JP2010073115A - Fingerprint-inputting device, method and program - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a fingerprint-inputting device, method and program which can deal with high-speed sweeping of a finger when inputting the fingerprint. <P>SOLUTION: The method includes: searching ridge lines of a crest pattern of a fingerprint in a rectangular 1-frame image from a left end of the lower side toward a right direction, from a right end of the lower side toward a left direction, from a left end of the upper side toward the right, and from a right end of the upper side toward the left, respectively; establishing vectors S1 and S2 by setting the points found by these searches to respective starting points and end points; establishing points b'1 and b'2, which have the same X coordinates as respective end points of vectors S1 and S2, on the base of a new 1-frame image contiguous to the preceding 1-frame image; establishing extended lines of vectors S1 and S2 by setting these points to respective starting points; establishing an area enclosed by the extended lines of vectors S1 and S2, the upper side of the new 1-frame image and the lower side of the new 1-frame image; and executing processing of extracting the fingerprint by limiting to this area. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an apparatus for inputting a fingerprint image by sweeping a finger on a line fingerprint sensor composed of a plurality of lines, a method thereof, and a program thereof.

  In recent years, apart from user authentication using passwords, biometric authentication that performs user authentication based on individual physical characteristics has been used in various fields such as IT.

  Among these, a technique for identifying an individual using a fingerprint is widely used because it is simpler than other biometric authentication techniques for reading the retina or iris.

Therefore, Patent Documents 1 to 4 disclose an invention in which a fingerprint image is input by sweeping (sweeping) a finger on a line fingerprint sensor.
JP 2003-067749 A JP 2006-072758 A JP 2006-209364 A Japanese Patent No. 2725599

  However, in the inventions disclosed in Patent Documents 1 to 4, the finger area is determined from all the pixels of the acquired one-frame image. This method has a problem that it takes time to process because the finger region must be extracted from the entire one frame image.

  The fact that the fingerprint input processing is slow cannot cope with a high-speed sweep, and the usability of fingerprint input is impaired.

  The present invention has been made in view of the above, and an object of the present invention is to provide a fingerprint input device, a method thereof, and a program thereof that can cope with a high-speed sweep.

  In order to solve the above-described problems, a fingerprint input device according to the present invention reads a fingerprint of a finger swept on a line fingerprint sensor that reads a strip-shaped image as a plurality of continuous strip-shaped images, and the plurality of strip-shaped images. In a fingerprint input device that acquires image data of a fingerprint by combining images, a central processing unit having a RAM (Random Access Memory), a ROM (Read Only Memory) and a CPU (Central Processing Unit), and a RAM or hard disk The central processing unit, with respect to one frame image that is one of the strip-shaped images, from the left end of the lower side of the one frame image to the right direction, and from the right end of the lower side to the left direction, Search for ridges that are raised with the fingerprint pattern from the left edge of the upper side of the one-frame image to the right and from the right edge of the upper side to the left. Starting from the position of the lower left ridge that is the first point on the ridge found in the right search from the left end of the lower side, the upper left that is the point on the ridge that was first found in the right search from the left end of the upper side The left edge ridge direction vector with the edge ridge position as the end point, and the right lower edge ridge position that is the first point on the ridge found in the leftward search from the right edge of the lower edge, and the left edge from the right edge of the upper edge. A right edge ridge direction vector whose end point is an upper right edge ridge position, which is a point on the ridge first discovered by the direction search, is set on the bottom of a new one frame image continuous to the one frame image. An extension line of the left edge ridge direction vector is set starting from a point having the same X coordinate as the certain left upper edge ridge position, and the upper right edge ridge position and X coordinate on the bottom of the new one-frame image are set. Starting from the same point, the right edge ridge direction An extension line of Kutor is set, and an extension line of the left edge ridge direction vector, an extension line of the right edge ridge direction vector, an upper side of the new one frame image, and a lower side of the new one frame image A region to be surrounded is set, and fingerprint extraction processing is performed only on the region.

