 240.

3 is a flowchart illustrating a method of processing a long print image according to an embodiment of the present invention.

This method begins at step 310.

In step 320, when the palm print recognition function is started, the terminal displays guide information in the shape of the palm of a hand for obtaining a palm print image on the screen.

In one embodiment, the terminal provides a guide screen in the shape of a palm on the screen so that a user can conveniently input a palm print image while maintaining a relatively same hand posture and a distance to the camera. The terminal displays the guide information in the shape of the bottom of the hand so that the long-print area used for recognition is obtained as large as possible within the range in which the camera focuses. In this case, the guide information in the shape of the bottom of the hand is displayed in a clockwise direction as shown in FIG. 5A for the left hand and in a counterclockwise direction as shown in FIG. 5B for the right hand in consideration of the user's convenience. The palmar region is extracted from the lower part parallel to the goal point between the index finger and middle finger and the goal point between the ring finger and the hand finger. Therefore, in order to induce the hand to be matched to the position of the two goal points, the terminal has the goal points (502a, 502b) between the index and middle fingers, the goal points (503a, 503b) between the middle and ring fingers, and the goal points (504a, 504b) between the ring finger and the holding finger. Draw with a solid line. In addition, the terminal draws the palm borders 501a and 501b between the thumb and the index finger and the lower palm borders 505a and 505b with a dotted line so that the user's hand is naturally guided based on the three goal points mentioned above. In expressing the hand-shaped guide, the guide information in the obliquely inclined form including the above two goal points enables the acquisition of certain palm prints, thereby ensuring a high level of palm print recognition performance and acting as an important factor in enhancing user convenience. do.

In step 330, the terminal inputs an image captured by the camera.

In step 340, when an image is input, the terminal determines whether a hand is located in the guide information by analyzing a signal pattern of a preset area of the guide information, for example, a preset area or line segment in the finger image. If it is determined that the hand is located in the guide information, the terminal passes (PASS) to the next step 350, otherwise (NON-PASS) performs step 330.

In step 350, if it is determined that the hand is located in the guide information, the terminal determines and captures the input image as an image suitable for recognition.

This method ends at step 360.

Eventually, the terminal uses the captured image confirmed to be suitable for authentication for palm print recognition.

4 is a flowchart illustrating a method of processing a long print image according to another exemplary embodiment of the present invention.

The method begins at step 405.

In step 410, when the palm print recognition function starts, the terminal displays guide information in the shape of a palm for acquiring a palm print image on the screen.

In step 415, the terminal inputs an image captured by the camera.

In step 420, the terminal checks whether focus is being adjusted by the camera. If it is checked that focus is being adjusted, the terminal continuously inputs images of new frames.

In step 425, if it is checked that focus is not being adjusted, the terminal determines whether a hand is included in the input image by analyzing color information of a specific area of the guide information, for example, a preset area of the finger image of the guide information. If the terminal checks whether the input image includes a hand, the terminal passes (PASS) to the next step 430, otherwise (NON-PASS) performs step 415.

Whether the hand is included in the input image is not limited to the method of analyzing the above-mentioned color information, and the hand shape or texture information is used by modeling the hand such as AAM (Active appearance model) and ASM (Active shape model). It is also possible to use a separate sensor that senses the temperature of the human body, such as methods of doing things or a body temperature sensor.

In step 430, if it is not confirmed that a hand exists in the input image, the terminal receives a new image and processes the image again from step 415. However, if it is determined that the hand is present in the input image, the terminal determines whether the hand is located in the guide information by analyzing a signal pattern of a preset area of the guide information, for example, a preset area or line segment in the finger image. If the terminal determines that the hand is located in the guide information, it passes (PASS) to the next step 435, otherwise (NON-PASS) determines that the hand image is not suitable for palm print recognition, and inputs a new frame image again in step 415. Receive.

In step 435, if the terminal determines that the hand is located in the guide information, it determines that the hand image is suitable for recognition and checks whether the focus adjustment has been completed.

In step 440, if it is checked that focus adjustment has not been completed, the terminal starts focus adjustment and inputs an image of a frame in step 415.

In step 445, if it is checked that the focus adjustment has been completed, the terminal determines and captures the input image as an image suitable for recognition.

This method ends at step 450.

6 is a flowchart illustrating color signal analysis in a setting area of guide information of FIG. 4.

The method begins at step 610.

In step 620, the terminal sets a central ROI in the guide information for color signal analysis.

As an example, as shown in FIG. 8, the region of interest (ROI) for color analysis is a line segment 803 connecting the goal point 801 between the index finger and the middle finger and the goal point 802 between the ring finger and the hand finger. When the length of) is L, it is defined as a region 804 that is appropriately separated from it. As an example, the central region of interest is a rectangular region 804 with a horizontal length L and a vertical length of 0.3L vertically separated by 0.3L.

In step 630, the terminal determines whether the average pixel value in the central ROI is included in a preset primary boundary. As an example, the terminal measures the average Cb and Cr values in a rectangular area, and determines whether these values are included in a primary boundary corresponding to a range of Cb and Cr that can have a skin color. The range of Cb and Cr corresponding to the color information used at this time is set large to accommodate most hand images through learning data of various races and ages.

