KR101012596B1 - Rolled fingerprint registration/synthesis apparatus and method using a baseline - Google Patents

Abstract

PURPOSE: A rolled fingerprint registration/synthesis apparatus and a method thereof are provided to synthesis two rolled fingerprints using a baseline. CONSTITUTION: An offset value matched with a control point to a first rotation fingerprint frame is calculated(230). The first registration frame is generated by matching the second fingerprint frame to a first finger print frame. The control spot is moved as the offset value(240). A second baseline is established by connecting the moved control spot(250). A first synthesis frame and a first rolled finger print frame is synthesized using a second baseline(260).

Description

Rotation fingerprint matching / synthesis device and method using a baseline {ROLLED FINGERPRINT REGISTRATION / SYNTHESIS APPARATUS AND METHOD USING A BASELINE}

It relates to a technique for obtaining a fingerprint by registering and synthesizing a rotating fingerprint frame.

Recently, the demand for accuracy of personal authentication is increasing day by day with the spread of information exchange through the Internet. In order to meet these demands, the application of authentication methods through biometrics is being gradually expanded.

In general, an authentication method based on a fingerprint, an iris, a voice, an image, or an electronic signature is known as a biometric authentication method. In particular, the fingerprint recognition method is not only harmful to the human body in that it only touches the user's finger, and because of the advantage that it can provide inexpensive equipment with excellent convenience and simple structure, about 70% or more of the entire biometric market. It is the reality that occupies.

Fingerprint recognition systems are applied to small digital devices such as laptops, mobile phones, PDAs as well as network security systems related to electronic commerce.

Rotational fingerprint matching / synthesis methods using a baseline are widely used to accurately acquire fingerprints. Rotational fingerprint matching / synthesis method using a baseline means that when a finger touches and rotates, a rotational fingerprint frame is obtained every set time, a portion overlapped between the obtained rotational fingerprint frames is cut out, and finally one synthesized fingerprint is obtained. How to obtain.

However, a problem arises in that important fingerprint related information is distorted in the process of obtaining a fingerprint. Accordingly, researches on how to accurately acquire fingerprints without distorting important fingerprint-related information are actively conducted.

Disclosed are a rotation fingerprint matching / compositing device and method using a baseline that can obtain an accurate fingerprint by synthesizing a rotating fingerprint frame using a baseline set for synthesis.

A rotation fingerprint matching / synthesis method using a baseline according to an embodiment of the present invention divides a region in which a first foreground including a fingerprint of a first rotating fingerprint frame and a second foreground including a fingerprint of a second rotating fingerprint frame overlap. Setting a first reference line, wherein the first reference line may be set, setting at least one of the points included in the second foreground and above the first reference line as a control point, and matching the control point. Calculating a displacement value up to a point of the first rotating fingerprint frame; matching the second rotating fingerprint frame to the first rotating fingerprint frame based on the displacement value to generate a first matching frame; After moving the control point by the displacement value, connecting the moved control point to set a second reference line and the first using the second reference line The sum comprises the steps of synthesizing the frame and the first rotating frame fingerprint.

In the synthesizing step, the region including the center position of the first rotation fingerprint frame is synthesized by weighting the brightness value of the first rotation fingerprint frame based on the second reference line, and the center position of the first matching frame is synthesized. The including region may include synthesizing by weighting the brightness value of the first matching frame.

Here, the rotation fingerprint matching / synthesis method using the reference line may further include selecting a matching and synthesis target frame based on the center position value of the fingerprint included in the obtained rotation fingerprint frames.

The selecting of the matching and synthesizing frame may include extracting a central position value of the fingerprint included in the rotating fingerprint frames obtained after starting the matching and compositing, and selecting a first frame among the obtained rotating fingerprint frames. Selecting a matching and combining target frame, and selecting a rotating fingerprint frame having a central position value whose distance from the central position value of the first matching and combining target frame is greater than or equal to a threshold as a second matching / synthesizing target frame And selecting a rotating fingerprint frame having a center position value whose distance from the center position value of the second registration / synthesis target frame is greater than or equal to a threshold value as the third registration / synthesis target frame.