  In order to solve the above-mentioned problems, a fingerprint input method according to the present invention reads a fingerprint of a finger swept on a line fingerprint sensor that reads a strip-shaped image, and reads the plurality of strip-shaped images as a plurality of continuous strip-shaped images. In a fingerprint input method for acquiring image data of a fingerprint by combining images, a processing procedure in a central processing unit having a RAM (Random Access Memory), a ROM (Read Only Memory), and a CPU (Central Processing Unit) A processing procedure in a storage device having a RAM or a hard disk, and the processing procedure in the central processing unit is based on a lower side of the one-frame image with respect to one frame image that is one of the strip-shaped images. The left and right edges of the one-frame image are printed in the right direction from the left edge to the right, the left edge of the upper side of the one-frame image is moved to the right, and the right edge of the upper side is moved to the left. Starting from the left lower edge ridge position, which is the point on the ridge first found in the search from the left edge of the lower side to the right, starting from the left lower edge ridge position, starting from the left edge of the upper side The left edge ridge direction vector whose end point is the upper left ridge position, which is the first point on the ridge found in the right direction search, and the point on the ridge first found in the left direction search from the right end of the lower side. A procedure for setting a right edge ridge direction vector starting from a certain right lower edge ridge position and having an upper right edge ridge position as an end point, which is a point on the ridge first found in the left direction search from the right edge of the upper side. A procedure for setting an extension line of the left edge ridge direction vector starting from a point having the same X coordinate as the left upper edge ridge position on the bottom of a new one frame image continuous to the one frame image; On the bottom of the new one-frame image A procedure for setting an extension line of the right end ridge direction vector starting from a point having the same X coordinate as the upper right end ridge position, an extension line of the left end ridge direction vector, and an extension of the right end ridge direction vector A procedure for setting an area surrounded by a line, an upper side of the new one-frame image, and a lower side of the new one-frame image, and a procedure for performing a fingerprint extraction process limited to the area. Features.

  In order to solve the above-described problems, a fingerprint input program according to the present invention reads a fingerprint of a finger swept on a line fingerprint sensor that reads a strip-shaped image as a plurality of continuous strip-shaped images, and the plurality of strip-shaped images In a fingerprint input program for acquiring image data of a fingerprint by synthesizing an image, processing in a central processing unit having a RAM (Random Access Memory), a ROM (Read Only Memory) and a CPU (Central Processing Unit), and a RAM Or processing in a storage device having a hard disk, and the processing in the central processing unit is performed in the right direction from the left end of the lower side of the one frame image with respect to one frame image which is one of the strip-like images. The fingerprint pattern swells from the right edge of the lower edge to the left, from the left edge of the upper edge of the one-frame image to the right, and from the right edge of the upper edge to the left. Each of the ridges that are located on the left side of the lower side, and a left ridge position that is a point on the ridge that is first found in the search from the left side of the lower side to the right side. Left end ridge direction vector whose end point is the upper left ridge position, which is the first point on the ridge found in the search, and lower right end, which is the first point on the ridge found in the left direction search from the right end of the lower side A process for setting a right edge ridge direction vector having a ridge position as a start point, and an upper right edge ridge position that is a point on the ridge first found in a leftward search from the right edge of the upper side, and an end point; and A process of setting an extension line of the left edge ridge direction vector starting from a point having the same X coordinate as the left upper edge ridge position on the bottom of a new one frame image continuous to the one frame image; The right above the bottom of one frame image A process of setting an extension line of the right edge ridge direction vector starting from a point having the same X coordinate as the upper edge ridge position; an extension line of the left edge ridge direction vector; an extension line of the right edge ridge direction vector; , Causing a computer to execute a process of setting an area surrounded by an upper side of the new one-frame image and a lower side of the new one-frame image, and a process of performing a fingerprint extraction process limited to the area It is characterized by.

  According to the present invention, on the new one frame image, the extension line of the left edge ridge direction vector and the right edge ridge direction vector respectively set from the points on the ridge on the immediately preceding one frame image, and the new one frame By setting a region surrounded by the upper side of the image and the lower side of the new one-frame image and performing fingerprint extraction processing only on this region, only the region where it is assumed that a finger is present from the entire region of the frame image Compared with the case where the entire frame image region is processed, the amount of calculation for one frame can be reduced, and a fingerprint input device, method and program thereof that can cope with a higher-speed sweep Can be provided.

Next, embodiments of the present invention will be described in detail with reference to the drawings.
[First Embodiment]
FIG. 1 is a configuration diagram of a fingerprint input device according to a first embodiment of the present invention.

