U.S. patent application number 09/887652 was filed with the patent office on 2001-11-01 for fingerprint registering method and fingerprint checking device.
This patent application is currently assigned to Fujitsu Denso Ltd. Japanese Corporation. Invention is credited to Ogawa, Atsushi, Ooka, Yasuo, Taniguchi, Kiyohide, Uchida, Naoya, Yamaguchi, Masahiko.
Application Number | 20010036301 09/887652 |
Document ID | / |
Family ID | 27547848 |
Filed Date | 2001-11-01 |
United States Patent
Application |
20010036301 |
Kind Code |
A1 |
Yamaguchi, Masahiko ; et
al. |
November 1, 2001 |
Fingerprint registering method and fingerprint checking device
Abstract
The present invention can achieve the reliability and simplicity
in registering a fingerprint by indicating the quality of a
fingerprint image by the number of pseudo minutiae, improve the
security of an entrance/exit control system to register a
fingerprint, detect the direction of ridge lines of a fingerprint
accurately as much as possible, improve the security in checking a
fingerprint remarkably, collect renewed registered fingerprint data
by a host device and hold the registered fingerprint data of each
gate as the latest fingerprint data, improve the operability by
enabling to use identification numbers having the less number of
digits, and register a fingerprint having a high match rate by
automatically applying spatial filtering in re-registering only. A
fingerprint registering method according to the present invention
detects normal minutiae and pseudo minutiae in a fingerprint
pictured by a fingerprint image pickup unit, counts pseudo minutiae
in registering windows with normal minutiae at almost the center,
determines the average number of pseudo minutiae in registering
windows from a total of pseudo minutiae in all registering windows,
and registers a fingerprint when the average number of pseudo
minutiae is equal to or below a threshold.
Inventors: |
Yamaguchi, Masahiko;
(Kawasaki-shi, JP) ; Ooka, Yasuo; (Kawasaki-shi,
JP) ; Uchida, Naoya; (Kawasaki-shi, JP) ;
Ogawa, Atsushi; (Kawasaki-shi, JP) ; Taniguchi,
Kiyohide; (Kawasaki-shi, JP) |
Correspondence
Address: |
BLACKWELL SANDERS PEPER MARTIN LLP
720 OLIVE STREET, SUITE 2400
ST. LOUIS
MO
63101
US
|
Assignee: |
Fujitsu Denso Ltd. Japanese
Corporation
|
Family ID: |
27547848 |
Appl. No.: |
09/887652 |
Filed: |
June 22, 2001 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
09887652 |
Jun 22, 2001 |
|
|
|
08813627 |
Mar 7, 1997 |
|
|
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Current U.S.
Class: |
382/125 |
Current CPC
Class: |
G06V 40/1347 20220101;
H01L 27/14868 20130101; G06T 7/33 20170101; H01L 27/14825
20130101 |
Class at
Publication: |
382/125 |
International
Class: |
G06K 009/00 |
Foreign Application Data
Date |
Code |
Application Number |
Jan 16, 1996 |
JP |
8-004489 |
Jan 16, 1996 |
JP |
8-004490 |
Mar 28, 1996 |
JP |
8-073505 |
Oct 5, 1995 |
JP |
7-258504 |
Nov 21, 1995 |
JP |
7-302437 |
Dec 18, 1995 |
JP |
7-328484 |
Claims
What is claimed is:
1. A fingerprint registering method comprising: detecting normal
minutiae and pseudo minutiae of a fingerprint pictured by a
fingerprint image pickup unit, counting the number of said pseudo
minutiae in registering windows with said normal minutiae at almost
the center, determining the average number of pseudo minutiae in
the registering windows from a total of pseudo minutiae in all
registering windows, and registering said fingerprint when said
average number of pseudo minutiae is equal to or below a
threshold.
2. The fingerprint registering method according to claim 1, wherein
when said average number of pseudo minutiae in the registering
windows exceeds the threshold, registering of another fingerprint
is instructed, and fingers are sequentially registered until a
fingerprint with the average number of pseudo minutiae in the
registering windows equal to or below the threshold is
obtained.
3. The fingerprint registering method according to claim 1, wherein
when said average number of pseudo minutiae in the registering
windows exceeds the threshold, registering of another fingerprint
is instructed, a finger having the minimum average number of pseudo
minutiae in the registering windows is selected as the best finger,
and the fingerprint of said best finger is registered.
4. A fingerprint checking device comprising: a fingerprint image
pickup unit, an image processor unit for thinning processing a
pictured image by said fingerprint image pickup unit, a minutia
detecting unit for detecting normal minutiae and pseudo minutiae
from the thinning-processed image from said image processor unit,
an average pseudo minutia calculating unit for calculating the
average number of pseudo minutiae in all registering windows by
counting said pseudo minutiae in the registering windows with said
normal minutiae at almost the center, a registering unit for
registering a fingerprint, a judging unit for comparing said
average number of pseudo minutiae from said average pseudo minutia
calculating unit with a threshold to register the fingerprint in
said registering unit when said average number of pseudo minutiae
is equal to or below said threshold, a display unit for showing
said average number of pseudo minutiae from said average minutiae
calculating unit or information which corresponds to said average
number of pseudo minutiae, and a checking unit for checking the
fingerprint registered in said registering unit with the
fingerprint pictured by said fingerprint image pickup unit.
5. The fingerprint checking device according to claim 4, wherein
said judging unit displays on said display unit instructions for
registering another finger when said average number of pseudo
minutiae exceeds said threshold, selects a finger having the
minimum average number of pseudo minutiae as the best finger when
the average number of pseudo minutiae of all fingers exceeds said
threshold, and registers the fingerprint of said best finger in
said registering unit.
6. A fingerprint registering method for a system to release a lock
by checking an affixed fingerprint with a registered fingerprint,
in which fingerprints of a prescribed number of at least two
supervisors are registered in a fingerprint registering unit by
using a fingerprint registering key, and a person who is next to
register a fingerprint registers the fingerprint in said
fingerprint registering device by means of the fingerprint
registering key and the matching of the fingerprint of at least one
of said prescribed number of supervisors who have registered their
fingerprints.
7. The fingerprint registering method according to claim 6, wherein
when the fingerprint is registered in said fingerprint registering
device, an attribute defining an accessible range of persons who
register fingerprints is also registered, the fingerprints or said
attribute registered in said fingerprint registering device can be
renewed or deleted by means of the fingerprint registering key and
the registration permission by matching of the fingerprints of said
supervisors who have registered their fingerprints.
8. The fingerprint registering method according to claim 6 to 7,
wherein when the registered fingerprints of said supervisors are
required to be deleted or the attribute is required to be changed,
said deletion requirement or the attribute change requirement is
rejected if the deletion or the attribute change results in that
the remaining number of supervisors who have registered
fingerprints becomes one or below the prescribed number.
9. A fingerprint checking entrance/exit control system for
unlocking by checking an affixed fingerprint and a registered
fingerprint comprising: a fingerprint registering device for
registering a fingerprint and an attribute of a fingerprint
registering person, a fingerprint checking unit for checking the
fingerprints registered in said fingerprint registering device with
the affixed fingerprint, a fingerprinting unit, and fingerprint
checking gates containing a control unit for controlling to unlock
according to said attribute and the result obtained by checking the
fingerprint affixed on said fingerprinting unit and the fingerprint
registered in said fingerprint registering device, wherein said
fingerprint registering device registers a fingerprint by
fingerprint registering operation by means of a fingerprint
registering key and the allowance of registering by checking of the
fingerprint of at least one supervisor.
10. The fingerprint checking entrance/exit control system according
to claim 9, wherein the functions of said fingerprint registering
device are provided on at least one of said fingerprint checking
gates to share the structure of at least fingerprinting unit.
11. A fingerprint checking method for binarizing a multivalued
image obtained by picturing an affixed fingerprint into a binarized
image, dividing said binarized image into a plurality of blocks,
determining the direction of ridge lines in respective blocks,
effecting spatial filtering of said multivalued image along the
ridge line direction, and binarizing to extract minutiae, wherein
respective picture elements in said respective blocks are detected
by using a direction detecting mask to find to which of a plurality
of directions they belong, the number of picture elements in each
of said plurality of directions is determined, the number of
picture elements in said respective directions is converted into a
vector, the maximum value in values obtained by adding respective
direction components on respective vectors is detected, and a
direction corresponding to the vector showing said maximum value is
judged to be the ridge line direction of said block.
12. The fingerprint checking method according to claim 11, wherein
after detecting the ridge line direction of said each block, the
average in the ridge line direction of a focused block and a
plurality of blocks around said focused block is determined to
judge as the ridge line direction of said focused block.
13. A fingerprint checking method which registers fingerprint data
derived from extraction of minutiae from a fingerprint, checks said
registered fingerprint data with fingerprint data for checking an
affixed fingerprint, and authenticates personal identification if
they match, wherein a conversion key number is produced by a
previously defined function from an entered key number and the
content at a prescribed byte in said registered fingerprint data,
said conversion key number is inserted for storing at a prescribed
byte in said registered fingerprint data, and a key number entered
at the time of checking the fingerprint is checked with a key
number reconstructed from said conversion key number inserted at
the prescribed byte of said registered fingerprint data, and the
checking fingerprint data obtained from the affixed fingerprint is
checked with said registered fingerprint data.
14. The fingerprint checking method according to claim 13, wherein
said entered key number and the content at the n-th byte of said
registered fingerprint data are added or subtracted to produce a
conversion key number, said conversion key number is inserted at
the m-th byte of said registered fingerprint data to store in a
file, the content at said n-th byte is subtracted or added with
respect to said conversion key number inserted at the m-th byte in
said registered fingerprint data at checking the fingerprint to
reconstruct the key number, and said reconstructed key number is
checked with the entered key number.
15. A fingerprint checking entrance/exit control system comprising
a host device which has a file for storing personal information
containing an identification number and entrance allowing
information and registered fingerprint data in a corresponded form
and a gate which has a fingerprint checking unit for storing said
personal information and said registered fingerprint data
downloaded from the file in said host device and checking with an
affixed fingerprint, both connected through a line, wherein the
fingerprint checking unit of said gate is provided with a control
unit which renews said registered fingerprint data with a time
stamp added to said affixed fingerprint data when personal
identification is authenticated by checking said affixed
fingerprint with said registered fingerprint data, and said host
device collects the renewed registered fingerprint data with the
time stamp added of said gate, renews the registered fingerprint
data and sends said renewed registered fingerprint data to a gate
which is in compliance with entrance allowance information of said
personal information.
16. The fingerprint checking entrance/exit control system according
to claim 15, wherein said host device has a file which stores first
and second registered fingerprint data from a finger registering
unit, and a control processing unit, when said second registered
fingerprint data is renewed by the latest renewed registered
fingerprint data collected from said gate, renews said first
registered fingerprint data by said second registered fingerprint
data, and transfers said renewed second registered fingerprint data
to a gate which is in compliance with said entrance allowing
information.
17. A fingerprint checking device for checking an affixed
fingerprint on a fingerprinting unit with registered fingerprint
data in correspondence with normal identification numbers stored in
a file, characterized by comprising: a local ID file which
allocates a local identification number having the less number of
digits than said normal identification numbers and stores said
local identification number, and a control unit which reads from
said file said registered fingerprint data corresponding to said
local identification number entered at the time of checking the
fingerprint and checks with said affixed fingerprint.
18. The fingerprint checking device according to claim 17, wherein
said local ID file stores said local identification number and
effective time information which indicates effective time of said
local identification number in a corresponded form.
19. The fingerprint checking device according to claim 17 or 18,
wherein said control unit allocates a local identification number
which does not overlap with another local identification number
registered in said local ID file, and corresponds said registered
fingerprint data, which is corresponded with said normal
identification number, with said local identification number.
20. A fingerprint registering method which binarizes multivalued
image data obtained by picturing an affixed fingerprint,
thinning-processing a binarized image resulting from said
binarizing process, extracts minutiae based on the
thinning-processed image data through said thinning processing,
deletes pseudo minutiae from said minutiae, and when the remaining
number of minutiae is equal to or above a prescribed number,
registers a fingerprint having minutiae according to said binarized
image data, wherein if the fingerprint registering in said process
for the first time fails, spatial filtering is effected on said
multivalued image data to continue in the ridge line direction in
the fingerprint registering process by said process for the second
time and following, said spatial filtered multivalued image data is
binarized and thinning-processed, said minutiae are extracted from
said thinning-processed image data, said pseudo minutiae are
deleted from said minutiae, and if the remaining number of minutiae
is equal to or more than a prescribed number, the fingerprint
having minutiae according to said binarized image data is
registered.
21. The fingerprint registering method according to claim 20,
wherein to delete said pseudo minutiae, when the extracted minutiae
are within a prescribed area, they are judged as pseudo minutiae,
and said pseudo minutiae are deleted from a list of minutiae.
Description
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates to a fingerprint registering
method for registering a fingerprint by judging whether or not it
has been registered and to a fingerprint checking device.
[0003] The present invention relates to a fingerprint registering
method with security improved and to a fingerprint checking
entrance/exit control system.
[0004] The present invention relates to a fingerprint checking
method for extracting a fingerprint in the direction of ridge lines
in registering and checking the fingerprint.
[0005] The present invention relates to a fingerprint checking
method for checking a registered fingerprint and an affixed
fingerprint to authenticate personal identification.
[0006] The present invention relates to a fingerprint checking
entrance/exit control system for checking an affixed fingerprint
and a registered fingerprint to control the permission or not of
entrance.
[0007] The present invention relates to a fingerprint checking
device for checking a registered fingerprint and an affixed
fingerprint.
[0008] The present invention relates to a fingerprint registering
method for a fingerprint checking device.
[0009] 2. Prior Art
[0010] Fingerprint checking devices which check a registered
fingerprint with an affixed fingerprint to authenticate personal
identification have been put into practical use. And, the
fingerprint checking devices are desired to easily register
fingerprints with reliability.
[0011] As shown in FIG. 30, a conventional way of registering
fingerprints judges whether or not fingerprinting for a fingerprint
image pickup is for the first time (D1), if it is its first time,
temporarily registers it (D2), if not its first time, judges
whether or not it is the second time (D3), if it is its second time
of fingerprinting, checks the temporarily registered fingerprint
with the second affixed fingerprint (D4), judges whether or not
they match (D5), if they match, formally registers (D6), and
terminates normally. And, if they do not match, it is concluded as
registration failure. In this case, registration processing can be
repeated on another finger.
[0012] After binarizing a fingerprint shown in FIG. 31(A), it is
thinning-processed as shown in (B), and a registering window in a
square frame is enlarged as shown in (C). In (C), N indicates a
normal minutia, and P1 to P4 indicate pseudo minutiae. For example,
a bifurcation point having a bifurcation length of a prescribed
length of a ridge line and an ending point having a space of a
prescribed length or more are determined as normal minutia, and a
bifurcation point and an ending point under other conditions are
determined as pseudo minutia.
[0013] In the above-described temporary registering and formal
registering, registering windows each consisting of, for example,
36.times.30 picture elements with normal minutia N at almost the
center is selected in the number of about 15 for example from a
single fingerprint image and registered as shown in FIG. 31(C).
[0014] Since fingerprints do not change, they are suitable for
authenticating personal identification. And, a registered
fingerprint and an affixed fingerprint are checked by a fingerprint
checking device, and when they match, the pertinent fingerprint is
judged as of a registered person. But, the fingerprint image
pictured by a fingerprint image pickup unit changes largely
depending on chaps, wrinkles, dirt and a fingerprinting pressure of
a finger tip. Therefore, checking immediately after the temporary
registering mostly results in matching, but there is a disadvantage
that a matching rate is lowered sharply with a lapse of time.