The setting of the first reference line may include setting a first reference line by connecting a point where the outline of the first foreground meets the outline of the second foreground.

The setting of the first reference line may include extracting a point where the outline of the first foreshore meets the outline of the second foreground and the extracted point while morphological erosion of the first foreground and the second foreground. Connecting to establish a first reference line.

The setting of the first reference line may include calculating a center position corresponding to the overlapping region and setting a straight line perpendicular to a horizontal axis passing through the center position as the first reference line.

The setting of the first reference line may include setting a straight line perpendicular to a line connecting the center position of the first foreground and the center position of the second foreground to the first reference line.

The setting of the first reference line may include extracting an ellipse using an ellipse fitting algorithm for the overlapping region, and setting a straight line passing through the long axis of the ellipse as the first reference line. Can be.

A rotation fingerprint matching / compositing device using a reference line according to an embodiment of the present invention includes a first fingerprint including a rotating fingerprint frame obtaining unit obtaining a first rotating fingerprint frame and a second rotating fingerprint frame and a fingerprint of the first rotating fingerprint frame. Set a first reference line for dividing the overlapping area of the second foreground including the fingerprint of the foreground and the second rotating fingerprint frame, and at least one of the points included in the second foreground, and located on the first reference line Set to a control point, calculate a displacement value up to a point of the first rotating fingerprint frame that matches the control point, and based on the displacement value, convert the second rotating fingerprint frame to the first rotating fingerprint frame. To generate a first matching frame, move the control point by the displacement value, and then connect the moved control point to a second device. Setting a line and using the second reference line comprises a first frame, and matching the matching / synthesis unit configured to synthesize the first rotating frame fingerprint.

Here, the matching / compositing unit synthesizes an area including the center position of the first rotating fingerprint frame based on the second reference line by weighting pixel brightness values of the first rotating fingerprint frame, and the center position of the first matching frame. The region including may be synthesized by weighting pixel brightness values of the first matching frame.

Here, the rotation fingerprint matching / compositing apparatus using the reference line may further include a selection unit for selecting a matching and synthesis target frame based on the center position value of the fingerprint included in the rotation fingerprint frames obtained after starting the matching and synthesis. have.

Here, the selection unit extracts a center position value of the fingerprint included in the rotation fingerprint frames obtained after starting the matching and synthesis, selects a first matching and synthesis target frame among the obtained rotation fingerprint frames, and Selecting a rotation fingerprint frame having a center position value whose distance from the center position value of the first registration and composition target frame is greater than or equal to the threshold value as the second registration / synthesis target frame, and the center position value of the second registration / synthesis target frame; The rotation fingerprint frame having the center position value whose distance from the threshold is greater than or equal to the threshold value may be selected as the third matching / synthesis target frame.

According to the disclosed subject matter, accurate fingerprints can be obtained by synthesizing two rotating fingerprint frames using a baseline.

1 is a block diagram illustrating a rotation fingerprint matching / synthesis device using a reference line according to an embodiment of the present invention.
2 is a flowchart illustrating a rotation fingerprint matching / synthesis method using a reference line according to an embodiment of the present invention.
3A to 3E are diagrams for describing a method of setting a first reference line in FIG. 2.
FIG. 4 is a diagram for specifically describing a matching and synthesis method of FIG. 2.
FIG. 5 is a diagram for describing a process of selecting a matching and synthesis target frame in FIG. 2.

Hereinafter, with reference to the accompanying drawings will be described in detail the specific contents for carrying out the invention.

1 is a block diagram illustrating a rotation fingerprint matching / synthesis device using a reference line according to an embodiment of the present invention.

Referring to FIG. 1, a rotation fingerprint matching / compositing device 100 using a reference line includes a rotation fingerprint frame obtaining unit 110, a selecting unit 120, and a matching / compositing unit 130.

The rotating fingerprint frame obtaining unit 110 may include an optical, ultrasonic or semiconductor sensor. That is, the rotating fingerprint frame obtaining unit 110 may obtain a fingerprint image of the user using the sensors. The rotating fingerprint frame obtaining unit 110 may obtain the rotating fingerprint frame every set time when the user's finger is touched and rotated. For example, the rotating fingerprint frame obtaining unit 110 obtains the rotating fingerprint frame through the sensor every 0.5 seconds. When the contact and rotation of the finger is terminated for two seconds, the total number of rotating fingerprint frames is four.