  In FIG. 1, the fingerprint input device according to the present embodiment reads a fingerprint of a finger swept over the line fingerprint sensor as a plurality of continuous strip images, and synthesizes the plurality of strip images. A fingerprint input device for acquiring image data of the fingerprint by a line fingerprint sensor 11 for reading a strip-shaped image, a RAM (Random Access Memory), a ROM (Read Only Memory), and a CPU (Central Processing Unit). A central processing unit 12 configured; a current one-frame storage device 13 that stores a current one-frame image; and a lower-left ridge position storage device 14 that stores a lower-left ridge position of the immediately preceding one-frame image; A lower right ridge position storage device 15 for storing the ridge position at the lower right corner of the immediately preceding frame image, and a left upper edge ridge position storage device 16 for storing the ridge position at the upper left corner of the immediately previous frame image. An upper right edge ridge position storage device 17 for storing the upper right edge ridge position of the immediately preceding frame image, a left edge ridge direction storage device 18 for storing the left edge ridge direction of the immediately preceding frame image, and a right edge ridge of the immediately preceding frame image. And a right-end ridge direction storage device 19 for storing the line direction.

  Current one-frame storage device 13, left lower ridge position storage device 14, right lower ridge position storage device 15, left upper ridge position storage device 16, upper right ridge position storage device 17, left end ridge direction storage device 18 The right-end ridge direction storage device 19 is a storage device composed of a RAM (Random Access Memory) or a hard disk, which is an information storage medium, and is connected to the central processing unit 12 such as LAN, RS232C serial communication or bus signal line. Connected with.

  Currently, the capacity of the information storage medium of the one-frame storage device 13 requires a capacity capable of storing an image acquired from the line fingerprint sensor 11.

  The capacity of the information storage medium of the lower left ridge position storage device 14, the lower right ridge position storage device 15, the upper left ridge position storage device 16 and the upper right ridge position storage device 17 is calculated by the central processing unit 12. In addition, a capacity capable of storing an arbitrary position on one frame image is required.

  The capacity of the information storage medium of the left end ridge direction storage device 18 and the right end ridge direction storage device 19 requires a capacity capable of storing the left and right end ridge directions calculated by the central processing unit 12.

  In order to input a fingerprint to the fingerprint input device according to the present embodiment, the input finger 22 is placed sideways so as to intersect the line fingerprint sensor 11 vertically as shown in FIG. As shown, the sweep is performed in the direction of the arrow (sweep direction 23). Thereby, a horizontally long strip-like image of the fingerprint image as shown in FIG. 3 is continuously acquired from the line fingerprint sensor 11.

  Next, the operation of the fingerprint input device according to the present embodiment will be described with reference to the block diagram of FIG. 1 and the diagrams of FIGS. 4 to 11.

  When the fingerprint input is started, the central processing unit 12 in FIG. 1 acquires one frame image (frame image A) of a strip-shaped image as shown in FIG. 3 from the line fingerprint sensor 11, and the image is currently displayed in one frame. Store in the storage device 13. The curve depicted in FIG. 3 is a “ridge” that is a raised portion with a fingerprint pattern.

  Next, as shown in FIG. 4, the central processing unit 12 changes the pixel value of the first ridge from the left end of the lower side of the frame image A in the current one-frame storage device 13 in the direction A1 (right direction). Search from etc. And let the point of the found ridge be the lower left ridge position a1.

  The coordinates (Xa1, Ya1) of this point a1 are stored in the left bottom ridge position storage device 14. At this time, the coordinates are obtained from coordinate values in which the left end of the lower side of one frame image is the origin O, the number of pixels in the right direction is the X coordinate, and the number of pixels in the upper direction is the Y coordinate.

Similarly, as shown in FIG. 5, the first ridge is searched in the direction A2 (left direction) from the right end of the lower side in one frame image. Then, the found ridge point is set as the lower right ridge position a2, and the coordinates (Xa2, Ya2) are stored in the lower right ridge position storage device 15.
Further, as shown in FIG. 6, which schematically depicts one frame image in the current one frame storage device 13, the central processing unit 12 starts from the left end of the upper side of the one frame image in the direction B1 (right direction). Exploring the ridges. Then, the point of the found ridge is set as the upper left ridge position b1, and the coordinates (Xb1, Yb1) are stored in the upper left ridge position storage device 16.