[0015] FIG. 32 and FIG. 33 are explanatory diagrams of fingerprint
images and thinning-processed images. (A) in the respective
drawings shows pictured fingerprint images, and (B) shows images
obtained by binarizing and thinning processing, and rectangles
indicate registering windows. In FIG. 32, the fingerprint image is
relatively good, and normal minutiae are easily extracted as shown
in (B). But, in FIG. 33, the fingerprint has chaps and many pseudo
minutiae as shown in (B), so that it is not easy to select
registering windows.
[0016] The fingerprint shown in FIG. 33 is formally registered
because it has a high possibility of matching when it is checked
with a registered fingerprint immediately after the temporary
registering. But, the states of chaps and wrinkles change with a
lapse of time, and a match rate is sharply lowered accordingly. To
avoid it, it is desirable to obtain a fingerprint image with good
image quality as shown in FIG. 32, but it is hard to judge whether
or not the fingerprint image is good at the time of registering a
fingerprint excepting when the fingerprint image is heavily
deteriorated such that mismatching results. Therefore, even when
another finger is used to register a fingerprint in case of
mismatching, it is impossible to judge which finger is best.
[0017] On the other hand, there is a known fingerprint checking
entrance/exit control system which authenticates personal
identification by fingerprint checking to allow the entrance or
exit. It is demanded to improve the security of fingerprint
registration in such a system.
[0018] FIG. 34 is an explanatory diagram of a system, in which
reference numeral 261 denotes a fingerprint registering device, 262
a fingerprint checking unit consisting of a host computer, 263 a
modem, 264 a private branch exchange (PBX), 265-1 to 265-n rooms
such as an office, a computer room and a vault, 266-1 to 266-n
fingerprint checking gates, and 267-1 to 267-n electric locks.
[0019] The electric locks 267-1 to 267-n are for unlocking the
doors to the rooms 265-1 to 265-n, and the fingerprint checking
gates 266-1 to 266-n are provided to correspond to the rooms 265-1
to 265-n and connected to the fingerprint checking unit through the
private branch exchange 264. And, in a case of a small-scale
fingerprint checking entrance/exit control system, the private
branch exchange 264 and the modem 263 may be omitted, and the
fingerprint checking gates 266-1 to 266-n and the fingerprint
checking unit 262 can be connected by an LAN or the like.
[0020] The fingerprint checking gates 266-1 to 266-n each have a
fingerprinting part, and read the affixed fingerprint to transfer
to the fingerprint checking unit 262. The fingerprint checking unit
262 checks the fingers registered in the fingerprint registering
device 261 with the transferred fingerprint, and transfers the
checked result to the fingerprint checking gates through the
private branch exchange 264. Otherwise, the fingerprint data
registered in the fingerprint registering device 261 is transferred
to the fingerprint checking gates 266-1 to 266-n to store in a
storage device (not shown), a fingerprint checking unit similar to
the fingerprint checking unit 262 is provided at the respective
fingerprint checking gates 266-1 to 266-n, and the registered
fingerprints can be checked with the affixed fingerprint at the
respective fingerprint checking gates 266-1 to 266-n.
[0021] And, when the registered fingerprint matches with the
affixed fingerprint, the fingerprint checking gate unlocks the
electric lock to allow entrance, but when they do not match, the
electric lock is not unlocked to prohibit the entrance. And, when
the use of a computer is allowed by fingerprint checking, the
computer can be used when the registered fingerprint matches with
the affixed fingerprint and the electric lock is unlocked.
[0022] Therefore, a person who has registered his or her
fingerprint can enter a room or use a computer without using an
ordinary key when personal identification is authenticated by
fingerprint checking. In such a case, by registering a fingerprint
and a room as a pair, only specified persons are allowed to enter a
specified room. And, it is possible to register a specified person
to enter every room.
[0023] By registering the fingerprints of persons allowed to enter
a room in the fingerprint registering device 261, only fingerprint
registered persons can enter the room. To register a fingerprint,
it is often that registering is permitted according to a password,
or registering is allowed by using a registering key.
[0024] But, it is highly possible that a password is used by
stealth unless its number of digits is increased, but when the
number of digits is increased, it is troublesome to enter the
password. And, in the case of using the registering key, there is a
disadvantage that any person can register his or her fingerprint by
using the registering key. Accordingly, the security of entrance to
or exit from a room after registering a fingerprint can be retained
fully, but the security at the time of registering a fingerprint is
not sufficient. And, fingerprint checking to authenticate personal
identification is to check an affixed fingerprint with a previously
registered fingerprint, and it is generally configured that to
register a fingerprint, minutiae of a fingerprint image obtained by
picturing an affixed fingerprint are extracted as registered
fingerprint data, the registered fingerprint data is stored in a
file, and the affixed fingerprint image is binarized at the time of
fingerprint checking and checked with the registered fingerprint
data read from the file. To extract the minutiae, the fingerprint
image is required to accurately show the ridge lines of the
fingerprint, and various types of image processing methods have
been proposed.
[0025] FIG. 35 is an explanatory view of a fingerprint checking
device, in which reference 311 denotes a fingerprint image pickup
unit, 312 a multivalued image capturing unit, 313 a fingerprinting
judging unit, 314 a ridge line direction detecting unit, 315 a
spatial filter, 316 a binarizing unit, 317 a minutia extracting
unit, 318 a registering unit, and 319 a checking unit. The
fingerprint image pickup unit 311 takes a picture of an affixed
fingerprint by a CCD camera, the multivalued image capturing unit
312 converts an analog image into a multivalued digital image and
stores in an image memory (not shown), and the fingerprinting
judging unit 313 judges whether or not a fingerprint has been
affixed based on the multivalued image.
[0026] At the time of registering a fingerprint, the fingerprint is
affixed and pictured by the fingerprint image pickup unit 311, and
captured as a multivalued image by the multivalued image capturing
unit 312. Based on the multivalued image, it is judged by the
fingerprinting judging unit 313 whether fingerprinting has been
made or not, and when it is judged as fingerprinting, the
multivalued image is binarized by the ridge line direction
detecting unit 314. For example, with 16.times.16 picture elements
as one block, division into respective blocks is made, the ridge
line direction is detected for each block, and conversion into the
multivalued image is made by the spatial filter 315. The spatial
filter 315 determines a luminance average value of focused picture
elements and multiple picture elements in the ridge line direction
on a multivalued image captured by the multivalued image capturing
unit 312, for example, and processing of determining the luminance
of the focused picture element can be made with respect to the
blocks.
[0027] The multivalued image processed by the spatial filter 315 is
binarized in the binarizing unit 316, and based on the binarized
image, minutiae such as bifurcation points of ridge lines are
extracted in a prescribed number by the minutia extracting unit,
and data containing the minutiae is stored as registered
fingerprint data in the registering unit 318.
[0028] In checking a fingerprint, the fingerprint is affixed and
pictured by the fingerprint image pickup unit 311, and captured as
a multivalued image by the multivalued image capturing unit 312.
Based on the multivalued image, it is judged by the fingerprinting
judging unit 313 whether fingerprinting has been made or not, and
when it is judged as fingerprinting, the multivalued image is
binarized by the binarizing unit 316, the binarized image of
fingerprint is checked with the registered fingerprint data read
from the registering unit 318 by the checking unit 319, and a
checked result output signal on matching or mismatching is sent to
an unillustrated gate having an electric lock.
[0029] FIG. 36 is an explanatory diagram of dividing a pictured
image into blocks, and when 512.times.512 picture elements are
determined as one screen, division into 1024 blocks is made with
16.times.16 picture elements as one block, for example. And,
P.sub.1.1.about.P.sub.1.256 denote the picture elements in the top
left block, and P..sub.1024.1.about.P.sub.1024.256 denote the
picture elements in the right bottom.
[0030] FIG. 37 is an explanatory diagram of judging the direction
of picture elements. In the ridge line direction detecting unit 314
shown in FIG. 35, using a 3.times.3 picture element direction
detecting mask and a pattern with its center as the focused picture
element, the directions of the focused picture elements are
determined as shown in D1 to D8. For example, pattern 1-1 and
pattern 1-2 are judged as the same horizontal direction D1, and
pattern 3-1 and pattern 3-2 are judged as the same 45-degree
direction D3. And, if not belonging to 16 types of direction
detecting mask patterns shown in FIG. 37, the direction of focused
picture elements does not belong to any pattern. Therefore, the
focused picture elements can be judged to belong to which of the
eight directions D1 to D8 in this case, they will be one of eight
directions indicated by 1 to 8 at right bottom of the drawing. And,
each block is determined to have a direction that the number of
picture elements in every direction in the block is maximum as the
ridge line direction of the pertinent block.
[0031] FIG. 38 is a flowchart of a conventional example, in which a
block number is initialized with m=1 (B-1). In other words, number
m for 1 to 1024 is allocated with respect to 1024 blocks in the
image shown in FIG. 36, and the block number m is determined as 1
for initialization. Then, with n=1 (B2), the picture element number
n in the block is initialized. In other words, the number n for 256
picture elements in the image shown in FIG. 36 is allocated, and
this picture element number n is determined as 1 for
initialization.
[0032] Then, contents V1 to V8 of a totaling register for totaling
the number of picture elements corresponding to respective
directions 1 to 8 shown at the lower right of FIG. 37 are cleared
to zero and initialized (B3). And, the direction of picture element
P.sub.m.n (m=1.about.1024, n=1.about.256) is detected by using a
direction detecting mask as described in connection with FIG. 37,
+1 is added to Vx (x=1.about.8) corresponding to a matched
direction (B4). And, it is judged whether or not n=256 (B5), and if
n is not equal to 256, it is determined as n=n+1 (B6), then
processing goes to step (B4). The above-described steps (B2) to
(B6) correspond to histogram generation processing according to the
direction in the block.
[0033] When n=256, processing on one block is completed, and it is
determined as i=1 (B7), register No. i according to the direction
is initialized, it is determined as Sm=0 (B8), and a direction
component maximum value Sm is initialized. And, totaling register
Vi and the maximum value Sm are compared to judge whether Sm<Vi
(B9), and when Sm<Vi, it is determined as Sm=Vi (B10), and Dm=i
(B11). In other words, the totaling register Vi is determined as
the maximum value Sm, and direction No. i of the totaling register
Vi is determined as direction No. Dm of the maximum value Sm.
[0034] When Sm is not smaller than Vi, or after step (B11), it is
judged whether or not i=8 (B12). In other words, it is judged
whether or not processing has been made on eight directions, and
when i is not equal to 8, it is determined as i=i+1 (B14), and
processing goes to step (B5). And, when i=8, it is judged whether
or not m=1024 (B13). Namely, it is judged whether or not processing
on all blocks has been completed, and if not completed, it is
determined as m=m+1 (B15). And, block No. m is determined as an
increment, and processing goes to step (B2). Therefore, at the end
of processing, the maximum value Sm of the direction component of
respective blocks is stored in a direction component maximum value
storage register corresponding to block Nos. 1 to 1024, and
direction No. Dm is stored in a direction storage register
corresponding to block Nos. 1 to 1024.
[0035] FIG. 39 and FIG. 40 are explanatory diagrams of detecting a
ridge line direction in a conventional example. In FIG. 39, (A)
shows a schematic view of a multivalued image of a pictured
fingerprint, and (B) shows a schematic view of a binarized image
obtained by binarizing the multivalued image. Based on the
binarized image, detection in the ridge line direction on each
block described above results in (C). Based on the result detected
in the ridge line direction of each block, the multivalued image
shown in (A) is subject to the above-described spatial filtering,
and the result is shown in FIG. 40(D). It is apparent by comparing
the multivalued image of (D) and the multivalued image of FIG.
39(A) that chapped portions are connected. Therefore, when the
multivalued image of (D) is binarized, it is changed as shown in
(E). When the binarized image of (E) is compared with the binarized
image of FIG. 39(B), it is apparent that the binarized image of (E)
is clear.
[0036] In detecting the direction of ridge lines of a fingerprint
in the conventional example, the direction of each picture element
in the block is detected, the number of picture elements
corresponding to the direction in the block is determined, and the
direction that the number of picture elements becomes maximum is
determined as the ridge line direction in the block. And, as to the
directions that the number of picture elements is same, one of them
is selected. Therefore, when the number of picture elements is same
in directions which are intersecting at right angles and one of
them is selected, there is a disadvantage of having a possibility
that the direction becomes opposite from the flow of the ridge
lines. In other words, there is a disadvantage that the ridge line
direction not complying with the flow of the ridge lines of the
peripheral blocks is detected.
[0037] For example, as shown in FIG. 41(A), in the ridge line
direction pattern of each block, when a ridge line direction not
complying with the flow of the ridge lines of the peripheral blocks
is obtained like a block indicated by 321, it is changed by the
spatial filtering to a multivalued image which is schematically
shown in (B), then it is converted into a binarized image which is
schematically shown in (C), and a bridge is produced between the
ridge lines at a portion indicated by 322 which corresponds to the
block 321. Therefore, there is a disadvantage that an error occurs
when minutiae are extracted.
[0038] And, a system has been put into practical use which checks a
registered fingerprint with an affixed fingerprint, and if they
match, unlocks a door to allow the entrance or allows to operate
equipment. By checking fingerprints, security can be improved as
compared with the use of a physical key. In such a case, it is
necessary to manage the registered fingerprints with reliability
and to prevent misuse such as alteration of the registered
fingerprints.
[0039] FIG. 42 is an explanatory diagram of a fingerprint checking
system, in which reference numeral 411 denotes a fingerprint
checking device, 412 a fingerprint reading unit, 413 a control
unit, 414 a storage unit for storing registered fingerprint data,
420 a host computer, 421 a processor (CPU), 422 a bus, 423 a random
access memory (RAM), 424 a read-only memory (ROM) for storing data
or the like, 425 a hard disk drive (HDD) for storing a large volume
of registered fingerprint data, 425a registered fingerprint data,
425b a data destruction checking code, 426 and 427 an interface
(IF), 430 a card reader, and 431 an IC card for keeping registered
fingerprint data.
[0040] The host computer 420 can be a personal computer, and the
hard disk drive 425, which is now relatively inexpensive and small,
has a large capacity and can store a large volume of fingerprint
data. The storage unit 414 in the fingerprint checking device 411
is a programmable read-only memory (EEPROM, flash memory, etc.) and
can store registered fingerprint data for scores of people or
several hundred people. And, if necessary, the registered
fingerprint data stored in the hard disk device 425 in the host
computer 420 can be downloaded to the storage unit 414.
[0041] To check fingerprints in the fingerprint checking device
411, an identification number (ID) is entered. To enter the
identification number, a keyboard or a ten-key which is not
illustrated can be used, or a medium such as an ID card which
stores an identification number (ID) can be used. And, registered
fingerprint data corresponding to the identification number is read
from the storage unit 414, the registered fingerprint data is
compared with the fingerprint data of an affixed fingerprint read
by the fingerprint reading unit 412 by the control unit 413, and if
they match, control of unlocking or the like is made according to
an output signal from the control unit 413.
[0042] It is also possible to store the registered fingerprint data
in the IC card 431. By reading the IC card 431 by the card reader
430, the registered fingerprint data can be transferred to the
fingerprint checking device 411 through the host computer 420 and
checked with data of an affixed fingerprint. The registered
fingerprint data is configured by taking a picture of the affixed
fingerprint, binarizing it, extracting a plurality of minutiae such
as bifurcation points owing to the ridge lines of the fingerprint,
determining each minutia as made of multiple picture elements, and
using binarized data rows of the respective minutiae.
[0043] To check that data in a file having the registered
fingerprint data is not destroyed, the data destruction checking
code 425b is added to the registered fingerprint data 425a. By this
data destruction checking code 425b, a total value, exclusive-OR or
scrambled value of generating polynominal is used for all data
contained in the file, and if the data stored in the file is
changed even by one bit, this one bit change can be detected based
on the data destruction checking code 425b. But, if the contents of
the file are totally exchanged, detection cannot be made.