The selector 120 may select a matching and synthesis target frame among the rotation fingerprint frames obtained after the matching and synthesis is started. Here, the matching and synthesizing frame means a rotating fingerprint frame to be used for matching and synthesis. For example, the selector 120 extracts a central position value of the fingerprint included in the rotating fingerprint frames obtained after matching and synthesis are started. The selector 120 selects a first matching and synthesis target frame among the obtained rotation fingerprint frames. The selector 120 selects a rotating fingerprint frame having a center position value whose distance from the center position value of the first matching and combining target frame is greater than or equal to a threshold value as the second matching and combining target frame. The selector 120 selects a rotation fingerprint frame having a center position value whose distance from the center position value of the second matching and combining frame is greater than or equal to the threshold value as the third matching and combining target frame. By repeating such a process, the selector 120 may select a matching and synthesis target frame. The matching / combining unit 130 may match and synthesize only the matching and compositing frame. A detailed description thereof will be described later with reference to FIG. 5.

The selector 120 may calculate the center positions of the fingerprints included in the rotated fingerprint frames obtained through the rotated fingerprint frame acquirer 110 in the following manner.

For example, the selector 120 extracts a foreground including a fingerprint and a background including no fingerprint from the rotating fingerprint frame. The selector 120 may smooth the rotating fingerprint frame and extract the foreground when the pixel brightness value is smaller than the set threshold. In other words, the black part is extracted to the foreground. On the other hand, the selector 120 may extract the background when the pixel brightness value is greater than the set value. In other words, the white part is extracted as the background. Alternatively, the selector 120 divides the rotation fingerprint frame into a plurality of blocks and then calculates an intensity variance value of each block. Next, the selector 120 may extract the foreground and the background by using the brightness dispersion value. For example, the selector 120 extracts the foreground when the calculated dispersion value is smaller than the set threshold. On the other hand, the selector 120 extracts the background when the calculated dispersion value is larger than the set value. In addition to the above-described embodiment, the selector 120 may extract the foreground and the background by various methods.

The selector 120 calculates a center of mass for the extracted foreground and determines the calculated center of mass as the center position. Here, the center of mass may be calculated using Equation 1 below.

Where cx is the x coordinate of the center of mass, cy is the y coordinate of the center of mass, px is the x coordinate of the pixel of the rotating fingerprint frame, py is the y coordinate of the pixel of the rotating fingerprint frame, and w (px, py) Is the weight.

Here, w (px, py) = 1 if (px, py) is a point in the foreground, and w (px, py) = 0 if (px, py) is a point in the background.

In another example, the selector 120 calculates the center of mass using the numbers 1, 2, and 3, and determines the calculated center of mass as the center position. In this case, the selector 120 may not extract the foreground or the background from the rotating fingerprint frame.

Here, instead of numbers 2 and 3, various equations may be used that give higher weights to dark pixel values.

As another example, the selector 120 extracts an outline of the fingerprint included in the rotating fingerprint frame. The selection unit 120 may determine a point where the middle point of the left and right widths of the outline and the middle point of the top and bottom widths of the outline meet as a center position.

The selector 120 may calculate the center position by various methods in addition to the above-described embodiment.

The matching / combining unit 130 may match all of the obtained rotation fingerprint frames or match the matching and synthesis target frames.

The matching / combining unit 130 sets a first reference line for dividing an area where the first foreground including the fingerprint of the first rotating fingerprint frame and the second foreground including the fingerprint of the second rotating fingerprint frame overlap. The matching / combining unit 130 is included in the second foreground and sets at least one of the points existing on the first reference line as a control point. The matching / combining unit 130 calculates a displacement value up to a point of the first rotating fingerprint frame that matches the control point. The matching / combining unit 130 generates a first matching frame by matching the second rotating fingerprint frame to the first rotating fingerprint frame based on the displacement value. The matching / combining unit 130 sets the second reference line by connecting the moved control point after moving the control point by the displacement value.