  Similarly, as shown in FIG. 7, the first ridge is searched in the direction B2 (left direction) from the right end of the upper side in one frame image. The found ridge point is set as the upper right ridge position b2, and the coordinates (Xb2, Yb2) are stored in the upper right ridge position storage device 17.

  FIG. 8 shows the calculated points a1, a2, b1, and b2 on one frame image at the same time.

  Next, the central processing unit 12 calculates the component of the vector S1, which is the left-end ridge direction vector having the point a1 as the start point and the point b1 as the end point, by the following equation, and stores it in the left-end ridge direction storage device 18.

S1 = (Xb1-Xa1, Yb1-Ya1)
Similarly, the component of the vector S2, which is the right edge ridge direction vector starting from the point a2 and ending at the point b2, is also calculated by the following equation and stored in the right edge ridge direction storage device 19.

S2 = (Xb2-Xa2, Yb2-Ya2)
FIG. 9 shows the vector S1 and the vector S2 as thick arrows on one frame image.

  Next, the central processing unit 12 acquires the next new one-frame image (frame image B) from the line fingerprint sensor 11 and stores the image in the current one-frame storage device 13.

  From the points b1 and b2 calculated so far on the bottom of a new one-frame image (frame image B) continuous to the one-frame image, as represented by the following equation, the upper left ridge position b1 and X B′1 that is the same coordinate and b′2 that is the same as the right upper edge ridge position b2 and the X coordinate are set, and a vector S1 that is a left edge ridge direction vector starting from the point b′1. And the vector S2 which is a right edge ridge direction vector is set as shown in FIG. 10 starting from the point b′2. In this case, the origin O is the left end of the lower side of the new one-frame image.

b′1 = (Xb1, 0)
b′2 = (Xb2, 0)
Point b′1, point b′2, a point where an extension line of vector S1 starting from point b′1 intersects with the upper side, and a point where an extension line of vector S2 starting from point b′2 intersects the upper side 11 is set, and the fingerprint extraction process is performed on the limited area.

  This area is also an area surrounded by the extension line of the left end ridge direction vector, the extension line of the right end ridge direction vector, the upper side of the new one-frame image, and the lower side of the new one-frame image.

  Further, the central processing unit sets an area as described above for a plurality of continuous strip-shaped images, that is, each one frame image that exists continuously, and performs the fingerprint extraction process only on this area.

As described so far, the next one frame image obtained from the upper left ridge position, the upper right edge ridge position, the left edge ridge direction vector and the right edge ridge direction vector obtained from the previous one frame image By repeatedly estimating the area where the finger is considered to be present, the area where the fingerprint extraction process should be performed can be limited, and the processing time can be shortened.
[Second Embodiment]
A second embodiment according to the present invention will be described. In the present invention, the ridge direction vector at the left and right ends is calculated as a straight line. However, the ridge direction vector may be configured by a curve in consideration of the curvature of the ridge.

  Further, in the present invention, the region surrounded by the upper left ridge position, the upper right ridge position, the left ridge direction vector, and the right ridge direction vector is set as an area in which the finger of the next frame image is estimated to exist. However, considering that the finger moves in the horizontal direction, the finger region may be estimated by extending the horizontal width of the region by at least one pixel.

  The present invention can be used for a fingerprint input device used in biometric authentication.

It is a block diagram of the fingerprint input device which concerns on the 1st Embodiment in this invention. It is a figure which shows the mode of the fingerprint reading in the fingerprint input device which concerns on 1st Embodiment in this invention. It is a figure which shows the frame image A which the fingerprint input device concerning the 1st Embodiment in this invention read. It is a figure regarding the process of the frame image A which the fingerprint input device concerning the 1st Embodiment in this invention read. It is a figure regarding the process of the frame image A which the fingerprint input device concerning the 1st Embodiment in this invention read. It is a figure regarding the process of the frame image A which the fingerprint input device concerning the 1st Embodiment in this invention read. It is a figure regarding the process of the frame image A which the fingerprint input device concerning the 1st Embodiment in this invention read. It is a figure regarding the process of the frame image A which the fingerprint input device concerning the 1st Embodiment in this invention read. It is a figure regarding the process of the frame image A which the fingerprint input device concerning the 1st Embodiment in this invention read. It is a figure regarding the process of the frame image B which the fingerprint input device concerning the 1st Embodiment in this invention read. It is a figure regarding the process of the frame image B which the fingerprint input device concerning the 1st Embodiment in this invention read.