[0044] As shown in FIG. 42, the registered fingerprint data is
stored in the storage unit 414 of the fingerprint checking device
411, stored in the hard disk drive 425 in the host computer 420
connected to the fingerprint checking device 411, or stored in a
medium such as the IC card 431 or an optical card using a
magneto-optical record medium.
[0045] Where the registered fingerprint data is stored in the
fingerprint checking device 411, and if it is exchanged with
another fingerprint checking device having other fingerprints
stored according to the identification number identical to the
identification number (ID) stored in the formal fingerprint
checking device, all operation on the system side is not different,
the registered fingerprint data is exchanged, and if another
fingerprint is affixed using the same identification number (ID) as
before, checking results in matching.
[0046] Where the fingerprint data is stored in the hard disk derive
425 in the host computer 420, the data file in the hard disk drive
can generally be operated freely. For example, the registered
fingerprint data file can be replaced by another file having
different data with the same file name. Therefore, if some person
who is not formally registered attempts to register his or her
fingerprint in another system and the registered fingerprint data
is reloaded by such registered fingerprint data, a person who is
not formally registered can use the system illegally.
[0047] Where the registered fingerprint data is stored in a
portable medium such as an IC card or optical card, the registered
fingerprint data can be reloaded, so that misuse can be made in the
same way as described above.
[0048] Accordingly, it is thought to insert a key number with
respect to respective registered fingerprint data. The key number
is inserted at a given byte of the registered fingerprint data, the
byte number and the key number are made confidential, and the key
number is stored so that the formally registered persons are not
revealed. Even if the registered fingerprint data is exchanged,
misuse cannot be made because the key numbers of the formally
registered persons are also changed. But, as shown in FIG. 43, if
the same key number is used to repeatedly register fingerprints,
registered fingerprint data A, B and C become different owing to
the positional change of minutiae and change of data rows of
minutiae.
[0049] Accordingly, when registered fingerprint data A, B and C are
read from the registered fingerprint data storage file and checked,
the key number at the x-th byte from the leading address of
respective registered fingerprint data A, B and C matches, and
other areas do not match because they have a random property. In
other words, it can be identified that the x-th byte where matching
is obtained is where the key number is inserted. Thus, the key
number can be read from the registered fingerprint data of the
formally registered persons, so that misuse can be made.
[0050] And, a fingerprint checking entrance/exit control system has
been proposed to authenticate personal identification by checking
fingerprints, thereby allowing the entrance to a predetermined room
or the like. And, such a fingerprint checking entrance/exit control
system is desired to have an improved fingerprint checking
accuracy.
[0051] FIG. 44 is an explanatory diagram of a fingerprint checking
entrance/exit control system, in which a host device 531, a
plurality of gates 532-1 to 532-n, and a given number of
fingerprint registering devices 537-1 to 537-m are connected by a
line 533 of a local area network (LAN), the respective gates 532-1
to 532-n have fingerprint checking units 540-1 to 540-n and
electric locks 541-1 to 541-n, an affixed fingerprint is checked
with the registered fingerprints in the fingerprint checking unit,
and when personal identification is authenticated, an unlocking
signal is given to the electric lock to release it. And, reference
numeral 534 denotes a fingerprint registering unit, 535 a control
unit, 536 a printer for outputting a list of registered persons, a
list of setting or the like, 538-1 to 538-m control units, and
539-1 to 539-m fingerprint registering units.
[0052] To register a fingerprint by the fingerprint registering
units 534, 539-1 to 539-m, personal information containing entrance
allowing information such as name, identification number, post and
room number in which he or she wants to enter is entered. The
personal information and registered fingerprint data are stored in
a file (not shown) in the host device 531. And, the personal
information and registered fingerprint data are downloaded to the
gate in conformity with the entrance allowing information. In this
case, desired registered fingerprint data can be downloaded
according to the demand from the gate.
[0053] When personal identification is authenticated by checking
the registered fingerprint data with the affixed fingerprint, it is
known that the registered fingerprint data is renewed by the
affixed fingerprint data, and the registered fingerprint data is
controlled as if it is obtained by the latest fingerprint
registering operation. And, it is known that when first and second
registered fingerprint data are stored, the affixed fingerprint is
checked with the first registered fingerprint data and personal
identification cannot be authenticated, the affixed fingerprint is
checked with the second registered fingerprint data, and if
personal identification cannot be authenticated yet, it is
determined as a mismatch; but if personal identification can be
authenticated, the second registered fingerprint data is renewed by
the affixed fingerprint data (e.g., Japanese Patent Laid-Open
Publication No. Sho 63-301376). By such a method, the probability
of authenticating personal identification by the second fingerprint
checking is improved, and the registered fingerprint data is
renewed when the personal identification is authenticated, so that
the latest registered fingerprint data can be used to check
fingerprints.
[0054] As described above, the fingerprint checking entrance/exit
control system is generally provided with the fingerprint checking
units 540-1 to 540-n in the respective gates 532-1 to 532-n to
check the fingerprints in a distributed manner. Therefore, when the
above-described registered fingerprint data is renewed at the
respective gates 532-1 to 532-n, the registered fingerprint data at
the gate with a high frequency of use becomes the latest
fingerprint data, a mismatch of the renewed registered fingerprint
data at the respective gates occurs depending on the frequency of
use, and the accuracy of authenticating personal identification is
variable depending on the gates.
[0055] And, the fingerprint data stored in the host device 531 is
the first one at the time of registering the fingerprint, and when
entering a room after a long period since the fingerprint was
registered in a gate determined according to the entrance allowing
information, the registered fingerprint data is downloaded from the
host device 531. But, since the fingerprint data is not latest, it
is highly possible that checking results in a mismatch. Since it is
thought that the fingerprint is one and only and not variable, it
is used to authenticate personal identification, but it changes to
some extent, and a state of the fingerprint face or the
fingerprinted position varies every time fingerprinting is made,
but the fingerprint data at the time of registering fingerprints is
not always optimum. Therefore, by using the affixed fingerprint
data with the conditions according to which personal identification
can be authenticated at every fingerprinting for the next time, the
checking probability can be improved, but as described above, there
is a disadvantage that the registered fingerprint data not renewed
is remained in the host device 531.
[0056] And, a fingerprint checking device has been put in practical
use which configures a file with the identification number entered
at the registration of fingerprints and the registered fingerprint
data corresponded, and checks the registered fingerprint data read
from the file based on the identification number entered for
checking fingerprints with the affixed fingerprint to authenticate
personal identification. And, improvement of operability of such a
fingerprint checking device is demanded.
[0057] A system is known to control entrance /exit by checking
fingerprints, and to register a fingerprint, personal information
such as identification number, name, post, attribute and desired
room number is entered, and a fingerprint is affixed. And, to enter
a room, identification number is entered into the fingerprint
checking device, and a fingerprint is affixed. The fingerprint
checking device reads the registered fingerprint data from a file
according to the entered identification number, checks it with the
affixed fingerprint to authenticate personal identification, and if
personal identification can be authenticated, releases the electric
lock of the door to allow to enter.
[0058] Identification numbers for various systems are allocated
without overlapping. For example, when a single fingerprint
checking device in the entrance/exit control system can register
fingerprints for 480 persons, by providing 32 fingerprint checking
devices, in other words, if there is 32 rooms, 15360 persons can
register a fingerprint. And, to allocate the identification number
to these 15360 persons without overlapping, at least five digits
are required. And, a larger-scaled entrance/exit control system may
need the identification number of six digits or more.
[0059] Therefore, to enter a room, an identification number of five
digits or six digits must be entered into the fingerprint checking
device. Even if a fingerprint can be checked in a short time, the
entrance of an identification number takes a long time, and the
fingerprint checking device for a room where entrance and exit are
frequent is particularly poor in operability.
[0060] And, the fingerprint checking device checks the previously
registered fingerprints with a newly affixed fingerprint to
authenticate personal identification, and the registered
fingerprint is made by storing an area containing respective
minutiae corresponding to a plurality of minutiae in multivalued
image data obtained from a pictured fingerprint into a registration
file. And, the binarized image data obtained by picturing an
affixed fingerprint at checking the fingerprint is compared with
respective areas of the binarized image data containing the
minutiae read from the registration file, and if areas in
prescribed number or more match, it is determined as a match.
Accordingly, to improve the fingerprint checking accuracy, it is
demanded to register fingerprints having a desired accuracy.
[0061] The fingerprint has two minutiae of an ending point and a
bifurcation point of ridge lines, and most of fingerprint checking
devices store the minutiae as registration data in the registration
file. For the fingerprint registration, the multivalued image data
obtained by picturing an affixed fingerprint is binarized, the
binarized image data is thinning-processed, the ridge lines
thinning-processed are extracted with the ending points and the
bifurcation points as the minutiae, the binarized image data areas
are cut out according to coordinate information of the minutiae,
and they are stored as the registered data in the registration
file.
[0062] FIG. 45 is an explanatory diagram of a fingerprint checking
device, in which reference numeral 601 denotes an affixed
fingerprint image pickup unit, 602 a data processing unit, 603 a
bus, 604 a processor (CPU), 605 an interface (IF), 606 a read-only
memory (ROM) storing a program, 607 a multivalued image memory, 608
a binarized image memory, 609 a binarized image save memory, 610 a
thinning-processed image memory, 611 a minutia list memory, and 612
a nonvolatile memory for registered data. The processor 604
controls the respective units connected through a bus 603 and has a
function of processing the image data.
[0063] The affixed fingerprint image pickup unit 601 comprises a
fingerprinting stand on which a fingerprint is affixed, a lighting
source, a CCD camera, a display, and an input operation unit such
as a ten-key which are unillustrated. To register a fingerprint,
information of an ID number and a password and a fingerprint
registering request are entered through the input operation unit, a
fingerprint is affixed onto the fingerprinting stand, and the
affixed fingerprint is pictured by the CCD camera. A signal of the
fingerprint image pictured by the affixed fingerprint image pickup
unit 601 is A/D converted by the interface 605 into multivalued
image data.
[0064] The memories 607 to 611 in the data processing unit 607 are
cleared by initializing. And, the multivalued image data which was
A/D-converted by the interface 605 is written into the multivalued
image memory 607, the multivalued image data in the multivalued
image memory 607 is binarized by the data processing function of
the processor 604 and written into the binarized image memory
608.
[0065] The binarized image data in the binarized image memory 608
is copied and saved into the binarized image data save memory 609.
And, the content of the binarized image memory 608 is subjected to
thinning processing. In other words, the ridge lines of the
fingerprint are changed into thin lines. The thinning-processed
image data is written into the thinning-processed image memory 610.
Based on the thinning-processed image data in the
thinning-processed image memory 610, the minutiae of the ending
points and bifurcation points are extracted, and coordinate
information of the minutiae is written into the minutia list memory
611. When the number of minutiae is a prescribed number or more,
images of minutiae are cut out of the binarized image save memory
and stored into the nonvolatile memory 612 for registration data
together with an ID number and a password.
[0066] To check a fingerprint, an ID number and a password are
entered through the input operation unit of the affixed fingerprint
image pickup unit 601, the fingerprint is affixed, and it is
pictured. The fingerprint image signal is stored in the multivalued
image memory 607 as multivalued image data in the same way as
registering a fingerprint. And, the processor 604 examines the
entered ID number and password, and if normal, the registered
fingerprints are read from the nonvolatile memory 612 for
registering, and based on the registered fingerprint in an area
containing the minutiae, checked with the entered fingerprint, and
if the number of matched points is equal to or more than a
prescribed number, it is determined that personal identification
was authenticated.
[0067] FIG. 46 is an explanatory view of a binarized image of a
fingerprint, which is obtained by digitizing the analog image
signal of the affixed fingerprint pictured, the multivalued image
data is temporarily stored in the multivalued image memory 607 as
described above, and the multivalued image data is binarized. In
the binarized image state, since it is not easy to extract the
ending point a or the bifurcation point b, the ridge lines are
changed into thin lines. FIG. 47 shows an image having thin lines,
and the ending point a and the bifurcation point b can be extracted
easily by processing with a processor.
[0068] If the fingerprint image in the affixed fingerprint state is
not good, for example, if the ridge lines are seen in a separated
form despite that the ridge lines in the binarized image are
continuous as indicate by c in FIG. 48(A), when the minutiae are
extracted after thinning processing, the extraction is made with
such separated points as the ending points.
[0069] In this case, since the coordinates of the minutiae are
close, it is known to delete the minutiae, which are close in a
certain range or 0.5 mm or below, as pseudo minutiae from the
minutia list. Thus, the minutiae due to the separated points of the
ridge lines indicated by c in FIG. 48(A) are deleted as pseudo
minutiae.
[0070] When such pseudo minutiae are deleted, normal minutiae are
also deleted when they are mutually close, and the number of
minutiae to be registered in the minutia list is decreased. When
the binarized image of FIG. 48(A) is changed into thin lines and
the minutiae are extracted, the minutiae more than the extracted
number of minutiae of the relatively good binarized image as shown
in FIG. 46 can be extracted, but when pseudo minutiae are deleted,
the remaining minutiae are decreased, and a desired number of
minutiae may not be obtained. In registering a fingerprint, a
prescribed number or more of minutiae are required, so that the
registering process may fail by the pseudo minutia deleting
process, and registering is made again.
[0071] Accordingly, for a blurred fingerprint like the binarized
image of the fingerprint as shown in FIG. 48(A), it is known to
effect the spatial filtering to connect the minutiae of the ridge
lines. As a result, the binarized image as shown in FIG. 48(B) is
obtained. When the binarized image is changed into thin lines, the
normal minutiae only remain, and minutiae in a prescribed number or
more can be extracted.
[0072] For a blurred fingerprint, even when pseudo minutiae are
deleted by the spatial filtering, the number of normal minutiae
becomes a prescribed number or more, a failing possibility in the
registering process is lowered, and as compared with a case of
registering with the pseudo minutiae included, the checking rate in
fingerprint checking is improved. But, when the fingerprint image
has good quality and the spatial filtering is made, a possibility
of converting the pseudo minutiae into the normal minutiae is
high.
[0073] For example, the binarized image of the fingerprint shown in
FIG. 49(A) has relatively good quality, and when the spatial
filtering is made when there is a crack as indicated by d, the
binarized image shown in (B) is obtained, the crack indicated by d
in (A) is converted into a normal minutia as indicated by e in (B)
and registered.
[0074] FIG. 50(A) shows a multivalued image of a fingerprint having
large cracks, and (B) shows a multivalued image which has through
the spatial filtering, and f shows a state that cracks have
continued. And, when a fingerprint is checked, the spatial
filtering is not applied to the fingerprint image data to check
with the registered fingerprints, and the match rate of the
fingerprint is high when the normal minutiae having a crack are
registered than when the pseudo minutiae are registered, and it
becomes higher when the normal minutiae without any crack are
registered. In other words, there are cases that the match rate of
fingerprints can be improved by the spatial filter processing and
the match rate cannot be improved.
SUMMARY OF THE INVENTION
[0075] It is an object of the present invention to achieve the
reliability and simplicity of registering a fingerprint by
indicating the quality of a fingerprint image by the number of
pseudo minutiae.
[0076] It is another object of the present invention is to improve
security of a fingerprint checking entrance/exit control system in
registering a fingerprint.
[0077] It is still another object of the present invention to
detect the direction of ridge lines of a fingerprint accurately as
much as possible.
[0078] It is also another object of the present invention to
remarkably improve security in checking a fingerprint by remedying
various disadvantages.
[0079] It is another object of the present invention to collect
renewed registered fingerprint data by a host device and hold the
registered fingerprint data of each gate as the latest fingerprint
data.
[0080] It is another object of the present invention to improve the
operability by enabling to use identification numbers having the
number of less digits.
[0081] It is another object of the present invention to register a
fingerprint having a high match rate by automatically applying
spatial filtering in re-registering only.