For example, the matching / combining unit 130 may set the first reference line by connecting a point where the outline of the first foreground meets the outline of the second foreground.

For another example, the matching / compositing unit 130 extracts a point where the outline of the first foreground and the outline of the second foreground meet while morphological erosion of the first foreground and the second foreground. The first reference line can be set by connecting points.

As another example, the matching / compositing unit 130 calculates a center position value corresponding to an area where the first foreground and the second foreground overlap, and sets a straight line perpendicular to the horizontal line passing through the center position value as the first reference line. Can be.

As another example, the matching / compositing unit 130 may set a straight line perpendicular to a line connecting the center position of the first foreground and the center position of the second foreground as the first reference line.

In another example, the matching / compositing unit 130 extracts an ellipse using an ellipse fitting algorithm for an area where the first foreground and the second foreground overlap each other, and extracts a straight line passing through the long axis of the ellipse. Can be set as a baseline.

A detailed description of the method of setting the first reference line will be described later with reference to FIGS. 8A to 8E.

For example, the matching / compositing unit 130 extracts a foreground of the first rotating fingerprint frame and the second rotating fingerprint frame. The matching / combining unit 130 matches the first rotating fingerprint frame and the second rotating fingerprint frame, and then extracts an area where the first foreground and the second foreground overlap. The matching / combining unit 130 is included in the second foreground and sets at least one of the points existing on the first reference line as a control point. The matching / combining unit 130 calculates a matching score that scores the same or similarity between the control point and the specific point of the first rotating fingerprint frame, and matches the point having the largest matching value with the control point. Can be recognized as a point. The matching value may be calculated by comparing the pixel brightness value of the control point with a specific point of the first rotating fingerprint frame. Alternatively, the matching value may be calculated by comparing pixel brightness values of a block including the control point with a specific block of the first rotating fingerprint frame.

As another example, the matching / compositing unit 130 may calculate the displacement value based on the displacement value calculated based on another control point. For example, on the basis of the first control point, two points having the largest matching values are described, and the displacement values are 1 and 10, respectively. When the displacement value calculated based on the second control point is 2, the matching / compositing unit 130 may calculate the displacement value as 1 close to the displacement value calculated based on the second control point. By doing in this way, the error which a displacement value is calculated incorrectly can be reduced.

The matching / combining unit 130 matches the second rotating fingerprint frame to the first rotating fingerprint frame based on the calculated displacement value. For example, the matching / combining unit 130 may match the second rotating fingerprint frame to the first rotating fingerprint frame by moving all pixels of the second rotating fingerprint frame based on the calculated displacement value. In this case, the matching / synthesizing unit 130 may determine the moving value of the pixel by interpolating peripheral displacement values.

The matching / combining unit 130 may synthesize the first matching frame and the first rotating fingerprint frame using the second reference line.

The matching / combining unit 130 may perform a method of synthesizing the region existing on the left side and the method of synthesizing the region existing on the right side based on the second reference line.

For example, the matching / combining unit 150 may synthesize a region including the center position of the first rotating fingerprint frame based on the second reference line by weighting the pixel brightness value of the first rotating fingerprint frame. In addition, the matching / combining unit 150 may synthesize a region including the center position of the first matching frame by weighting a pixel brightness value of the first matching frame.

As another example, the matching / compositing unit 150 may include an area including a center position of the first rotating fingerprint frame based on the second reference line, wherein the matching / synthesizing unit 150 has a first brightness value among the pixel brightness values of the first rotating fingerprint frame and the first matching frame. The pixel brightness values of the first rotation frame and the first registration frame are combined to further weight the pixel brightness values, and the area including the center position of the first registration frame is the pixel brightness of the first registration frame among the pixel brightness values of the first rotation frame and the first registration frame. You can synthesize them by giving more weight to the values.

For example, the matching / synthesizing unit 130 includes a center position of the first rotational fingerprint frame with respect to the second reference line. It can be synthesized by weighting the pixel brightness value of. The matching / combining unit 130 may synthesize a region including the center position of the first matching frame by weighting pixel brightness values of the first matching frame using Equation 5 below.