Explanation of symbols

11 Line fingerprint sensor 12 Central processing unit 13 Current one frame storage device 14 Left lower end ridge position storage device 15 Right lower end ridge position storage device 16 Left upper end ridge position storage device 17 Upper right end ridge position storage device 18 Left end ridge Direction storage device 19 Right edge ridge direction storage device 22 Input finger 23 Sweep direction

Claims (18)

A fingerprint input device that reads a fingerprint of a finger scanned on a line fingerprint sensor as a plurality of continuous strip-shaped images and synthesizes the plurality of strip-shaped images to acquire the image data of the fingerprint In
A central processing unit having a RAM (Random Access Memory), a ROM (Read Only Memory) and a CPU (Central Processing Unit), and a storage device having a RAM or a hard disk;
The central processing unit is
For one frame image which is one of the strip-shaped images, from the left end of the lower side of the one frame image to the right direction, from the right end of the lower side to the left direction, from the left end of the upper side of the one frame image to the right direction, From the right edge of the upper side to the left, search for each ridge that is raised with the fingerprint pattern,
Starting from the position of the lower left ridge that is the first point on the ridge found in the right search from the left end of the lower side, the upper left that is the point on the ridge that was first found in the right search from the left end of the upper side The left edge ridge direction vector with the edge ridge position as the end point, and the right lower edge ridge position that is the first point on the ridge found in the leftward search from the right edge of the lower edge, and the left edge from the right edge of the upper edge. Set the right edge ridge direction vector with the upper right edge ridge position as the end point, which is the first point on the ridge found in the direction search, and
An extension line of the left edge ridge direction vector is set starting from a point having the same X coordinate as the left upper edge ridge position on the bottom of a new one frame image continuous to the one frame image;
Set an extension line of the right edge ridge direction vector starting from a point having the same X coordinate as the position of the upper right edge ridge on the bottom of the new one-frame image,
Setting an area surrounded by an extension line of the left edge ridge direction vector, an extension line of the right edge ridge direction vector, an upper side of the new one-frame image, and a lower side of the new one-frame image;
A fingerprint input device that performs fingerprint extraction processing only in the region.   The central processing unit, for each of the continuous strip-like images, an extension line of the left end ridge direction vector, an extension line of the right end ridge direction vector, an upper side of the strip-like image, and the strip The fingerprint input device according to claim 1, wherein an area surrounded by a lower side of the image is set, and fingerprint extraction processing is performed only on the area. The central processing unit is
The left end of the lower side of the one-frame image that is one of the first strip-shaped images is defined as an origin O,
The left lower ridge position is point a1, the coordinates are (Xa1, Ya1),
The right bottom ridge position is point a2, the coordinates are (Xa2, Ya2),
The position of the upper left ridge is the point b1, the coordinates thereof are (Xb1, Yb1),
The upper right edge ridge position is point b2, and its coordinates are (Xb2, Yb2).
The component of the left edge ridge direction vector is (Xb1-Xa1, Yb1-Ya1),
The component of the right edge ridge direction vector is (Xb2-Xa2, Yb2-Ya2),
When the point of the left upper edge ridge position on the bottom of the new one-frame image and the X coordinate is the same as the point b′1, and the left end of the lower side of the new one-frame image is the origin O, the coordinates are (Xb1,0)
When a point where the X coordinate is the same as the upper right edge ridge position on the bottom of the new one-frame image is a point b′2, and the left end of the lower side of the new one-frame image is an origin O, the coordinates are The fingerprint input device according to claim 1 or 2, wherein (Xb2, 0) is used. The storage device
A current one-frame storage device for storing the new one-frame image;
A left bottom ridge position storage device for storing the left bottom ridge position;
A right bottom ridge position storage device for storing the right bottom ridge position;
A left upper ridge position storage device for storing the upper left ridge position;
An upper right edge ridge position storage device for storing the upper right edge ridge position;
A left end ridge direction storage device for storing a component of the left end ridge direction vector;
A right edge ridge direction storage device for storing a component of the right edge ridge direction vector;