[0082] A fingerprint registering method according to the present
invention detects normal minutiae and pseudo minutiae of a
fingerprint pictured by a fingerprint image pickup unit, counts the
pseudo minutiae in registering windows with the normal minutiae at
almost the center, determines the average number of pseudo minutiae
in registering windows from a total of pseudo minutiae in all
registering windows, and registers the fingerprint when the average
number of pseudo minutiae is equal to or below a threshold.
[0083] The fingerprint registering method according to the
invention, when the average number of pseudo minutiae in
registering windows exceeds the threshold, instructs to register
another fingerprint, and sequentially changes fingers to register
until a fingerprint with the average number of pseudo minutiae in
registering windows equal to or below the threshold is
obtained.
[0084] The fingerprint registering method according to the
invention, when the average number of pseudo minutiae in
registering windows exceeds the threshold, instructs to register
another fingerprint, selects a finger having the minimum average
number of pseudo minutiae as the best finger, and registers the
fingerprint of the best finger.
[0085] A fingerprint checking device according to the present
invention comprises a fingerprint image pickup unit, an image
processor unit for thinning processing a pictured image by the
fingerprint image pickup unit, a minutia detecting unit for
detecting normal minutiae and pseudo minutiae from the
thinning-processed image from the image processor unit, an average
pseudo minutia calculating unit for calculating the average number
of pseudo minutiae in all registering windows by counting the
pseudo minutiae in the registering windows with the normal minutiae
at almost the center, a registering unit for registering a
fingerprint, a judging unit for comparing the average number of
pseudo minutiae from the average pseudo minutia calculating unit
with a threshold to register the fingerprint in the registering
unit when the average number of minutiae is equal to or below the
threshold, a display unit for showing the average number of pseudo
minutiae from the average minutiae calculating unit or information
which corresponds to the average number of pseudo minutiae, and a
checking unit for checking the fingerprint registered in the
registering unit with the fingerprint pictured by the fingerprint
image pickup unit.
[0086] In the fingerprint registering method according to the
invention, the judging unit displays on the display unit
instructions for registering another finger when the average number
of pseudo minutiae exceeds the threshold, selects a finger having
the minimum average number of pseudo minutiae as the best finger
when the average number of pseudo minutiae of all fingers exceeds
the threshold, and registers the fingerprint of the best finger in
the registering unit.
[0087] In the fingerprint registering method according to the
present invention, the normal minutiae and pseudo minutiae of a
fingerprint are detected, and the pseudo minutiae in registering
windows with the normal minutiae at almost the center are counted.
And, the average number of pseudo minutiae in registering windows
is determined by totaling pseudo minutiae in all registering
windows and dividing the total by the number of registering
windows. When the average number of pseudo minutiae is smaller, the
quality of the fingerprint image is better, and when the average
number of pseudo minutiae is equal to or below the threshold, it is
judged that the pictured fingerprint image is good, and registering
is effected. In this case, the formal registering can be effected
after temporarily registering and checking by the second
fingerprinting.
[0088] In the fingerprint registering method according to the
invention, when the average number of pseudo minutiae in the
registering windows exceeds the threshold, it is indicated that the
quality of the fingerprint image is not good. Therefore, as to five
fingers for example, the fingerprint image pickup is repeated with
the fingers changed successively until the average number of pseudo
minutiae becomes equal to or below the threshold, and a finger
which has a good image quality can be registered.
[0089] In the fingerprint registering method according to the
invention, when fingerprint registering is sequentially effected on
all fingers and the average number of pseudo minutiae of all
fingers exceeds the threshold, the fingerprint image quality of a
finger which has the minimum average number of pseudo minutiae can
be judged to be best, and the pertinent finger is selected as the
best finger and its fingerprint is registered.
[0090] In the fingerprint checking device according to the
invention, the fingerprint image pickup unit takes a picture of a
fingerprint affixed on an image pickup face by a CCD camera or the
like, the image processor unit binarizes the fingerprint image and
thinning-processing it, and the minutiae detecting unit detects the
normal minutiae such as bifurcation points and ending points and
the pseudo minutiae such as pseudo bifurcation points and pseudo
ending points. The average pseudo minutia calculating unit counts
pseudo minutiae in the registering windows with the normal minutiae
at almost the center, adds up the pseudo minutiae in all
registering windows, and divides the total by the number of
registering windows to determine the average number of pseudo
minutiae in the registering windows.
[0091] In the fingerprint checking device according to the
invention, the judging unit, when the average number of pseudo
minutiae is equal to or below the threshold, judges that the
fingerprint image has a good image quality and registers the
pertinent fingerprint in the registering unit. And, the display
unit shows the average number of pseudo minutiae or information
related thereto and can indicate the fingerprint image quality in a
numerical value. And, the checking unit checks the registered
fingerprints with a fingerprint pictured by the fingerprint image
pickup unit.
[0092] In the fingerprint checking device according to the
invention, the judging unit, when the fingerprint image quality is
not good and the average number of pseudo minutiae exceeds the
threshold, shows the instructions for registering another finger on
the display unit. Accordingly, operation is effected to register
another finger and done on all fingers, and when the average number
of pseudo minutiae of all fingers exceed the threshold, registering
is rejected, or it is judged that the fingerprint image quality of
a finger which has the minimum average number of pseudo minutiae is
judged to be best, and the pertinent finger is selected as the best
finger and its fingerprint can be registered in the registering
unit.
[0093] A fingerprint registering method according to the invention
registers fingerprints of a prescribed number of at least two
supervisors in a fingerprint registering device by using a
fingerprint registering key, and a person who is to register a
fingerprint registers the affixed fingerprint in the fingerprint
registering device by means of the fingerprint registering key and
the registering permission according to the matching of the
fingerprint of at least one of the prescribed number of supervisors
who have registered their fingerprints.
[0094] The fingerprint registering method according to the
invention, when the fingerprint is registered in the fingerprint
registering device, also registers an attribute defining an
accessible range of persons who register fingerprints, and can
renew or delete the fingerprints or the attribute registered in the
fingerprint registering device by means of the fingerprint
registering key and the registration permission by matching of the
fingerprints of the supervisors who have registered their
fingerprints.
[0095] The fingerprint registering method according to the
invention, when the registered fingerprints of the supervisors are
required to be deleted or the attribute is required to be changed,
rejects the deletion requirement or the attribute change
requirement if the deletion or the attribute change results in that
the remaining number of supervisors who have registered
fingerprints becomes one or below the prescribed number.
[0096] A fingerprint checking entrance/exit control system
according to the invention comprises a fingerprint registering
device for registering a fingerprint and an attribute of a
fingerprint-registering person, a fingerprint checking unit for
checking the fingerprints registered in the fingerprint registering
device with the affixed fingerprint, a fingerprinting unit, and
fingerprint checking gates containing a control unit for
controlling to unlock according to the attribute and the result
obtained by checking the fingerprint affixed on the fingerprinting
unit and the fingerprint registered in the fingerprint registering
device, wherein the fingerprint registering device registers a
fingerprint by fingerprint registering operation by means of a
fingerprint registering key and the allowance of registering by
checking of the fingerprint of at least one supervisor.
[0097] The fingerprint checking entrance/exit control system
according to the invention provides the functions of the
fingerprint registering device on at least one of fingerprint
checking gates to share the structure of at least fingerprinting
unit.
[0098] A fingerprint checking method according to the invention for
binarizing a multivalued image obtained by picturing an affixed
fingerprint into a binarized image, dividing the binarized image
into a plurality of blocks, determining the direction of ridge
lines in respective blocks, effecting spatial filtering of the
multivalued image along the ridge line direction, and binarizing to
extract minutiae; wherein respective picture elements in the
respective blocks are detected by using a direction detecting mask
made of 3.times.3 picture elements to find which of a plurality of
directions they belong, the number of picture elements in each of
the plurality of directions is determined, the number of picture
elements in the respective directions is converted into a vector,
the maximum value in values obtained by adding respective direction
components on respective vectors is detected, and a direction
corresponding to the vector showing the maximum value is judged to
be the ridge line direction of the block. For example, directions
which mutually intersect at right angles are converted into vectors
which mutually counteract, and direction components are determined
on the respective vectors and added up, so that mutual cancellation
is made when the number of picture elements in the directions to
intersect at right angles is same. Therefore, detection is not made
in the direction of ridge lines opposite to the flow of ridge
lines.
[0099] After detecting the ridge line direction of the each block,
the average in the ridge line direction of a focused block and a
plurality of blocks around the focused block is determined to judge
as the ridge line direction of the focused block.
[0100] A fingerprint checking method according to the invention
registers registering fingerprint data derived from extraction of
minutiae from a fingerprint, checks the registered fingerprint data
with fingerprint data for checking an affixed fingerprint, and
authenticates personal identification depending on if they match,
wherein a conversion key number is produced by a previously defined
function from an entered key number and the content at a prescribed
byte in the registered fingerprint data, the conversion key number
is inserted for storing at a prescribed byte in the registered
fingerprint data, and a key number entered at the time of checking
the fingerprint is checked with a key number reconstructed from the
conversion key number inserted at the prescribed byte of the
registered fingerprint data, and the checking fingerprint data
obtained from the affixed fingerprint is checked with the
registered fingerprint data.
[0101] The key number entered and set in the key number setting
register and the content at the n-th byte of the registered
fingerprint data in the registered fingerprint data storage file
are added or subtracted to produce a conversion key number, the
conversion key number is inserted at the m-th byte of the
registered fingerprint data to store in a file, the content at the
n-th byte is subtracted or added with respect to the conversion key
number inserted at the m-th byte in the registered fingerprint data
at checking the fingerprint to reconstruct the key number, and the
reconstructed key number is checked with the entered key
number.
[0102] A fingerprint checking entrance/exit control system
according to the invention comprises a host device which has a file
for storing personal information containing entrance allowing
information according to an identification number, name and desired
room number and the registered fingerprint data in a corresponded
form and a gate which has a fingerprint checking unit for storing
the personal information and the registered fingerprint data
downloaded from the file and checking with an affixed fingerprint,
both connected through a local area network (LAN), wherein the
fingerprint checking unit of the gate is provided with a control
unit which renews the registered fingerprint data with a time stamp
added to the affixed fingerprint data when personal identification
is authenticated by checking the affixed fingerprint with the
registered fingerprint data, and the host device collects the
renewed registered fingerprint data with the time stamp added of
the gate, renews the registered fingerprint data and sends the
renewed registered fingerprint data to a gate which is in
compliance with the entrance allowance information.
[0103] The host device has a file which stores first and second
registered fingerprint data from a finger registering unit, and a
control processing unit, when the second registered fingerprint
data is renewed by the latest renewed registered fingerprint data
collected from the gate, renews the first registered fingerprint
data by the second registered fingerprint data, and transfers the
renewed second registered fingerprint data to a gate which is in
compliance with the entrance allowing information.
[0104] A fingerprint checking device according to the invention for
checking an affixed fingerprint on a fingerprinting unit with
registered fingerprint data in correspondence with normal
identification numbers stored in a file comprises a local ID file
which allocates a local identification number having the number of
digits smaller than the normal identification numbers and stores
the local identification number, and a control unit which reads
from the fingerprint dictionary file in the file the registered
fingerprint data corresponding to the local identification number
entered at the time of checking with the affixed fingerprint.
[0105] The local ID file stores the local identification number and
effective time information which indicates effective time of the
local identification number in a corresponded form.
[0106] The control unit allocates a local identification number
which does not overlap with another local identification number
registered in the local ID file, and corresponds the registered
fingerprint data which is corresponded with the normal
identification number with the local identification number.
[0107] A fingerprint registering method according to the invention
which binarizes a multivalued image signal obtained by picturing an
affixed fingerprint, thinning-processing image data resulting from
the binarizing process, extracts minutiae based on the
thinning-processed image data, deletes pseudo minutiae from the
minutiae, and when the remaining number of minutiae is equal to or
above a prescribed number, registers a fingerprint having minutiae
according to the binarized image data, wherein if the fingerprint
registering in the process for the first time fails, spatial
filtering is effected on the multivalued image data to continue in
the ridge line direction in the fingerprint registering process by
the process for the second time and following, the spatial filtered
multivalued image data is binarized and thinning-processed, the
minutiae are extracted from the thinning-processed image data, the
pseudo minutiae are deleted from the minutiae, and if the remaining
number of minutiae is equal to or more than a prescribed number,
the fingerprint having minutiae according to the binarized image
data is registered. In other words, the first fingerprint
registering process, when the fingerprint image is good, does not
need the spatial filtering to obtain the prescribed number or more
of normal minutiae. If the first registering process fails, the
fingerprint image is not good, so that the spatial filtering is
effected, and minutiae are extracted.
[0108] To delete the pseudo minutiae in the fingerprint registering
process, when the extracted minutiae are within a prescribed area,
they are judged as pseudo minutiae, and the pseudo minutiae are
deleted from a list of minutiae.
BRIEF DESCRIPTION OF THE DRAWINGS
[0109] FIG. 1 is an explanatory diagram of the embodiment of a
fingerprint checking device according to the present invention.
[0110] FIG. 2 is a flowchart of fingerprint registering process in
an embodiment according to the invention.
[0111] FIG. 3 is a flowchart of calculating the average number of
pseudo minutiae in a registering window in an embodiment according
to the invention.
[0112] FIG. 4 is a flowchart of selecting the best finger in an
embodiment according to the invention.
[0113] FIG. 5 is an explanatory diagram of an embodiment of a
fingerprint checking entrance/exit control system according to the
invention.
[0114] FIG. 6 is a menu explanatory diagram of an embodiment
according to the invention.
[0115] FIG. 7 is a flowchart of registering a fingerprint in an
embodiment according to the invention.
[0116] FIG. 8 is a flowchart of registering a new fingerprint in an
embodiment according to the invention.
[0117] FIG. 9 is a flowchart of renewing in an embodiment according
to the invention.
[0118] FIG. 10 is a flowchart of deleting in an embodiment
according to the invention.
[0119] FIG. 11 is an explanatory diagram of a file in an embodiment
according to the invention.
[0120] FIG. 12 is an explanatory diagram of judging the ridge line
direction of a fingerprint in an embodiment of a fingerprint
checking method according to the invention.
[0121] FIG. 13 is a flowchart of an embodiment according to the
invention.
[0122] FIG. 14 is a flowchart of an embodiment according to the
invention.
[0123] FIG. 15 is an explanatory diagram of a ridge line direction
pattern by an averaging process in an embodiment according to the
invention.
[0124] FIG. 16 is an explanatory diagram of a fingerprint checking
method according to the invention.
[0125] FIG. 17 is a flowchart of registering a fingerprint in an
embodiment according to the invention.
[0126] FIG. 18 is a flowchart of checking a fingerprint in an
embodiment according to the invention.
[0127] FIG. 19 is an explanatory diagram of an embodiment of a
fingerprint checking entrance/exit control system according to the
invention.
[0128] FIG. 20 is a flowchart of registering.
[0129] FIG. 21 is an explanatory diagram of a file.
[0130] FIG. 22 is a flowchart of checking a fingerprint.
[0131] FIG. 44 is an explanatory diagram of a fingerprint checking
entrance/exit control system.
[0132] FIG. 23 is an explanatory diagram of an embodiment of a
fingerprint checking device according to the invention.
[0133] FIG. 24 is an explanatory diagram of a fingerprint affixing
part, a ten-key and a display.
[0134] FIG. 25 is a flowchart of new registering.
[0135] FIG. 26 is a flowchart of requiring a local ID.
[0136] FIG. 27 is a flowchart of issuing a local ID having the
maximum digits or below.
[0137] FIG. 28 is a flowchart of checking a fingerprint by entering
a local ID.
[0138] FIG. 29 is a flowchart of an embodiment of a fingerprint
registering method according to the invention.
[0139] FIG. 30 is a flowchart of registering a fingerprint
according to prior art.
[0140] FIG. 31 is an explanatory diagram of normal minutiae and
pseudo minutiae.