Where p is the position of the pixel

       a: value between 0 and 1, defined to be smaller as p approaches the control point

       S (p): Pixel brightness value corresponding to p pixels in the first rotating fingerprint frame

       I (p): pixel brightness value corresponding to p pixels in the first matching frame

      U1 (p): pixel brightness value corresponding to p pixels among the frames obtained by combining the first rotating fingerprint frame and the first matching frame

Where p is the position of the pixel

       b: A value between 0 and 1, defined to be smaller as p approaches the control point

       S (p): Pixel brightness value corresponding to p pixels in the first rotating fingerprint frame

      I (p): pixel brightness value corresponding to p pixels in the first matching frame

      U2 (p): pixel brightness value corresponding to p pixels among the frames obtained by combining the first rotating fingerprint frame and the first matching frame

As another example, the matching / combining unit 130 may synthesize the left and the right sides differently based on the second reference line in blocks instead of pixels.

In the above description, a method of synthesizing the left and the right sides with respect to the second reference line using Equations 4 and 5 is different. However, Equations 4 and 5 are just examples. Therefore, instead of Equations 4 and 5, various equations that can give different weights of the region existing on the left side and the weight of the region existing on the right side based on the second reference line may be used.

The rotation fingerprint matching / synthesis apparatus using the reference line may match and synthesize only the rotation fingerprint frames suitable for synthesis among the input rotation fingerprint frames by determining the start or end of the matching and synthesis.

In addition, the rotation fingerprint matching / synthesis apparatus using the baseline informs the user whether the matching or synthesis starts or ends through the output unit, so that the user can easily recognize whether the fingerprint matching or synthesis starts or ends.

In addition, the rotation fingerprint matching / compositing apparatus using the reference line may increase the efficiency of registration and synthesis by extracting the center position value of the rotation fingerprint frame and selecting a matching and synthesis target frame based on the center position value.

Also, the rotation fingerprint matching / compositing device using the reference line sets a control point in an area where the foreground overlaps, moves the control point to a matching point, connects the moved point to set a second reference line, and sets a second reference line. By synthesizing the rotating fingerprint frame using, it is possible to obtain an accurate fingerprint.

2 is a flowchart illustrating a rotation fingerprint matching / synthesis method using a reference line according to an embodiment of the present invention.

1 and 2, the rotation fingerprint matching / synthesis apparatus 100 using the reference line may select a matching and synthesis target frame among the obtained rotation fingerprint frames. For example, the rotation fingerprint matching / compositing apparatus 100 using the reference line may select the first rotation fingerprint frame and the second rotation fingerprint frame among the plurality of rotation fingerprint frames as matching and synthesis target frames. A detailed description thereof will be described with reference to FIG. 5 below. The rotation fingerprint matching / compositing device 100 using the reference line acquires the first rotation fingerprint frame and the second rotation fingerprint frame. The rotation fingerprint matching / compositing device 100 using the reference line extracts a first foreground including the fingerprint of the first rotation fingerprint frame and a second foreground including the fingerprint of the second rotation fingerprint frame (200). The rotation fingerprint matching / synthesis apparatus 100 using the reference line sets a first reference line capable of dividing an area where the first foreground and the second foreground overlap. The rotation fingerprint matching / compositing device 100 using the reference line is included in the second foreground and sets at least one of the points existing on the first reference line as a control point (220). The rotation fingerprint matching / compositing device 100 using the reference line calculates a displacement value up to a point of the first rotation fingerprint frame that matches the control point (230). The rotating fingerprint matching / synthesis apparatus 100 using the reference line generates a first matching frame by matching the second rotating fingerprint frame to the first rotating fingerprint frame based on the displacement value (240). The rotation fingerprint matching / synthesis apparatus 100 using the reference line sets the second reference line by connecting the moved control point after moving the control point by the displacement value (250). The rotation fingerprint matching / synthesis apparatus 100 using the reference line synthesizes the first registration frame and the first rotation fingerprint frame using the second reference line (260). The rotation fingerprint matching / synthesis apparatus 100 using the reference line synthesizes an area including the center position of the first rotation fingerprint frame by weighting the pixel brightness value of the first rotation fingerprint frame based on the second reference line, The region including the center position of the matching frame may be synthesized by weighting the pixel brightness value of the first matching frame. The rotation fingerprint matching / synthesis apparatus 100 using the reference line may repeat the above process to match and synthesize a plurality of rotation fingerprint frames, thereby finally obtaining a fingerprint to be obtained.