The fingerprint input device according to claim 1, further comprising:   5. The central processing unit according to claim 1, wherein the central processing unit sets the region by a curve considering a curvature of a fingerprint ridge instead of the left end ridge direction vector and the right end ridge direction vector. The fingerprint input device according to any one of the above.   The fingerprint input device according to claim 1, wherein the central processing unit expands the width of the region by at least one pixel. A fingerprint input method for reading a fingerprint of a finger swept on a line fingerprint sensor that reads a strip-shaped image as a plurality of continuous strip-shaped images and combining the plurality of strip-shaped images to obtain image data of the fingerprint In
A processing procedure in a central processing unit having a RAM (Random Access Memory), a ROM (Read Only Memory) and a CPU (Central Processing Unit), and a processing procedure in a storage device having a RAM or a hard disk;
The processing procedure in the central processing unit is as follows:
For one frame image which is one of the strip-shaped images, from the left end of the lower side of the one frame image to the right direction, from the right end of the lower side to the left direction, from the left end of the upper side of the one frame image to the right direction, A procedure for searching for a ridge that is a raised portion of the fingerprint pattern from the right edge of the upper side to the left,
Starting from the position of the lower left ridge that is the first point on the ridge found in the right search from the left end of the lower side, the upper left that is the point on the ridge that was first found in the right search from the left end of the upper side The left edge ridge direction vector with the edge ridge position as the end point, and the right lower edge ridge position that is the first point on the ridge found in the leftward search from the right edge of the lower edge, and the left edge from the right edge of the upper edge. A procedure for setting a right edge ridge direction vector whose end point is an upper right edge ridge position that is a point on the ridge that is first found in the direction search;
A procedure for setting an extension line of the left edge ridge direction vector starting from a point having the same X coordinate as the left upper edge ridge position on the bottom of a new one frame image continuous to the one frame image;
A procedure for setting an extension line of the right edge ridge direction vector starting from a point having the same X coordinate as the position of the upper right edge ridge on the bottom of the new one-frame image;
A procedure for setting an area surrounded by an extension line of the left end ridge direction vector, an extension line of the right end ridge direction vector, an upper side of the new one-frame image, and a lower side of the new one-frame image; ,
A procedure for performing fingerprint extraction processing only in the region;
A fingerprint input method comprising:   The processing procedure in the central processing unit includes, for each of the plurality of continuous strip images, an extension line of the left end ridge direction vector, an extension line of the right end ridge direction vector, and the strip image. 8. The fingerprint input method according to claim 7, wherein a region surrounded by an upper side and a lower side of the strip-shaped image is set, and fingerprint extraction processing is performed only on the region. The processing procedure in the central processing unit is as follows:
The left end of the lower side of the one-frame image that is one of the first strip-shaped images is defined as an origin O,
The left lower ridge position is point a1, the coordinates are (Xa1, Ya1),
The right bottom ridge position is point a2, the coordinates are (Xa2, Ya2),
The position of the upper left ridge is the point b1, the coordinates thereof are (Xb1, Yb1),
The upper right edge ridge position is point b2, and its coordinates are (Xb2, Yb2).
The component of the left edge ridge direction vector is (Xb1-Xa1, Yb1-Ya1),
The component of the right edge ridge direction vector is (Xb2-Xa2, Yb2-Ya2),
When the point of the left upper edge ridge position on the bottom of the new one-frame image and the X coordinate is the same as the point b′1, and the left end of the lower side of the new one-frame image is the origin O, the coordinates are (Xb1,0)
When a point where the X coordinate is the same as the upper right edge ridge position on the bottom of the new one-frame image is a point b′2, and the left end of the lower side of the new one-frame image is an origin O, the coordinates are 9. The fingerprint input method according to claim 7, wherein (Xb2, 0) is set. The processing procedure in the storage device is as follows:
Storing the left bottom ridge position;
Storing the right bottom ridge position;
Storing the left upper ridge position;
Storing the upper right edge ridge position;
Storing a component of the left edge ridge direction vector;
Storing a component of the right edge ridge direction vector;
Storing the new one-frame image;
The fingerprint input method according to claim 7, further comprising:   The processing procedure in the central processing unit is characterized in that, instead of the left end ridge direction vector and the right end ridge direction vector, the region is set by a curve in consideration of the curvature of a fingerprint ridge. Item 11. The fingerprint input method according to any one of Items 7 to 10.   11. The fingerprint input method according to claim 7, wherein in the processing procedure in the central processing unit, the horizontal width of the region is expanded by at least one pixel. A fingerprint input program that reads a fingerprint of a finger scanned on a line fingerprint sensor as a plurality of continuous strip-shaped images and synthesizes the plurality of strip-shaped images to obtain image data of the fingerprint In