[0141] FIG. 32 is an explanatory diagram of a fingerprint image and
a thinning-processed image.
[0142] FIG. 33 is an explanatory diagram of a fingerprint image and
a thinning-processed image.
[0143] FIG. 34 is an explanatory diagram of a system.
[0144] FIG. 35 is an explanatory diagram of a fingerprint checking
device.
[0145] FIG. 36 is an explanatory diagram of dividing a pictured
image into blocks.
[0146] FIG. 37 is an explanatory diagram of judging the direction
of picture elements.
[0147] FIG. 38 is a flowchart of prior art.
[0148] FIG. 39 is an explanatory diagram of detecting the direction
of ridge lines according to prior art.
[0149] FIG. 40 is an explanatory diagram of detecting the direction
of ridge lines according to prior art.
[0150] FIG. 41 is an explanatory diagram of a disadvantage of prior
art.
[0151] FIG. 42 is an explanatory diagram of a fingerprint checking
system.
[0152] FIG. 43 is an explanatory diagram of extracting a key
number-stored area according to prior art.
[0153] FIG. 45 is an explanatory diagram of a fingerprint checking
device.
[0154] FIG. 46 is an explanatory diagram of a binarized image of a
fingerprint.
[0155] FIG. 47 is an explanatory diagram of a thinning-processed
image of a fingerprint.
[0156] FIG. 48 is an explanatory diagram of a blurred
fingerprint.
[0157] FIG. 49 is an explanatory diagram of a binarized image of a
fingerprint.
[0158] FIG. 50 is an explanatory diagram of a multivalued image of
a fingerprint.
BEST MODE FOR CARRYING OUT THE INVENTION
Embodiment 1
[0159] FIG. 1 is an explanatory diagram of an embodiment of a
fingerprint checking device according to the present invention, in
which reference numeral 1 denotes a fingerprint image pickup unit,
2 an image processor unit, 3 a minutia detecting unit, 4 an average
pseudo minutia calculating unit, 5 a judging unit, 6 a registering
unit, 7 a display unit, 8 a checking unit, 9 a multivalued-image
capturing unit, 10 a binarized-image converting unit, and 11 a
thinning-processing unit. The fingerprint image pickup unit 1 can
apply various types of known configurations, and is generally
configured that a fingerprint affixing surface is illuminated by a
light source and the light reflected on the surface of a finger is
pictured by a CCD camera.
[0160] The image processing unit 2 digitizes a fingerprint image
from the fingerprint image pickup unit 1 into a multivalued level
by the multivalued-image capturing unit 9 and binarized by the
binarized-image converting unit 10. And, the binarized fingerprint
image is thinning-processed by the thinning-processing unit 11. For
example, as to a binarized image, the ridge lines of a fingerprint
are converted into lines of about one picture element as shown in
FIG. 31, FIG. 32 and FIG. 33(b) according to the judging processing
whether or not the adjacent picture elements with respect to the
focused picture element at the center are continuous by using a
3.times.3 picture element mask.
[0161] The minutia detecting unit 3 detects the thinning-processed
fingerprint image for bifurcation points where a prescribed number
of picture elements are continuous or ending points where there are
intervals of a prescribed number of picture elements as normal
minutiae, and detects bifurcation points and ending points under
other conditions as pseudo minutiae. In such a case, by using the
above-described 3.times.3 picture element mask for example, the
picture elements in the neighborhood of the focused picture
elements at the center can be judged whether or not they are
continuous or bifurcated, so that respective minutiae can be
detected.
[0162] With respect to a registering window with the normal minutia
by the minutia detecting unit 3 at almost the center, e.g., the
registering window shown in a rectangular form in the
thinning-processed image in FIG. 31(B), the average pseudo minutia
calculating unit 4 calculates pseudo minutiae, e.g., the pseudo
minutiae shown at P1 to P4 in FIG. 31(C), adds up the number of
pseudo minutiae of all registering windows, and dividing the total
by the number of registering windows to determine the average
number of pseudo minutiae of the registering windows.
[0163] The judging unit 5 judges that a fingerprint image is good
when the average number of pseudo minutiae is equal to or less than
a threshold, e.g., 5. For example, the number of pseudo minutiae in
the registering window shown in FIG. 31(C) is four, and when it is
assumed that the average number of pseudo minutiae is also four, it
is equal to or less than the threshold. In such a case, the
fingerprint image shown in FIG. 31(A) is judged to be of a good
image quality, and the pertinent fingerprint is registered in the
registering unit 6. In this case, coordinate information of the
registering windows containing the normal minutia and the binarized
image within the registering windows are registered. And, the
registering unit 6 can apply various types of storage devices such
as a semiconductor integrated circuit memory and a magnetic disk
drive.
[0164] Display unit 7 can be formed of a liquid crystal display
device, a CRT display device or the like, and shows the
above-described average number of pseudo minutiae, or indicates
that the fingerprint image has a poor image quality as the average
number of pseudo minutiae increases, so that the image quality can
be converted into a numerical value and displayed. Information on
the possibility of registering can also be indicated. When the
average number of pseudo minutiae exceeds a threshold in the
judging unit 5, it can be displayed to register another finger.
When the fingerprint of a best finger is registered, the best
finger can be displayed as the registered finger.
[0165] After registering a fingerprint in the registering unit 6,
the checking unit 8 checks the fingerprint pictured by the
fingerprint image pickup unit 1 with the registered fingerprint,
and when they match, it is judged as personal identification. And,
it can be applied to various types of security devices. The
functions of the above-described units can be achieved by the
individual configurations of the respective units or by a
calculating function of a processor or a memory.
[0166] FIG. 2 is a flowchart of registering a fingerprint in the
embodiment of the present invention, in which n denotes the number
of fingers to be registered. For example, a first finger is
indicated by 0, a second finger by 1, and a third finger by 2. And,
m[ ] is an address of a memory for storing the average number of
pseudo minutiae. For example, an address for storing the average
number of pseudo minutiae of a first finger is m[0], and an address
for storing the average number of pseudo minutiae of a second
finger is m[1].
[0167] First, when n=0 (A1), it is judged whether or not
fingerprinting has been made (A2), and if fingerprinting has been
made, the average number of pseudo minutiae in the registering
window is calculated by the average pseudo minutia calculating unit
4 (see FIG. 1) (A3). This average number of pseudo minutiae is
stored in an address m[0] of the memory. And, it is judged whether
or not the average number of pseudo minutia is equal to or less
than the threshold by the judging unit 5 (A5). When the average
number of pseudo minutia is equal to or less than the threshold, it
is judged that the fingerprint image is good, and the formal
registering is made (A7). Otherwise, temporary registering and
checking (A15) are performed before the formal registering, and if
they match, the formal registering can be made.
[0168] When the average number of pseudo minutiae exceeds the
threshold, the average number of pseudo minutiae is shown on the
display unit 7 (A8). In this case, the average number of pseudo
minutiae is displayed as a numerical value, or it can be displayed
in percentage indicating the image quality.
[0169] In accordance with what is displayed, it is judged whether
or not registering of another finger has been instructed (A9), and
if the instructions for registering another finger have been made,
the number of fingers n to be registered is stored as +1, and
processing goes to step (A2).
[0170] When repeated registering of all fingers has been completed,
there is no instructions for registering another finger remain, so
that it is judged whether or not there is any instructions for
registering the best finger (A10), and when there is such
instructions, selection of the best finger is performed (A11). And,
the fingerprint of the best finger selected by the best finger
selecting process is registered.
[0171] If there is not any instructions for registering the best
finger, it is judged whether or not there is forced registering
instructions (A12). In other words, when the average number of
pseudo minutiae of the fingerprints of all fingers exceeds the
threshold, a desired finger can be designated to make the forced
registering instructions, and the fingerprint of the designated
finger is registered. In this case, in the same way as prior art,
the temporary registering and the checking according to the affixed
fingerprint are performed, and when the temporarily registered
fingerprint and the affixed fingerprint match, processing goes to
the formal registering (A7), and when they do not match,
registering can be rejected. If there is not forced registering
instructions, it is judged whether or not there is a forced
termination instruction (A13), and if there is such an instruction,
processing is forced to be terminated, and if there is not,
processing goes to step (A9).
[0172] FIG. 3 is a flowchart of calculating the average number of
pseudo minutiae in the registering window in the embodiment of the
invention, in which an image signal from the fingerprint image
pickup unit 1 is converted into a multivalued digital signal and
captured by the multivalued image capturing unit 9 of the image
processor unit 2 (B1), it is converted into a binarized image by
the binarized-image converting unit 10 (B2), it is then masked and
thinning-processed by the thinning-processing unit 11 as described
above (B3), minutiae are extracted based on the thinning-processed
image by the minutia detecting unit 3 (B4), pseudo minutiae are
detected (B5), and normal minutiae for registering are extracted
(B6).
[0173] Then, in the average pseudo minutia calculating unit 4, the
number of pseudo minutiae within the registering window with the
normal minutiae at about the center is calculated (B7), a total of
pseudo minutiae in all registering windows is calculated (B8), and
the total is divided by the number of registering windows to obtain
the average number of pseudo minutiae (B9). Such calculation can be
performed at a high speed by combining the already known addition
with shifting.
[0174] FIG. 4 is a flowchart of selecting the best finger in the
embodiment of the invention, indicating the step (A11) of FIG. 2 in
detail. In the drawing, reference numeral n.sub.t denotes the
content of a counter which is used to select the best finger, and
m.sub.t the average number of pseudo minutiae. When the average
number of pseudo minutiae in the registering windows exceeds the
threshold and no instructions for registering another finger is
given, n.sub.t=0 (C1), then m.sub.t=m [0] (C2), and the average
number of pseudo minutiae m for the first finger is read to judge
whether or not m.sub.t>m [n.sub.t] (C3).
[0175] And, when m.sub.t>m [n.sub.t] m.sub.t.rarw.m [n.sub.t]
(C4), and it is judged whether or not n.sub.t=n (C5). Even when it
is not m.sub.t>m [n.sub.t], it is judged whether or not
n.sub.t=n. And, when n.sub.t=n, the finger which is indicated by
n.sub.t is determined as the best finger and registered (C7). When
n.sub.t.noteq.n, n.sub.t is counted up (C6), and processing goes to
step (C3). Thus, among all fingers, the finger having the minimum
average pseudo minutia which is not satisfactory as the fingerprint
image is temporarily selected as the best finger, and its
fingerprint is registered. In this case, the name and number of the
best finger are shown on the display unit 7 to notice a fingerprint
registering operator. Accordingly, the selected best finger may be
affixed to check a fingerprint.
Embodiment 2
[0176] FIG. 5 is an explanatory diagram of the embodiment of a
fingerprint checking entrance/exit control system according to the
present invention, in which reference numeral 21 denotes a
fingerprint registering device, 22 a fingerprint checking unit, 23
and 25 a modem, 24 a private branch exchange (PBX), 26-1 to 26-n a
fingerprint checking gate, 27 a control unit, 28 a clock, 29 a
fingerprinting unit, 30 a display unit, 31 a ten-key, 32 a relay,
33 an interface, 34-1 to 34-n an electric lock of the door to a
room where entrance and exit are made or of allowing to operate a
computer which stores significant data.
[0177] The fingerprint registering device 21 comprises an
unillustrated keyboard such as a ten-key, a key hole for a
fingerprint registering key, a fingerprinting part, a fingerprint
registering part and a display to indicate guidance. To start to
use the system, at least two supervisors (system administrator) are
selected, the fingerprint of each supervisor is registered by using
the fingerprint registering key, then a new fingerprint registering
person other than the supervisors inserts the fingerprint
registering key, and at least one supervisor affixes his or her
fingerprint on the fingerprinting part, and when the supervisor s
registered fingerprint matches with the affixed fingerprint and the
new fingerprint registering person affixes his or her fingerprint
on the fingerprinting part, data such as the identification number,
post, name, attribute and accessible door entered through the
keyboard and the fingerprint can be registered.
[0178] Specifically, the new fingerprint registering person can use
the fingerprint registering key upon being approved to register a
fingerprint by the supervisor, and by the fingerprint registering
approval by the direct fingerprint checking of the supervisor, the
fingerprint can be registered in the fingerprint registering device
21. Thus, since the fingerprint of the new fingerprint registering
person can be registered under the double guards of the fingerprint
registering key and the fingerprint checking of the supervisor,
security of the fingerprints registered in the fingerprint
registering device 21 can be improved.
[0179] The fingerprint checking unit 22 checks the registered
fingerprints with the affixed fingerprint, and can be composed of a
host computer. Since the fingerprint checking unit 22 and the
fingerprint registering device 21 have a common function in
processing the fingerprint, they can be achieved by the same
computer.
[0180] The fingerprint checking gates 26-1 to 26-n comprise the
modem 25, the control unit 27 configured of a microprocessor, the
clock 28 configured of a hard clock or soft clock, the
fingerprinting unit 29 configured of a light source and a CCD
camera, the display unit 30 such as a liquid crystal panel, the
ten-key 31 for entering an ID or the like, the relay 32 used for an
unillustrated power switch for the device, and the interface 33 for
releasing or locking the electric lock; and are provided for a room
where entrance and exit are made of a computer.
[0181] And, the fingerprint checking unit 22 and the fingerprint
checking gates 26-1 to 26-n are connected through the private
branch exchange 24 but may be connected by a dedicated line to form
the system. And, by providing a fingerprint checking unit which has
the same functions as the fingerprint checking unit 22 and a
storage unit which receives and stores online or off-line the
fingerprint data stored in the fingerprint registering device 21,
the registered fingerprints and the affixed fingerprint can be
checked separately at the fingerprint checking gates 26-1 to
26-n.
[0182] When a fingerprint is affixed on the fingerprinting unit 29,
a fingerprint image signal obtained by picturing the fingerprint
under the control of the control unit 27 is transferred to the
fingerprint checking unit 22 through the modem 25, the private
branch exchange 24 and the modem 23. The fingerprint checking unit
22 checks it with the registered fingerprints in the fingerprint
registering device 21, and sends back the checked result to the
fingerprint checking gate. Otherwise, at the fingerprint checking
gate which has the fingerprint checking unit, the affixed
fingerprint and the registered fingerprints can be checked without
transferring the fingerprint image signal.
[0183] If they match, the control unit 27 releases the electric
lock through the interface 33. When the accessible door is limited
at the time of registering a fingerprint, it is judged whether or
not the fingerprint matches at the fingerprint checking gate for
the accessible door, and if the fingerprint matches for the
accessible door, the entrance is allowed. And, if the fingerprint
affixed to the fingerprinting unit 29 does not match with any
registered fingerprint, it is shown on the display unit 30, and the
electric lock is not released. Therefore, if a person does not have
his or her fingerprint registered, the affixed fingerprint does not
match with the registered fingerprints and the entrance is not
allowed. And, when the fingerprint checking gate is provided for a
computer, the computer cannot be used when the fingerprints do not
match.
[0184] FIG. 6 is an explanatory diagram of a menu in the embodiment
according to the invention, showing one example of the operation
menu on the side of the fingerprint checking unit 22 to control the
entrance and exit (see FIG. 5). An initial menu 1-1 includes menus
such as fingerprint registration 2-1, registered data transmission
2-2, entrance record collection 2-3, printing/monitoring 2-4,
setting 2-5, unconditional unlocking 2-6, forced open monitoring
2-7, fingerprinting counter 2-8, backup 2-9, and termination 2-10.
Among them, the fingerprint registering 2-1, setting 2-5,
unconditional unlocking 2-6, fingerprinting counter 2-8, and
termination 2-10 can be operated by the supervisor (system manager)
only.