Rotational fingerprint matching / synthesis method using a baseline sets a control point in an area where the foreground overlaps, moves the control point to a matching point, connects the moved point to set a second reference line, and uses the second reference line. By synthesizing the rotating fingerprint frame, an accurate fingerprint can be obtained.

3A to 3E are diagrams for describing a method of setting a first reference line in FIG. 2.

Referring to FIG. 3A, the rotation fingerprint matching / compositing apparatus 100 using the reference line uses a line 310a connecting the points 300a and 301a where the outline of the first foreground meets the outline of the second foreground as a first reference line. Can be set.

Referring to FIG. 3B, the rotation fingerprint matching / synthesis apparatus 100 using the baseline points at which the outline of the first foreground meets the outline of the second foreground while morphological erosion of the first foreground and the second foreground. 300b may be extracted, and a line 310b connected to the extracted point 300b may be set as the first reference line.

Referring to FIG. 3C, the rotation fingerprint matching / compositing device 100 using the reference line calculates a center position value 300c corresponding to an area where the first foreground and the second foreground overlap, and passes through the center position value 300c. A straight line 320c perpendicular to the horizontal line 310c may be set as the first reference line.

Referring to FIG. 3D, the rotation fingerprint matching / compositing apparatus 100 using the reference line may have a straight line perpendicular to the line 310d connecting the center position 300d of the first foreground and the center position 301d of the second foreground. 320d) may be set as the first reference line.

Referring to FIG. 3E, the rotation fingerprint matching / synthesis apparatus 100 using the reference line extracts an ellipse 300e using an ellipse fitting algorithm for an area where the first foreground and the second foreground overlap, and ellipses. The straight line 310e passing through the long axis of may be set as the first reference line.

FIG. 4 is a diagram for specifically describing a matching and synthesis method of FIG. 2.

1 and 4, the matching / synthesizing unit 130 includes a first foreground 400 including a fingerprint of a first rotating fingerprint frame and a second foreground 410 including a fingerprint of a second rotating fingerprint frame. Extract The rotation fingerprint matching / compositing device 100 using the reference line matches the first foreground 400 and the second foreground 410. For example, the first foreground 400 and the second foreground 410 may coincide by overlapping the first rotation fingerprint frame and the second rotation fingerprint frame. In another example, the matching / compositing unit 130 matches the feature points such as the endpoints, branch points, and center points of the fingerprints included in the first foreground 400 and the second foreground 410, and thus, the first foreground 400. And the second foreground 410. The matching / combining unit 130 sets a first reference line 420 capable of dividing an area where the first foreground and the second foreground overlap. The matching / combining unit 130 is included in the second foreground 410 and sets at least one of the points existing on the first reference line as the control points 411, 412, 413, and 414. The rotation fingerprint matching / compositing device 100 using the reference line calculates displacement values 431, 432, 433, 434 to the points 401, 402, 403, 404 of the first rotation fingerprint frame that match the control point. . The matching / combining unit 130 generates a first matching frame 440 by matching the second rotating fingerprint frame to the first rotating fingerprint frame based on the displacement value. For example, the matching / combining unit 130 may match the second rotating fingerprint frame to the first rotating fingerprint frame by moving all pixels of the second rotating fingerprint frame based on the calculated displacement value. In this case, the matching / synthesizing unit 130 may determine the moving value of the pixel by interpolating peripheral displacement values. The first registration frame 440 includes a foreground 442 that includes a fingerprint. The matching / combining unit 130 moves the control points 411, 412, 413, and 414 by the displacement value, and then connects the moved control points 401, 402, 403, and 404 to connect the second reference line 441. Set it. The matching / combining unit 130 synthesizes the first matching frame 440 and the first rotating fingerprint frame using the second reference line 441. For example, the registration / synthesis unit 130 includes an area 450 including a central position of the fingerprint included in the first rotating fingerprint frame based on the second reference line, and includes a first foreground 400 of the first rotating fingerprint frame. The pixel brightness values of the first matching frame 440 may be synthesized by weighting the pixel brightness values of the first matching frame 440 by weighting the pixel brightness values of the foreground 442 of the first matching frame. have.