In step 640, the terminal determines a pixel ratio included in the predetermined secondary boundary among all pixels in the central ROI. As an example, the terminal sets the secondary boundary corresponding to the range of the maximum Cb and Cr that a single hand image can have through the training data, and the pixels included in the secondary boundary among all pixels in the central ROI are The ratio is measured to determine whether a hand exists in the image. Referring to FIG. 10, the x coordinate is in the Cr range, the y-axis is in the Cb range, 101 is the first boundary, 102 is the second boundary, and 103 is the distribution of each pixel in the central region of interest.

In step 650, the terminal determines whether a hand exists in the input image based on the determined pixel ratio.

The method ends at step 660.

7 is a flowchart illustrating signal pattern analysis of FIGS. 3 and 4.

The method begins at step 710.

In step 720, the terminal sets a finger region or a finger line segment from which an image signal is to be extracted from the guide information. As an example, the area or line segment of the finger is set so as to check whether or not each bone point of the hand being actually photographed has properly entered the vicinity of each goal point of the above-mentioned guide. That is, the positions of the line segments to extract the signal of the image are above the goal points 502a and 502b between the index finger and middle finger of the guide, and the goal points 504a and 504b between the ring finger and the hand finger as shown in FIGS. 5A and 5B. , Is set below. As shown in Fig. 9, when the length of the line segment 903 connecting the goal point 901 between the index finger and the middle finger and the goal point 902 between the ring finger and the hand finger is L, an appropriate ratio thereof, For example, the position of a line segment of 0.44L length is set at the top 904 and the bottom 905 with the center of the goal 901 between the index finger and the middle finger, and the upper 906 also with the goal 902 between the ring and the hand finger. ) And below (907). In the case of the left hand, the positions of the line segments for signal extraction are symmetrically set to the positions of the line segments set from FIG. 9 in a shape as shown in FIG. 5A.

Referring to FIG. 9, if a hand image is acquired according to the guide shape, a 1D image signal will show a hand -> background -> hand pattern at the line segments 904 and 906 above the set goal point, and In the line segments 905 and 907, all hand patterns will be shown.

In step 730, the terminal analyzes the image signal pattern in a preset line segment or region of the finger. The terminal analyzes the signal patterns of the two line segment pairs around the above-mentioned index and ring finger bone points to verify whether a long-print image suitable for recognition has been acquired. As an example, in order to determine the signal pattern in the line segment, the terminal uses the difference in pattern information between the central ROI, which is a skin color area of the hand, and a point located on the line segment. The signal pattern value at one point on the line segment is obtained by applying Equation 1 to the difference between the average YCbCr value of the entire center ROI region and the YCbCr value of the pixel corresponding to this point.

Here, Y _ROI , Cb _ROI , Cr _ROI are the average YCbCr values of the central ROI region, Y _iN , Cb _iN , Cr _iN are the YCbCr values at a point on the line segment, WI is the Y value weight, and Dist is the signal pattern. Indicate the difference value.

When the hand image is acquired according to the shape of the guide, the pattern value of the line segment located at the tops 904 and 906 of the above-mentioned goal points may be represented by a signal waveform as shown in FIG. 11. Referring to FIG. 11, the center has a large distance corresponding to the background, while both ends of the line segment have a small distance corresponding to the skin foreground (1101). In this case, the x-axis of FIG. 11 is the line segment length (L), the y-axis is the signal pattern difference value, 1103 corresponds to the goal point, and 1102 corresponds to the reference value. The signal waveform shown in FIG. 11 indicates that the line segment is divided into a hand region, a background region, and a hand region. On the other hand, the line segment located at the bottoms 905 and 907 of the goal point of FIG. 9 has small values 1201 less than the reference value 1202 since the entire line segment pattern signal corresponds to the hand region as shown in FIG. 12.

In step 740, the terminal determines whether a hand is located in the guide information based on the analyzed image signal pattern. As shown in FIG. 11, if the number of intersection points with the threshold value in the upper line segment of the goal point and the number of intersection points with the threshold value in the lower line segment position of the goal point satisfy both conditions, the terminal is suitable for recognizing the guide information. It is determined that an image has been input.

In the above embodiment, in order to determine whether the hand image is acquired in conformity with the guide shape, a line segment from the finger is analyzed, but not limited to the line segment, pixels corresponding to a preset region of interest in the finger may be analyzed.

In the aspect of cost and security, the palm print image processing method according to an embodiment of the present invention can perform palm print recognition only in a necessary part of the guide screen using a camera mounted on a mobile device without using a separate dedicated sensor. It can bring many advantages to the user, and it is also possible to increase the user's convenience by automatically evaluating the quality of the image and obtaining a long-length image.