[0185] FIG. 7 is a flowchart of registering a fingerprint in the
embodiment according to the invention, showing the registering of
the fingerprint in the fingerprint registering device 21 shown in
FIG. 5. The fingerprint registration 2-1 of the menu of FIG. 6
shown on the fingerprint registering device 21 is designated. In
registering the fingerprint, the fingerprint registering key is
needed, and it is judged whether or not the fingerprint registering
key is turned on (A1). When the fingerprint registering key is not
inserted or it is inserted but not turned on, a message "Turn on
the key." is displayed, and the initial menu 1-1 resumes (A11).
[0186] When the fingerprint registering key is turned on, it is
judged whether or not the fingerprints of at least two supervisors
have been registered. Since the supervisors have the fingerprints
registered to give approval for registering a new fingerprint, if
there is only one supervisor at the time of operating the system
and any accident takes place, subsequent new registering, renewal
or deletion of a fingerprint cannot be made, so that at least two
supervisors are registered without reservation. Therefore, in step
(A2), it is judged whether or not two supervisors have been
registered, and if not, the fingerprints of two supervisors are
registered without reservation.
[0187] When a fingerprint is registered after registering the
fingerprints of two supervisors, the fingerprint registering key is
turned on, the fingerprints of the supervisors are affixed, it is
judged whether or not the supervisors could be identified by
checking the fingerprints (A5), and if the identification cannot be
made, a message "Not identified. Unless the supervisors are
identified, this menu cannot be used." is displayed (A6), and the
initial menu 1-1 resumes (A11).
[0188] When the supervisors are identified, processing goes to the
selection of processing (A7), and new 2-1-1 (A8), renewal 2-1-2
(A9), deletion 2-1-3 (A10), or initial menu 1-1 (A11) is selected.
And, after returning to initial menu 1-1, registered data
transmission 2-2 (A12) is automatically selected and transmitted to
the fingerprint checking gate.
[0189] FIG. 8 is a flowchart of registering a new fingerprint in
the embodiment according to the invention, showing that the
fingerprint registration 2-1 in the menu of FIG. 6 is selected, and
new 2-1-2 (A8) of FIG. 7 is selected. The fingerprints of two
supervisors have been registered, and the ID, post, name, use
condition, attribute and accessible door of a fingerprint
registering person are entered (B1). The attribute in this case
generally indicates an operator of the computer or a supervisor
managing the system. And, the accessible door means a computer
room, a room number or a door. As to the supervisor who has first
registered a fingerprint, the ID, post and name are entered, the
attribute is automatically determined as the supervisor, and the
accessible door can be selected.
[0190] Upon completing the above-described entry, a message "New
registering (Y/N)" is displayed (B2). And, a key indicating YES or
NO is operated, and it is judged which key is operated (B3). If the
NO key is operated and new registering is not effected, processing
goes to step (B1), and when the YES key is operated and new
registering is effected, the affixed fingerprint is captured (B4),
and the attribute entered in step (B1) is judged.
[0191] And, when the attribute is general, general new registering
(B6) is effected, when it is the operator, operator new registering
(B7) is effected, and when it is the supervisor, supervisor new
registering (B8) is effected. When the number of supervisors
registered is limited, the number of registered supervisors is
judged, and if it exceeds a prescribed number, registering of a
fingerprint with the attribute of the supervisor designated is
rejected.
[0192] Then, new registered data is shown (B9), it is checked by
the new fingerprint registering person, a message "Continue new
registering? (Y/N)" is shown (B10), it is judged which key has been
operated (B11), if a discontinue key is operated, menu of
fingerprint registering 2-1 resumes (B12). and if continue menu is
operated, step (B1) resumes.
[0193] FIG. 9 is a flowchart of renewing in the embodiment
according to the invention, showing the selection of renewal 2-1-2
of FIG. 7, and a message "Enter ID to be renewed." is shown (Cl).
And, when the ID to be renewed is entered, registered data
containing the post, name, use condition, attribute, accessible
door as well as the renewed ID is shown (C2).
[0194] And, selection is judged (C3), and when other is selected,
renewal item is entered (C5), and processing goes to step (C1).
And, when termination is selected, a message "Renew (Y/N)" is shown
(C4), it is judged which key has been operated for entry (C5), if a
non-renewal key is operated, processing goes to step (C15), and if
a renewal key is operated, the affixed fingerprint is captured
(C9), and the attribute is judged (C10).
[0195] When the attribute is general, operator or supervisor, the
general renewing (C11), operator renewing (C12) or supervisor
renewing (C13) is performed, renewed data is shown (C14) to allow
the check of the renewed content, and a message "Continue renewing?
(Y/N)" is shown (C15), it is judged which key has been operated
(C16), and when a non-renewal key is operated, processing returns
to the menu of fingerprint registering 2-1 (C17), and when a
renewing key is operated, processing returns to step (C1). In the
supervisor renewing (C13), when renewal of the attribute results in
that the number of remaining registered supervisors does not meet
the prescribed number of at least two, the pertinent attribute
renewal request is rejected.
[0196] FIG. 10 is a flowchart of deleting in the embodiment
according to the invention, showing the detection of deletion 2-1-3
in FIG. 7, and according to a message "Enter ID to be deleted."
(D1), the ID to be deleted is entered. Data of the pertinent ID,
post, name, use condition, attribute and accessible door is shown
(D2). And, a message "Delete (Y/N)" is shown (D3), it is judged
which key has been operated (D4), if a non-deletion key has been
operated, processing goes to step (D10), and if a deletion key has
been operated, the attribute is judged (D5), and according to the
attribute, general deleting (D6), operator deleting (D7) or
supervisor deleting (D8) is performed, and deletion data is shown
for confirmation (D9).
[0197] In the supervisor deleting (D8), when the deletion remains
two or more supervisors, deletion is performed, but if it is one,
deletion is rejected. It can be determined that the number of
remained supervisors is a prescribed number of at least two, and if
the remaining supervisors may be less than the prescribed number,
the pertinent supervisor deletion request can be rejected.
[0198] Then, a message "Continue deleting? (Y/N)" is displayed
(D10), and it is judged which key has been operated in response
(D11). When a non-continuing key has been operated, processing
returns to the menu of fingerprint registering 2-1 (D12), and when
the continuing key has been operated, processing returns to step
(D1).
[0199] As described above, according to the fingerprint registering
key and the supervisor fingerprint checking, new registering,
renewal or deletion of the fingerprint can be made, security of the
registered fingerprints under the double guards can be improved,
and safety of entrance and exit according to the registered
fingerprints can be secured.
[0200] FIG. 11 is an explanatory diagram of files in the embodiment
according to the invention, containing a registering number of
people management file 41, a personal information file 42 and a
fingerprint dictionary file 43. The registering number of people
management file 41 manages the number of people having fingerprints
registered according to the attributes of supervisor, operator and
general. And, the personal information file 42 registers the
contents of respective items of ID, name, attribute, and accessible
door entered at the time of registering fingerprints. And, the
fingerprint dictionary file 43 contains a fingerprint dictionary in
correspondence with the ID, and the fingerprint dictionary
registers fingerprints by known means using minutiae of
fingerprints to form a checking dictionary.
[0201] Therefore, in step (A2) of FIG. 7, it is easy to judge
whether or not the registered number of supervisors has exceeded
two by referring to the registering number of people management
file 41. And, in the case of the new registering shown in FIG. 8,
the number of people corresponding to the attributes of the
registered number of people file 21 is added, and the ID, name,
attribute and accessible door for new registering is added to the
personal information file 42, and the ID and fingerprint for new
registering are added to the fingerprint dictionary file 43.
[0202] In the case of renewal shown in FIG. 9, to renew the
attribute, the number of people with the pertinent attributes given
in the registering number of people managing file 41 is renewed. In
such a case, the number of supervisors is checked, and when the
registered number of supervisors renewed keeps the prescribed
number of two or more, the renewal of the attributes of the
supervisors is approved, and when the registered number of
supervisors becomes below the prescribed number by renewing from
the attributes of the supervisors to other attributes, it can be
controlled to reject the renewal. And, the personal information
file 42, when the renewal is approved, is renewed according to the
contents of the renewal registration. The fingerprint dictionary
file 43 has the pertinent ID renewed.
[0203] In the case of deletion shown in FIG. 10, the number of
people with the pertinent attribute in the registering number of
people managing file 41 is subtracted. In such a case, the number
of supervisors is checked, and when the number of supervisors after
deleting is the prescribed number of at least two, the deletion is
approved, and when it is below the prescribed number of at least
two, it can be controlled that deletion is not approved. And, the
personal information file 42 deletes the pertinent data when the
deletion is approved. And, the fingerprint dictionary file 43 has
the pertinent ID deleted.
[0204] At the time of registering a fingerprint and checking a
fingerprint in the entrance and exit control, by referring to the
above-described file, security in registering, renewing or deleting
a fingerprint and security of entrance and exit control can be
improved.
Embodiment 3
[0205] FIG. 12 is an explanatory diagram of judging the ridge line
directions of a fingerprint in the embodiment of a fingerprint
checking method according to the invention. For example, as shown
in FIG. 37, the directions of respective picture elements in the
block are detected to belong to which of the directions 1 to 8
shown at the lower right in the drawing by using a direction
detecting mask formed of 3.times.3 picture elements. And, the
picture element is added for every directions (inclinations) 1 to
8. The contents of a totaling register showing the number of
picture elements added to correspond with the directions 1 to 8 at
that time are indicated as vectors V1 to V8. In other words, the
number of picture elements added in the direction 1 of FIG. 37 is
vector * V1, the number of picture elements added in the direction
2 is vector * V2, the number of picture elements added in the
direction 3 is vector * V3, and as described above, the directions
which intersects at right angles like the directions 1 and 5 are
determined as mutually offsetting directional vectors like vector *
V1 and vector * 5.
[0206] And, with respect to the vector * V1, a component in the
direction of * V1 of vectors * V2 to * V8 is determined and added.
For example, the component in the direction of * V1 of vector * V2
is V2 indicated by a dotted arrow, and the component in the
direction of * V1 of vector * V8 is V8 indicated by a dotted arrow.
And, vectors * V3, * V7 intersect with vector * V1 at right angles,
so that the component in the direction of * V1 is zero. And, since
vector * V5 is in the direction of 180 degrees with respect to
vector * V1, the component in the direction of * V1 is -V5.
Besides, the component in the direction of * V1 of vector * V1 is
-V4 as indicated by a dotted arrow, the component in the direction
* V1 of vector * V6 is -V6 as indicated by a dotted arrow.
Therefore, when the component in the direction of * V1 is added,
R1=V1+V2+V8-V4-V6.
[0207] Similarly, as to the directions of vectors * V2 to * V8, R2
to R8 are determined with the components in the respective
directions added, and the direction which has the maximum value
among the added results R1 to R8 is determined as the direction of
ridge lines in the block. For example, when the number of picture
elements of vectors * V1, * V3 is many, the number of picture
elements of vector * V2 is smaller than that, and the number of
picture elements of other vectors * V4 to * V8 is much smaller than
that, the direction of vector * V1 or * V3 is determined as the
direction of ridge lines in prior art. But, since the added result
of the component in the direction * V2 is the maximum value, the
direction of * V2 between vectors * V1 and * V3 is determined as
the direction of ridge lines.
[0208] FIG. 13 and FIG. 14 show a flowchart in the embodiment
according to the invention. In steps (A1) to (A8), in the same way
as shown in steps (B1) to (B8) of prior art shown in FIG. 38, block
number m and picture element number n in the block are determined
to be an initial value 1, the content of the totaling register
corresponding to a direction is determined to be an initial value
0, and the direction of picture element P.sub.m. n (m=1.about.1024,
n=1.about.256) is detected by using a direction detecting mask made
of 3.times.3 picture elements. And, as to the binarized image of a
finger, a histogram of picture elements in the block is produced in
respective directions.
[0209] Then, it is determined that R=V1. Specifically,
direction-oriented totaling register content V1 is determined to be
register R. And, it is determined that j=i+1 (A10), and j is
compensated (A11). When i=1, this j compensation is indicated as
j=i+1=2, indicating vector * V2 at 45 degrees with respect to
vector * V1, but when i=8, it is j=8+1=9, so that it is judged
whether or not j exceeds 8, and if j exceeds 8, processing to
satisfy j=j-8 is indicated.
[0210] And, totaling register content Vj in direction j is
multiplied by 1/2.sup.1/2 to determine a component in direction j,
and it is added to the register R (A12). For example, as to the V1
direction component of vector * V2, since * V2 is in a direction of
45 degrees with respect to * V1, V2 indicated by a dotted arrow is
obtained by multiplying * V2 by 1/2.sup.1/2. Namely, step (A12)
shows to add this V2 to V1.
[0211] Then, it is determined that j=i+7 (A13), and j is
compensated (A14). In this case, when i=1, then j=8. But, when i=2,
then j=2+7=9. Therefore, when j>8, compensation for j=j-8 is
effected. And, in the same way as step (A12), addition of
R=R+(Vj/2.sup.1/2) is effected to determine V1 direction component
of Vj (A15). In this case, it is shown that when i=1, addition is
effected to determine a V1 direction component V8 of V8 in FIG.
1.
[0212] When it is determined that j=j+3 (A16), the same j
compensation as in steps (A11), (A14) is effected (A17). In this
case, when i=1, then j=4, and since the * V1 direction component V4
of * V4 is in the direction opposite from * V1, it is determined to
be -V14-V4, and (V1-V4) is calculated. Step (A18) shows this
processing.
[0213] It is then determined that j=j+5 (A19), and the j
compensation is effected in the same way as in steps (A11), (A14)
and (A17) (A20), and the same calculation as in step (A18) is
effected (A21). Then, when j=j+4 (A22), the same j compensation as
above is effected (A23), and calculation of R=R-Vj is effected
(A24). In this case, when i=1, then j=5, and it means vector * V5
in FIG. 12. Since * V5 is in the direction 180 degrees opposite
from * V1, the * V1 direction component of * V5 becomes -V5, so
that processing of V1-V5 is performed.
[0214] And, it is judged whether or not Sm<R (A25). In other
words, the content Sm of the maximum valued register for each block
is compared with the content R of the totaling register and when
Sm<R, the content Sm of the maximum valued register is converted
into the content R of the totaling register (A26), and the content
Dm of the direction register is determined as the direction i at
the time (A27).
[0215] And, when it is not Sm<R and next to step (A27), it is
judged whether or not i=8 (A28). In other words, it is judged
whether or not processing has been completed in the directions 1 to
8, and if not, it is determined that i=i+1 (A29), and processing
goes to step (A9). And, if it has been completed, it is judged
whether or not m=1024 (A3). Namely, it is judged whether or not
processing on 1 to 1024 blocks has been completed, and if not, then
m=m+1 (A31), and processing goes to step (A2). If it has completed,
the content Sm of the maximum valued register corresponding to the
block is fixed as the maximum value. And, the direction
corresponding to the maximum value is stored in the direction
register Dm.
[0216] The pattern in the direction of ridge lines corresponding to
the block thus obtained is along the flow of the ridge lines, and
by effecting the spatial filtering based on it, occurrence of a
bridge between the ridge lines as in prior art can be
prevented.
[0217] As to the pattern in the direction of ridge lines
corresponding to the block, to further smooth the flow of ridge
lines, a 3.times.3 block structured mask is used to determine the
average of the focused blocks at the center and the peripheral
blocks in the direction of ridge lines, so that it can be
determined as the direction of ridge lines of the focused
blocks.
[0218] FIG. 15 is an explanatory diagram of a pattern in the
direction of ridge lines by averaging processing in the embodiment
of the invention. As described above, a 3.times.3 block configured
mask is used to determine the average of ridge line directions in
the focus blocks. It is apparent by comparing the pattern of FIG.
15 with the pattern shown in FIG. 39(C) or FIG. 41(A) that the flow
of ridge lines is smoothed by the averaging process in the
embodiment according to the invention, it is used to effect the
spatial filtering, and binarizing is performed, so that accurate
minutiae of a fingerprint can be extracted easily.