In the rotation fingerprint matching / synthesis method using the baseline, an accurate fingerprint can be obtained by synthesizing two rotation fingerprint frames using the baseline.

FIG. 5 is a diagram for describing a process of selecting a matching and synthesis target frame in FIG. 2.

1 and 5, after starting matching and synthesis, the fingerprint obtaining apparatus 100 may include the first rotating fingerprint frame 500, the second rotating fingerprint frame 510, and the third rotating fingerprint frame 520. The fourth rotating fingerprint frame 530 and the fifth rotating fingerprint frame 540 are obtained. The fingerprint obtaining apparatus 100 extracts the center positions 501, 511, 521, 531, and 541 of the fingerprint included in the rotating fingerprint frames 500, 510, 520, 530, and 540. The fingerprint acquisition apparatus 100 may select a matching and synthesis target frame based on the center positions of the extracted fingerprint.

For example, the fingerprint obtaining apparatus 100 may select the first rotating fingerprint frame 500 among the obtained rotating fingerprint frames 501, 511, 521, 531, and 541 as a first matching and combining target frame. The fingerprint acquiring apparatus 100 performs a second rotation fingerprint frame 520 having a center position value 521 whose distance from the center position value 501 of the first matching and composition target frame 500 is greater than or equal to a threshold value. Select the frame to be matched and synthesized. The fingerprint acquiring apparatus 100 performs a third registration and synthesis on the fourth rotating fingerprint frame 530 having a center position value 531 whose distance from the center position value 521 of the second matching and combining frame is greater than or equal to a threshold value. Can be selected as the target frame. The fingerprint acquisition apparatus 100 executes the above process until it is determined to end matching and synthesis. Finally, the fingerprint obtaining apparatus 100 matches and synthesizes the first rotating fingerprint frame 500, the third rotating fingerprint frame 520, and the fourth rotating fingerprint frame 530.

Although this embodiment has been described based on five rotating fingerprint frames, the present embodiment can be applied regardless of the number of rotating fingerprint frames.

The described embodiments may be configured by selectively combining all or part of the embodiments so that various modifications can be made.

In addition, it should be noted that the embodiments are provided for the purpose of description and not of limitation. In addition, those skilled in the art will understand that various embodiments are possible within the scope of the technical idea of the present invention.

Further, according to an embodiment of the present invention, the above-described method can be implemented as a code that can be read by a processor on a medium on which the program is recorded. Examples of processor-readable media include ROM, RAM, CD-ROM, magnetic tape, floppy disk, optical data storage, and the like, and may be implemented in the form of a carrier wave (for example, transmission over the Internet). Include.

Claims (14)