One or more programs including instructions for performing a method of implementing a method for processing a long-print image according to embodiments of the present invention with a computer may be recorded as computer-readable codes on a computer-readable recording medium. The computer-readable recording medium includes all types of storage devices storing data that can be read by a computer system. Examples of computer-readable recording media include ROM, RAM, CD-ROM, magnetic tape, floppy disk, and optical data storage. In addition, the computer-readable recording medium can be distributed over a network-connected computer system, and stored and executed as computer-readable codes in a distributed manner.

So far, the present invention has been looked at around its preferred embodiments. Those of ordinary skill in the art to which the present invention pertains will be able to understand that the present invention can be implemented in a modified form without departing from the essential characteristics of the present invention. Therefore, the disclosed embodiments should be considered from an illustrative point of view rather than a limiting point of view. The scope of the present invention is shown in the claims rather than the foregoing description, and all differences within the scope equivalent thereto should be construed as being included in the present invention.

Claims (15)

Displaying hand-shaped guide information;
Determining whether a hand is present and a hand is located in the guide information based on color information and an image signal pattern in a predetermined area of the guide information when an image is input; And
And capturing the input image according to the determination result,
The step of determining whether the hand is present,
Setting a region of interest in the guide information;
Determining whether an average pixel value in the region of interest is included in a preset primary boundary;
Obtaining a pixel ratio included in a predetermined secondary boundary among all pixels in the set region of interest; And
And determining whether a hand exists in the input image based on the pixel ratio. The method of claim 1, wherein determining whether a hand is located on the guide information comprises:
Setting an area from which an image signal is to be extracted from the guide information;
Analyzing a signal pattern in the set region; And
And determining whether a hand is located in the guide information based on the analyzed signal pattern. The method of claim 2, wherein the setting of the region comprises setting an ROI of the finger image or a line segment of the finger image in the guide information. The long-print image of claim 3, wherein the setting of the line segment of the finger image comprises setting the line segment above and below the goal point of the predetermined finger, and setting the line segment symmetrically with respect to the right hand and the left hand. Processing method. The method of claim 2, wherein the analyzing the signal pattern comprises:
And comparing the image signal pattern of the first region of the guide information and the image signal pattern of the second region of the guide information. The method of claim 2, wherein the analyzing the signal pattern comprises:
And calculating a difference between an average value of all YCbCr in the first region and YCbCr values of pixels corresponding to the second region of the guide information. The foreground of the hand according to claim 2, wherein determining whether the hand is located in the guide information comprises comparing an image signal pattern of a first area of the guide information with an image signal pattern of a second area of the guide information. A method of processing a long text image, characterized in that it distinguishes whether it is a background or not a hand. The method of claim 2, wherein the determining whether the hand is located in the guide information comprises analyzing a signal pattern for the input image after the focus of the camera is adjusted. The method of claim 1, further comprising checking whether a hand exists in the input image based on color information of a predetermined area of the guide information. delete Displaying hand-shaped guide information;
Checking whether a hand exists in the input image based on color information in a predetermined area of the guide information;
Determining whether a hand is located in the guide information based on a pattern of an image signal in a predetermined area of the guide information according to the confirmation result; And
And capturing the input image according to the determination result,
Checking whether the hand is present,
Setting a region of interest in the guide information;
Determining whether an average pixel value in the region of interest is included in a preset primary boundary;
Obtaining a pixel ratio included in a predetermined secondary boundary among all pixels in the ROI; And
And determining whether a hand exists in the input image based on the pixel ratio. A guide information generator for generating hand-shaped guide information;
A color analysis unit determining whether a hand is included in the input image based on color information in a predetermined area of the guide information;
A signal pattern analysis unit determining whether a hand is positioned in the guide information based on a pattern of an image signal in a predetermined area of the guide information; And
An image capture unit for capturing an input image signal according to a determination result of the color analysis unit and the signal pattern analysis unit,
The color analysis unit,
Set a region of interest in the guide information,
It is determined whether the average pixel value in the region of interest is included in the preset primary boundary,
And obtaining a pixel ratio included in a predetermined secondary boundary among all the pixels in the region of interest, and determining whether a hand exists in the input image based on the pixel ratio. A camera unit for photographing an image;
An image processing unit that displays hand-shaped guide information and, when an image is input from the camera unit, analyzes an image signal in a predetermined area of the guide information to determine whether a hand is located in the guide information; And
And a display unit for displaying the guide information and the image captured by the camera unit,
The image processing unit,
A guide information generator for generating hand-shaped guide information;
An image input unit for inputting an image captured by the camera;
A color analysis unit determining whether a hand is included in the input image based on color information in a predetermined area of the guide information;
A signal pattern analysis unit determining whether a hand is positioned in the guide information based on a pattern of an image signal in a predetermined area of the guide information; And
And an image capture unit for capturing an input image signal according to a determination result of the color analysis unit and the signal pattern analysis unit,
The color analysis unit,
Set a region of interest in the guide information,
It is determined whether the average pixel value in the region of interest is included in the preset primary boundary,
And obtaining a pixel ratio included in a predetermined secondary boundary among all pixels in the region of interest, and determining whether a hand exists in the input image based on the pixel ratio.
delete A computer-readable recording medium in which a program for implementing the method of any one of claims 1 to 9 and 11 is recorded.

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