[0219] The above-described embodiment is a case that the picture
elements in each block of the binarized image are in eight
directions, but not limited to such directions and may be four or
six directions for detection. And, the added value of picture
elements in each direction is expressed in vector, addition is
effected to determine the direction component for each vector, and
the direction where such added value becomes maximum can be
determined as the direction of ridge lines of the pertinent
block.
Embodiment 4
[0220] FIG. 16 is an explanatory diagram of the embodiment of a
fingerprint checking method according to the present invention, in
which a conversion key number s is produced by a previously defined
function by a computing unit 53 such as an adder, subtracter,
multiplier or scientific calculator from a content d at the n-th
byte of fingerprint data in a registered fingerprint data storage
file 51 and a key number k set for a key number setting register
52, and it is inserted at the m-th byte of the fingerprint data.
And, FIG. 16 also shows a state with a data destruction checking
code added. In this case, n, m and k are kept confidential, and n
and m can be any arbitrary value and determined in advance.
[0221] For example, when it is assumed that the content d at the
n-th byte of the registered fingerprint data is 18.sub.(h) in
hexadecimal notation, the key number k which is entered through a
keyboard or ten-key and set for the key number setting register 52
is 7(h), and the computing unit 53 is an adder, then
s=d+k=18.sub.(h)+7.sub.(h)=1F.sub.(h), and the conversion key
number s is inserted at the m-th byte of the registered fingerprint
data.
[0222] When the key number k=7.sub.(h) is entered to check a
fingerprint, the fingerprint checking device reads the content
d=18.sub.(h) at the n-th byte of the registered fingerprint data
and the conversion key number s=F(h) at the m-th byte, the
computing unit 3 is operated as a subtracter, and the key number k
can be reconstructed by computing
k=s-d=1F.sub.(h)-18.sub.(h)=7.sub.(h), so that the reconstructed
key number k is checked with the entered key number, and when they
match, checking of the affixed fingerprint and the registered
fingerprints are started. But, if the key number does not match, it
is judged not to be a normal fingerprint check, and the subsequent
processing is rejected.
[0223] The computing unit 53 functions as an adder at the time of
producing a conversion key number and as a subtracter at the time
of reconstructing the conversion key number, but it can be
functioned as a subtracter at the time of producing the conversion
key number and as an adder at the time of reconstructing the
conversion key number. It is also possible to perform various
functional calculations such as the above-described addition or
deduction by multiplying the entered key number k or the content d
at the n-th byte by a constant, and a method of effecting various
functional calculations can be applied in accordance with the
system. Accordingly, even when the conversion key number s is read,
the reconstruction of the key number k can be disabled.
[0224] As described above, since the conversion key number is
stored together with the registered fingerprint data, the
registered fingerprint data has a random property even when the
fingerprint registering is repeated with the entered key number
constant, possibility is low that the content d at the n-th byte of
the registered fingerprint data becomes same, and the conversion
key number varies every time a fingerprint is registered.
Therefore, as described in connection with FIG. 5, even when the
registered fingerprint data is checked after entering the same key
number to register a fingerprint, it is impossible to find a
position where the key number is inserted upon matching. And, if
the registered fingerprint data is altered, the conversion key
number cannot be reconstructed, so that misuse can be
prevented.
[0225] FIG. 17 is a flowchart of registering a fingerprint in the
embodiment according to the invention, in which it is judged
whether or not the key number k has been set for the key number
setting register 52 (A1), and if it has been set, fingerprinting is
instructed (A5), but if not, the entry of the key number is
instructed (A2).
[0226] After instructing the entry of the key number, it is judged
whether or not the key number has been entered (A3), if the key
number has been entered, the key number k is stored in the key
number setting register 2 (A4), and processing goes to step (A5).
And, it is judged whether or not the fingerprinting has been
detected (A6), and if the fingerprinting is detected, the
registered fingerprint data is produced in view of the extracted
minutiae (A7).
[0227] And, the content d at the n-th byte of the registered
fingerprint data is stored in the register (A8), the conversion key
number s is produced by calculating, e.g., s=d+k by the computing
unit 53 (A9), the conversion key number s is inserted at the m-th
byte of the registered fingerprint data (A10), and the registered
fingerprint data is stored in the file (A11).
[0228] FIG. 18 is a flowchart of checking a fingerprint in the
embodiment according to the invention, in which it is judged
whether or not the key number has been set (B1), if it has not been
set, entry of the key number is instructed (B2), it is judged
whether or not the entry of the key number has completed (B3), and
when the key number is entered in accordance with the instructions
for entering the key number, the key number k is stored in the
register (B4).
[0229] When the key number has been set or it has been entered, the
content d at the n-th byte of the registered fingerprint data is
read and stored in the register (B5), then the conversion key
number s in the content at the m-th byte of the registered
fingerprint data is read and stored in the register (B6), and the
conversion key number s is reconstructed by the computing unit 53.
For example, the key number k is reconstructed as k=s-d, and the
reconstructed key number k is checked with the entered key number
(B7).
[0230] If they do not match, check rejection processing is effected
(B12). For example, a message "Key numbers do not match." is
displayed, and the subsequent processing is canceled. And, when
they match, fingerprinting is instructed (B8), and it is judged
whether or not fingerprinting is detected (B9), if fingerprinting
is detected, a fingerprint is checked according to some known
method (B10), and the checked result is noticed (B11). For example,
when the entered fingerprint matches, an unlocking signal is sent
to allow the entrance.
Embodiment 5
[0231] FIG. 19 is an explanatory diagram in the embodiment of a
fingerprint checking entrance/exit control system according to the
invention, in which reference numeral 61 denotes a host device,
62-1 to 62-n a gate, 63 a line for a local area network (LAN) or
the like, 64 a fingerprint registering unit, 65 a control
processing unit, 66 a file, 67 and 78 an interface (IF), 71 a
control unit, 72 a file, 73 a fingerprinting unit, 74 a display
unit, 75 a ten-key, 76 a clock unit, and 77 an electric lock.
[0232] The host device 61 is connected with a plurality of gates
61-1 to 61-n through the line 63 to form the fingerprint checking
entrance/exit system, and a fingerprint registering device can be
connected to the line as shown in FIG. 44. And, at the time of
registering a fingerprint by the fingerprint registering unit 64 of
the host device 61, personal information of name, post,
identification number (ID) and entrance allowing information
according to desired room number are entered, and a fingerprint is
affixed. The personal information entered at the time of
registering the fingerprint is stored in the personal information
file of the file 66, the fingerprint data formed by extracting
minutiae of the affixed fingerprint is stored in a fingerprint
dictionary file, and the identification number (ID) corresponding
to the room number according to the entrance allowing information
is stored in a possessed ID file.
[0233] The control processing unit 65 controls the fingerprint
registering in the fingerprint registering unit 64, the production
of the personal information file, fingerprint dictionary file and
possessed ID file in the file 66, the collection of renewal
registered fingerprint data at the gates 62-1 to 62-n, and the
transmission of the renewal registered fingerprint data to the
gates with reference to the possessed ID file. For example, the
above-described functions can be achieved by a program-controlled
processor.
[0234] The gates 62-1 to 62-n indicate the control of an electric
lock 77 for allowing the opening or closing of a door, but can also
be applied when the use of a specified device such as a computer is
allowed by checking a fingerprint by providing the electric lock
which allows to use the device. And, the file 72 is for storing
personal information and registered fingerprint data downloaded
from the file 66 of the host device 61, and the control unit 71
configures a fingerprint checking unit for checking the registered
fingerprint data stored in the file 72 with a fingerprint affixed
on the fingerprinting unit 73, controls to release the electric
lock 77 when personal identification is authenticated by checking
the fingerprint, adds a time stamp according to time indicated by
the clock unit 76, controls to renew the registered fingerprint
data stored in the file 72 by the affixed fingerprint data, and
upon the request from the host device 61, controls to send renewal
registered fingerprint data. For example, such functions can be
achieved by a program-controlled processor.
[0235] FIG. 20 is a flowchart of registering, in which personal
information such as name, identification number (ID), post and
desired room number is entered into the fingerprint registering
unit 64 of the host device 61 or the fingerprint registering device
not shown in FIG. 19 (A2), and the first fingerprinting is effected
(A2). Fingerprint data according to the first fingerprinting is
temporarily registered (A3). Then, the second fingerprinting is
effected (A4). And, the fingerprint data according to the first
fingerprinting is checked with fingerprint data according to the
second fingerprinting to judge whether or not they match (A5). In
other words, they are mutually checked as registered fingerprint
data and affixed fingerprint data, and when the personal
identification is authenticated, it is judged as acceptance, and if
it is judged as rejection, the registering operation is determined
as failure (A7). In this case, the fingerprint registering
operation is effected from beginning.
[0236] And, if matched in the fingerprint checking, the control
processing unit 65 controls to produce the file 66 (A6). In other
words, the personal information file, the fingerprint dictionary
file containing the first registered fingerprint data according to
the first fingerprinting and the second registered fingerprint data
according to the second fingerprinting, and the possessed ID file
prepared according to entrance allowing information are prepared.
And, the fingerprint dictionary file is transferred to the setting
gate according to the possessed IF file (A8). In this case,
transmission is made with the identification number (ID) of
personal information corresponding to the registered fingerprint
data added. Otherwise, it can be controlled to transmit upon
request for the registered fingerprint data based on the
identification number (ID) from the gates 62-1 to 62-n.
[0237] FIG. 21 is an explanatory diagram of a file, showing an
example of a personal information file 81, a fingerprint dictionary
file 82 and a possessed ID file 83. And, the personal information
file 81 shows a case of ID=ida, name=OGABW, post=GPRJ and entering
room numbers=G1.about.Gn, and a supervisor enabling to use the host
device or attribute such as general personnel who are not allowed
to use can be stored. And, information such as operation records of
personal information can also be stored.
[0238] And, the fingerprint dictionary file 82 shows a case of
ID=ida, registered fingerprint data=RD1, RD2, and time stamps=TS1,
TS2. In other words, first registered fingerprint data RD1
according to the first fingerprinting at registering the
fingerprint and second registered fingerprint data RD2 according to
the second fingerprinting are stored. And, the possessed ID file 83
has fingerprint-registered IDs stored in correspondence with the
gates G1 to Gn. For example, the gate G1 shows a case that IDs such
as ida, idb and ide are set, and ID=ida is set for all gates G1 to
Gn.
[0239] FIG. 22 is a flowchart of checking a fingerprint, in which
first an ID is entered through the ten-key 75 at the gate for a
room to be entered (B1), and a fingerprint is affixed to the
fingerprinting unit 73 (B2). In this case, a message according to
the operation order can be shown on the display unit 74. And, the
control unit 71 judges whether or not registered fingerprint data
corresponding to the entered ID is in the file 72 (B3), and if not,
transfers the fingerprint dictionary file (B4). In other words, the
address of the host device 61 is added, and a registered
fingerprint data requiring signal containing the ID and the gate
address is sent to the line 63 through the interface 78.
[0240] The host device 61 receives the registered fingerprint data
requiring signal through the interface 67, reads the registered
fingerprint data corresponding to the ID from the file 66, and
sends to the line 63 through the interface 67 with the gate address
added. The gate requiring the registered fingerprint data receives
the registered fingerprint data through the interface 18 and stores
in the file 12. Thus, download of the registered fingerprint data
is completed.
[0241] And, the affixed fingerprint is checked with the first
registered fingerprint data (B5), it is judged whether or not
personal identification has been authenticated (B6), and if not
authenticated, the affixed fingerprint is checked with the second
registered fingerprint data (B8), it is judged whether or not
personal identification has been authenticated (B9), and if not
authenticated, fingerprint checking is terminated because personal
identification can not be authenticated even by the second
fingerprint checking, and, it is shown on the display unit 74 that
checking has failed.
[0242] When personal identification is authenticated in step (B6),
the first registered fingerprint data is renewed by the affixed
fingerprint data (B7). And, when personal identification is
authenticated in step (B9), the second registered fingerprint data
is renewed by the affixed fingerprint data (B10). And, a time stamp
according to the time of the clock unit 76 is added to the renewed
fingerprint data (B11). In this case, date can also be contained in
addition to time.
[0243] And, according to periodical collection of renewal
fingerprint data from the host device 61, the control unit 71
refers to the time stamp added to the renewal registered
fingerprint data of the file 72 or uses the flag already sent to
the host device 61, identifies renewal registered fingerprint data
not sent to the host device 61, and sends the renewal registered
fingerprint data, the time stamp and the ID to the host device 61.
The host device 61 renews the fingerprint dictionary file according
to the ID of the collected renewal registered fingerprint data. In
this case, the time stamp is referred to, and even when the renewal
registered fingerprint data of a time stamp older than the time
stamp already renewed is collected, renewal is not effected
according to it.
[0244] As to the fingerprint dictionary file 82 shown in FIG. 21,
the time stamp added to the collected renewal registered
fingerprint data is referred to, and when the time stamp is latest,
the first registered fingerprint data RD1 is renewed according to
the second registered fingerprint data RD2, and the second
registered fingerprint data RD2 is renewed according to the
collected renewal recorded fingerprint data. Therefore, the
fingerprint dictionary file 82 in the file 66 of the host device 61
stores the latest renewal registered fingerprint data and the
previous renewal registered fingerprint data.
[0245] The host device 61, upon completion of renewing the
fingerprint dictionary file 82, refers to the possessed ID file 83,
and sends the renewed registered fingerprint data to the gate
having the ID having the renewed registered fingerprint data (B12).
Thus, without increasing the data transmission volume through the
line 3 between the host device 61 and the respective gates 61-1 to
62-n, the registered fingerprint data stored in the fingerprint
dictionary file of the file 33 according to the host device 61 can
be determined to be identical with the registered fingerprint data
which corresponds to the gate with the entering room
determined.
[0246] In steps (B3) to (B11), in the same way of renewing the
fingerprint dictionary file 82 of the file 66 in the host device
61, it can be controlled so that the second registered fingerprint
data is renewed by the affixed fingerprint data, and the first
registered fingerprint data is renewed by the second registering
fingerprint data. And, as to the system using one registered
fingerprint data corresponding to ID, a study function of renewing
the registered fingerprint data by the affixed fingerprint data can
be applied when personal identification is authenticated. And, a
data transmission format between the host device 61 and the gates
62-1 to 62-n can be selected in accordance with the use of a public
circuit or LAN for the line 63.
Embodiment 6
[0247] FIG. 23 is an explanatory diagram in the embodiment of a
fingerprint checking device according to the invention, in which
reference numeral 91 denotes a fingerprint checking device, 92 a
control unit, 93 a fingerprinting unit, 94 a display unit, 95 a
ten-key, 96 a clock unit, 97 a control output unit, 98 a file, 99 a
fingerprint dictionary file, 100 a personal information file, 101 a
local ID file, 102 an interface (IF), and 103 a line such as a
local area network (LAN) or public circuit.
[0248] Multiple fingerprint checking devices 91 are connected
through the line 103, and an unillustrated host device is also
connected to form the entrance/exit control system. In such a case,
when personal identification is authenticated by checking a
fingerprint, an unlocking signal is given to an unillustrated
electric lock from the control output unit 7, and the lock is
released to allow entrance. And, the host device has personal
information such as name, post, desired room number, identification
number (hereinafter called "ID") and registered fingerprint data in
correspondence with the ID, and the personal information and the
registered fingerprint data can be downloaded into the file 98 of
the fingerprint checking device 91 through the line 103. And, such
control means is already known.
[0249] Into the fingerprint dictionary file 99 of the file 98, the
above-described registered fingerprint data is stored, and personal
information is stored in the personal information file 100. The
normal ID in the personal information and the registered
fingerprint data in the fingerprint dictionary file 99 are mutually
linked and stored, and the normal ID is entered from the ten-key
95, so that the control unit 92 can read the registered fingerprint
data corresponding to the entered normal ID from the fingerprint
dictionary file 99 and check with the affixed fingerprint. And, the
local ID file 101 is for storing a local ID having the number of
digits smaller than the ID used for registering a fingerprint,
namely, the normal ID. This local ID is allocated so as not to
overlap.