Setting a first reference line capable of dividing an area where the first foreground including the fingerprint of the first rotating fingerprint frame and the second foreground including the fingerprint of the second rotating fingerprint frame overlap;
Setting at least one of the points included in the second foreground and above the first reference line as a control point;
Calculating a displacement value to a point of the first rotating fingerprint frame that matches the control point;
Generating a first matching frame by matching the second rotating fingerprint frame to the first rotating fingerprint frame based on the displacement value;
Setting the second reference line by connecting the moved control point after moving the control point by the displacement value; And
And synthesizing a first registration frame and a first rotating fingerprint frame using the second reference line.
The method of claim 1,
The synthesizing step,
The region including the center position of the first rotating fingerprint frame is synthesized by weighting the brightness value of the first rotating fingerprint frame based on the second reference line, and the region including the center position of the first matching frame is the first registration. A rotation fingerprint matching / synthesis method using a baseline comprising the step of weighting the brightness value of the frame to synthesize.
The method of claim 1,
The synthesizing step,
The region including the center position of the first rotating fingerprint frame based on the second reference line may be synthesized by adding more weights to the pixel brightness values of the first rotation finger frame among the pixel brightness values of the first rotating fingerprint frame and the first matching frame. The region including the center position of the first registration frame may be combined with a reference line including weighting the pixel brightness value of the first matching frame among the first rotation fingerprint frame and the pixel brightness values of the first matching frame. Rotational fingerprint matching / synthesis method.
The method of claim 1,
And selecting a matching and synthesis target frame based on the center position values of the fingerprints included in the obtained rotation fingerprint frames.
The method of claim 4, wherein
The step of selecting the matching and composition target frame,
Extracting a central position value of the fingerprint included in the obtained rotation fingerprint frames after starting matching and synthesis;
Selecting a first matching and composition target frame among the obtained rotating fingerprint frames;
Selecting a rotating fingerprint frame having a center position value whose distance from the center position value of the first registration and synthesis target frame is greater than or equal to a threshold value as a second registration / synthesis target frame; And
Rotating fingerprint matching / synthesis using a reference line comprising selecting a rotating fingerprint frame having a center position value whose distance from the center position value of the second registration / synthesis target frame is greater than or equal to a threshold value as a third matching / synthesis target frame. Way.
The method of claim 1,
The setting of the first reference line may include:
And connecting the point where the outline of the first foreground meets the outline of the second foreground to set a first reference line.
The method of claim 1,
The setting of the first reference line may include:
Extracting a point at which the outline of the first eggplant meets the outline of the second foreground while morphological erosion of the first foreground and the second foreground; And
Rotating fingerprint matching / synthesis method using a reference line comprising the step of setting the first reference line by connecting the extracted points.
The method of claim 1,
The setting of the first reference line may include:
Calculating a center position corresponding to the overlapping area; And
And setting a straight line perpendicular to the horizontal axis passing through the center position as a first reference line.
The method of claim 1,
The setting of the first reference line may include:
And a straight line perpendicular to a line connecting the center position of the first foreground and the center position of the second foreground to the first reference line.
The method of claim 1,
The setting of the first reference line may include:
Extracting an ellipse for the overlapping region using an ellipse fitting algorithm; And
And setting a straight line passing through the long axis of the ellipse as a first reference line.
A rotating fingerprint frame obtaining unit obtaining a first rotating fingerprint frame and a second rotating fingerprint frame; And
Set a first reference line to divide an area where the first foreground including the fingerprint of the first rotating fingerprint frame and the second foreground including the fingerprint of the second rotating fingerprint frame overlap, and are included in the second foreground; Set at least one of the points above the first reference line as a control point, calculate a displacement value to the point of the first rotating fingerprint frame that matches the control point, and based on the displacement value Generating a first registration frame by matching a second rotating fingerprint frame to the first rotating fingerprint frame, moving the control point by the displacement value, connecting the moved control point to set a second reference line, and Rotational fingerprint registration / St. devices.
The method of claim 11,
The matching / synthesis unit,
The area including the center position of the first rotation fingerprint frame is synthesized by weighting the pixel brightness value of the first rotation fingerprint frame based on the second reference line, and the area including the center position of the first registration frame is the first position. A rotation fingerprint matching / compositing device using a baseline that synthesizes weights of pixel brightness values of a matching frame.
The method of claim 11,
And a selection unit for selecting a matching and combining target frame based on a center position value of the fingerprint included in the rotating fingerprint frames obtained after starting the matching and combining.
The method of claim 13,
The selection unit,
Extracts the central position value of the fingerprint included in the obtained rotating fingerprint frames after starting the matching and combining, selects a first matching and combining target frame among the obtained rotating fingerprint frames, and performs the first matching and combining A rotation fingerprint frame having a center position value whose distance from the center position value of the target frame is greater than or equal to the threshold is selected as the second matching / synthesis target frame, and the distance from the center position value of the second matching / synthesis target frame is critical. A rotation fingerprint matching / synthesis device using a reference line for selecting a rotation fingerprint frame having a center position value equal to or greater than a value as a third matching / synthesis target frame.

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