Processing in a central processing unit having RAM (Random Access Memory), ROM (Read Only Memory) and CPU (Central Processing Unit), and processing in a storage device having RAM or a hard disk,
The processing in the central processing unit is as follows:
For one frame image which is one of the strip-shaped images, from the left end of the lower side of the one frame image to the right direction, from the right end of the lower side to the left direction, from the left end of the upper side of the one frame image to the right direction, A process of searching for ridges that are raised from the right edge of the upper side to the left,
Starting from the position of the lower left ridge that is the first point on the ridge found in the right search from the left end of the lower side, the upper left that is the point on the ridge that was first found in the right search from the left end of the upper side The left edge ridge direction vector with the edge ridge position as the end point, and the right lower edge ridge position that is the first point on the ridge found in the leftward search from the right edge of the lower edge, and the left edge from the right edge of the upper edge. A process for setting a right edge ridge direction vector whose end point is an upper right edge ridge position, which is a point on the ridge that is first found in the direction search;
A process of setting an extension line of the left edge ridge direction vector starting from a point having the same X coordinate as the left upper edge ridge position on the bottom of a new one frame image continuous to the one frame image;
A process of setting an extension line of the right edge ridge direction vector starting from a point having the same X coordinate as the position of the upper right edge ridge on the bottom of the new one-frame image;
Processing for setting an area surrounded by an extension line of the left edge ridge direction vector, an extension line of the right edge ridge direction vector, an upper side of the new one-frame image, and a lower side of the new one-frame image; ,
Processing to perform fingerprint extraction processing limited to the area;
A fingerprint input program that causes a computer to execute.   The processing in the central processing unit includes, for each of the continuous strip-like images, an extension line of the left end ridge direction vector, an extension line of the right end ridge direction vector, and an upper side of the strip-like image. 14. The fingerprint input program according to claim 13, wherein a region surrounded by the lower side of the strip-shaped image is set, and fingerprint extraction processing is performed only on the region. The processing in the central processing unit is as follows:
The left end of the lower side of the one-frame image that is one of the first strip-shaped images is defined as an origin O,
The left lower ridge position is point a1, the coordinates are (Xa1, Ya1),
The right bottom ridge position is point a2, the coordinates are (Xa2, Ya2),
The position of the upper left ridge is the point b1, the coordinates thereof are (Xb1, Yb1),
The upper right edge ridge position is point b2, and its coordinates are (Xb2, Yb2).
The component of the left edge ridge direction vector is (Xb1-Xa1, Yb1-Ya1),
The component of the right edge ridge direction vector is (Xb2-Xa2, Yb2-Ya2),
When the point of the left upper edge ridge position on the bottom of the new one-frame image and the X coordinate is the same as the point b′1, and the left end of the lower side of the new one-frame image is the origin O, the coordinates are (Xb1,0)
When a point where the X coordinate is the same as the upper right edge ridge position on the bottom of the new one-frame image is a point b′2, and the left end of the lower side of the new one-frame image is an origin O, the coordinates are 15. The fingerprint input program according to claim 13 or 14, wherein (Xb2, 0) is set. The processing in the storage device is as follows:
A process of storing the left bottom ridge position;
Processing for storing the right bottom ridge position;
Processing for storing the left upper ridge position;
A process of storing the upper right edge ridge position;
Processing for storing a component of the left edge ridge direction vector;
Processing for storing the right edge ridge direction vector component;
Storing the new one-frame image;
The fingerprint input program according to claim 13, wherein the program is executed by a computer.   14. The processing in the central processing unit is characterized in that, instead of the left edge ridge direction vector and the right edge ridge direction vector, the region is set by a curve considering the curvature of a fingerprint ridge. The fingerprint input program according to any one of 1 to 16.   The fingerprint input program according to any one of claims 13 to 16, wherein the processing in the central processing unit expands the width of the region by at least one pixel.

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