[0250] FIG. 24 is an explanatory diagram of the fingerprinting
unit, ten-key and display unit, in which the fingerprinting unit 93
indicates a finger positioning stand, and an unillustrated CCD
camera and a lighting source are positioned below it. And, the
display unit 94 is made of a liquid crystal display panel, and a
message "Enter ID." is displayed as shown in the drawing. It is
also possible to display the position of a finger on the
fingerprinting unit 93, so that a finger can be guided to a proper
position. And, the ten-key 95 has function keys other than those
illustrated.
[0251] FIG. 25 is a flowchart of new registering, showing that when
there is provided the fingerprint registering unit of an
unillustrated host device, a device dedicated for fingerprint
registering, or a fingerprinting unit provided on the fingerprint
checking device, the fingerprint registering and the local ID
registering are effected by the fingerprint registering unit.
First, an ID is entered (A1), it is judged whether or not the ID
has been registered (A2), if it has been registered, it is
displayed that it cannot be used because it has been registered and
overlaps (A3), and processing returns to the first step.
[0252] If the entered ID has not been registered, personal
information such as post, name and accessible door number is
entered (A4), and personal information containing the ID is
registered (A5). Then, it is judged whether or not it is local ID
setting (A6), and if not, processing goes to fingerprint
registering (A12). If it is local ID setting, a local ID is entered
(A7), accessible door number is entered (A8), it is judged whether
or not it is a registered local ID (A9), and if it is a registered
local ID, it is displayed that it becomes an overlapped local ID
(A10), and processing goes to step (A6) to allow the entry of
another local ID.
[0253] If it is not a registered local ID, the entered local ID is
registered (A11), and processing goes to fingerprint registering
(A12). This fingerprint registering can apply some already known
means, for example, an image obtained by picturing an affixed
fingerprint is binarized, minutiae such as bifurcation points are
extracted to prepare fingerprint data, such data is determined to
be registered fingerprint data and stored in a file in connection
with the ID. And, it is judged whether or not new registering is
continued (A13), and if the new registering is continued,
processing goes to step (A1), and if it is not continued,
processing is terminated.
[0254] This local ID, if "0" is not allocated, can be a single
digit when nine or less people want to enter a room. In such a
case, the same local ID can be determined for a desired room. For
example, when the normal ID is "32145" and the local ID "3" is
determined for a plurality of rooms, the entry of the one-digit
local ID and fingerprinting are sufficient, so that operability is
improved remarkably.
[0255] When "0" and "00" are not allocated for the local ID, a
2-digit local ID can be allocated to 99 or smaller people who want
to enter a room. And, as described above, when the maximum number
of registered fingerprint data which can be stored in a single
fingerprint checking device is 480, three digits are sufficient to
allocate a local ID to them. Therefore, when a particular normal ID
is allocated to at least 10000 people, the normal ID has at least
five digits, but by allocating the local ID, the number of digits
can be sufficient to be smaller than the normal ID, so that the
entry of ID is easy for fingerprint checking.
[0256] FIG. 26 is a flowchart of requiring a local ID, showing that
after registering an ID and a fingerprint, a local ID is set in the
fingerprint checking device or a fingerprint registering device,
and the effective period of the local ID is determined. In other
words, the local ID requirement is entered (B1), and an n-digit
normal ID is entered (B2). And, a fingerprint is affixed (B3), and
it is checked to authenticate personal identification (B4). If the
checked result is NG, it means that the entry of the normal ID is
wrong or the subject person is not the right one for the normal ID,
and processing goes to step (B2).
[0257] If the checked result is OK, an n digit local ID with an
effective time set is issued. In this case, it means that N<n,
and the fingerprint checking side allocates the local ID while
avoiding overlapping. And, the effective time also shows to
previously determine by the fingerprint checking device, and
various types of effective time setting means of a method which
keeps all issued local IDs effective until the same time or a
method which issues a local ID and keeps it effective for a
prescribed period can be adopted according to the properties of the
system.
[0258] FIG. 27 shows a flowchart of issuing a local ID having the
maximum digits or below, in which it is assumed that the normal ID
has the number of digits n, the local ID has the number of digits n
and the local ID has the maximum number of digits m, it is
meaningless to issue the local ID having the number of digits n=m,
so that the local ID having the number of digits n>m is issued.
First, initialization is effected with the number of digits n of
the local ID 1 (C1), it is judged whether or not the number of
digits n of the local ID to be issued is equal to or less than the
maximum number of digits m (C2), and if the number of digits n of
the local ID is not equal to or less than the maximum number of
digits m, the local ID cannot be issued (C3), and processing of
issuing the local ID is terminated.
[0259] When the number of digits n of the local ID is equal to or
less than the maximum number of digits m, it is judged whether or
not there is any unused or invalid local ID (C4), and if there is
not any, the number of digits n of the local ID is increased by one
digit (n.rarw.n+1), and processing goes to step (C2). And, if there
is, its local ID and effective time are displayed. Then, the
effective time of the local ID to be issued and the normal ID
corresponding to the local ID are renewed (C7).
[0260] For example, in the fingerprint checking device 91 shown in
FIG. 23, a code or the like for the local ID requirement is entered
from the ten-key 95, the normal ID is entered, and a fingerprint is
affixed on the fingerprinting unit 93, the control unit 92 refers
to the file 98 to check the fingerprint, and if personal
identification is authenticated, refers to the local ID file 11,
and issues the local ID by steps (C1) to (C7) of FIG. 27. The
effective time at the time can be set according to the current time
indicated by the clock unit 96. And, the effective time and the
local ID are shown on the display unit 94, and it can be confirmed
by entering through the ten-key 95 or the like.
[0261] FIG. 28 is a flowchart of checking a fingerprint by entering
a local ID, in which when an n digit local ID is entered through
the ten-key 95 (D1), the control unit 92 refers to a local ID file
101 to read effective time information corresponding to the entered
local ID, reads the current time information from the clock unit
96, and judges whether or not the entered local ID is before the
effective time (D2).
[0262] If the effective time has passed, a message "Effective time
has passed." is shown on the display unit 94 (D3), and processing
is terminated. And, if within the effective time, the normal ID
corresponding to the local ID is displayed on the display unit 94
(D4). Thus, it can be checked whether or not the entry of the local
ID is wrong. This step can be omitted, and the instructions for
fingerprinting can be displayed.
[0263] And, when a fingerprint is affixed on the fingerprinting
unit 93 (D5), the control unit 92 which identifies the normal ID
corresponding to the local ID reads registered fingerprint data
corresponding to the normal ID from the fingerprint dictionary file
99, checks it with the affixed fingerprint, and if the checked
result is NG, displays it on the display unit 94, and terminates
processing, but if the checked result is OK, outputs the result of
personal identification (D7), and sends an unlocking signal
corresponding to the electric lock from the control output unit 97
for example.
[0264] The present invention is not limited to the above-described
embodiments. For example, in the local ID registering process shown
in FIG. 25, effective time can be set. Similarly, in the local ID
issuing process shown in FIG. 27, an arbitrary local ID is entered,
it is judged by the control unit 92 whether or not the pertinent
local ID has been issued, the judged result is displayed on the
display unit 94, and the entered local ID can be set in the local
ID file in correspondence with the normal ID, or the entering can
be made again. And, the registered fingerprint data stored in the
fingerprint dictionary file 99 is linked with the normal ID stored
in the personal information file 100, so that the local ID set in
the local ID file and the normal ID are linked, the normal ID is
determined from the entered local ID, the registered fingerprint
data is read according to the normal ID, so that the fingerprint
can be checked. But, by directly linking the local ID with the
registered fingerprint data, the registered fingerprint data
corresponding to the entered local ID can be read from the
fingerprint dictionary file 99 to check the fingerprint.
Embodiment 7
[0265] FIG. 29 is a flowchart of the embodiment of a fingerprint
registering method according to the present invention, in which (1)
to (15) show steps of registering a fingerprint. The fingerprint
registering method will be described with reference to the
structure shown in FIG. 45.
[0266] First, when registering of a fingerprint is started, it is
judged whether or not fingerprinting has been made (1), if the
average level in a prescribed range of the image signal by a
fingerprint image pickup unit 111 is equal to or above a prescribed
value, it is judged that fingerprinting has been made, and
multivalued fingerprint image data obtained by A/D-converting the
pictured image signal by an interface 115 is written into a
multivalued image memory 117 (2). Multivalued image data in the
content of the multivalued image memory 117 is binarized and
written into a binarized image memory 118 (3), and the binarized
image data in the content of the binarized image memory 118 is
copied into a binarized image save memory 119 (4).
[0267] Then, it is judged whether or not the registering operation
is for the first time (5), and if it is the first time, processing
goes to thinning processing (8), the binarized image data in the
content of the binarized image memory 118 is thinning-processed to
change the ridge lines of the fingerprint into thin lines and
written into a thinning-processed image memory 110, the
thinning-processed image data is used to extract minutiae of ending
points or bifurcation points of ridge lines, the extracted minutia
points (coordinate information) are written into a minutia list
memory 111 (9), the minutiae in a prescribed range, e.g., 0.5 mm,
are deleted as pseudo minutiae from the minutia list memory 111
(10).
[0268] And, it is judged whether or not the remaining minutiae are
equal to or above a prescribed number (11), and if they are equal
to or above the prescribed number, the image at the minutia part is
taken out of the binarized image save memory 119 based on the
coordinate information of minutiae and written into a nonvolatile
memory 112 for registering data (12). Thus, the fingerprint
registering process is completed (13).
[0269] If the number of minutiae is less than the prescribed
number, it is judged whether or not the number of registering
operations is for the third time (13), and if it is the third time,
registering is determined as failure. This number of times may be
set to four or five. And, if it is not the third time, processing
goes to step (1), and fingerprinting and registering steps (1) to
(4) are performed. And, in this case, when the registering is not
the first time in step (5) and the fingerprint image is judged to
be defective, the spatial filtering is effected on the multivalued
image data in the content of the multivalued image memory 117 (6).
The multivalued image data undergone the spatial filtering is
written into the multivalued image memory 117, and the content of
the multivalued image memory 117 is renewed.
[0270] The above-described spatial filtering judges the direction
of ridge lines and processes to connect the spaces of a prescribed
number of picture elements or below in the direction of ridge
lines. For example, the multivalued image data is binarized, one
screen is divided into block areas having a prescribed number of
picture elements, the direction of ridge lines in each block area
is judged according to the picture element arrangement pattern in
each block area, and the prescribed number of picture elements is
expanded in the direction of ridge lines with respect to the
multivalued image data to connect cracks or the like. Therefore,
for example, the cracks in the multivalued image shown in FIG.
50(A) are connected as marked by f in FIG. 50(B) by the spatial
filtering.
[0271] The multivalued image data which is through the spatial
filtering in the multivalued image memory 7 is binarized and
written into the binarized image memory 9 (7). Therefore, the
content of the binarized image memory 9 written in step (3) is
renewed. And, processing goes to step (8), and thinning processing,
extraction of minutiae and deletion of pseudo minutiae are
performed in steps (8) to (10), it is judged whether or not the
remaining number of minutiae is equal to or above a prescribed
number (11), and if it is so, the image at the minutia points is
taken out of the binarized image save memory 119 based on the
coordinate information of minutiae and written into the nonvolatile
memory 112 for registering data (12). Thus, the fingerprint
registering is completed (13).
[0272] If the number of remaining minutiae is not equal to or more
than the prescribed number, it is judged whether or not the number
of registering times is third (14), and if not, processing goes to
step (1). If it is the third time, it is determined as registering
failure (15). This number of registering times can be identified
easily by providing a simple-structured counter.
[0273] When the pictured fingerprint image is relatively good,
e.g., as shown in FIG. 46 (A), there are partial cracks but the
prescribed number of minutiae can be obtained by deleting such
cracks as pseudo minutiae, then the normal minutiae are registered,
so that the fingerprint checking rate can be improved.
[0274] When the pictured fingerprint image is not good, e.g., when
the multivalued image shown in FIG. 50(A) is binarized and
thinning-processed to extract minutiae, the number of pseudo
minutiae increases and the prescribed number or more of minutiae
cannot be obtained by deleting the pseudo minutiae, then the
spatial filtering is performed to obtain the multivalued image as
shown in FIG. 50(B), for example. Then, it is binarized and
thinning-processed to extract the minutiae. In this case, the
number of pseudo minutiae is decreased, the deletion of the normal
minutiae by the pseudo minutia deleting process can be avoided, a
probability of obtaining the prescribed number or more of minutiae
is enhanced, and a failure in registering the fingerprint can be
prevented.
[0275] The prescribed number of minutiae in step (11) can be set
to, e.g., 10 to 20, and it can be selected in accordance with the
accuracy of fingerprint checking. The repeating frequency of
registering operation, when the number of remaining minutiae is not
equal to or more than the prescribed number, can be increased as
required because identification can be made by means of a counter
as described above.
Industrial Applicability
[0276] The fingerprint registering method and fingerprint checking
device according to the present invention have advantages that the
average number of pseudo minutiae in registering windows is
determined at the time of registering a fingerprint, the average
number of pseudo minutiae is small when the fingerprint image has a
good image quality while it is large when the image quality is not
good, so that a numerical value can be used to indicate whether or
not the fingerprint image is good; when it is equal to or less than
a threshold, the fingerprint image can be judged to be
registerable, and the probability of matching between the
registered fingerprint with the affixed fingerprint is not lowered
with the lapse of time.
[0277] And, even when multiple number of fingers are registered and
all fingerprint images are NG because the average number of pseudo
minutiae exceeds the threshold, a finger having the minimum average
number of pseudo minutiae can be selected as the best finger and
its fingerprint can be registered, so that by automatically
selecting the best finger among fingers having chaps or many
wrinkles, the application range of fingerprint checking can be
expanded and the fingerprint checking can be made more
accurate.
[0278] The fingerprint registering method and fingerprint checking
entrance/exit control system according to the present invention
requires to use a fingerprint registering key to register the
fingerprints of at least two supervisors in the fingerprint
registering device, allows to register a new fingerprint of a
person by the fingerprint registering key and the matching of the
fingerprints of the supervisors, and can be operated for other
menus such as registering, renewal and deletion of a fingerprint
for entrance/exit control and collection of entrance/exit record
under double guards by the fingerprint registering key and the
fingerprint matching of the supervisors, thereby improving security
for entrance/exit control.
[0279] As to the supervisors, in renewing or deleting an attribute,
when the remaining supervisor is one or less than a prescribed
number, a request for renewing or deleting the attribute is
rejected, so that the supervisors who are required at the time of
registering, renewing or deleting a fingerprint are firmly secured,
so that the fingerprint checking entrance/exit control system can
be operated smoothly.
[0280] The fingerprint checking method according to the invention
detects the direction of respective picture elements in respective
blocks of a binarized fingerprint image by a direction detecting
mask, converts the number of picture elements having picture
elements added to correspond to the direction into a vector, adds
respective vectors to determine respective direction components,
determines the vector direction which becomes the maximum added
value as the ridge line direction of the pertinent block, and can
detect the ridge line direction for each block according to the
flow of ridge lines as compared with prior art which judges as the
ridge line direction a direction in which the number of picture
elements merely corresponding to a direction is maximum. Therefore,
when the spatial filtering is performed based on the ridge line
direction to provide a multivalued image and it is binarized, the
minutiae of the fingerprint can be accurately extracted from the
binarized image, so that it is advantageous in improving the
accuracy of checking a fingerprint.
[0281] The fingerprint checking method according to the present
invention produces a conversion key number s based on an entered
key number k and a content d at the n-th byte of registered
fingerprint data, and inserts the conversion key number s at the
m-th byte of the registered fingerprint data to store in a file, so
that even when a fingerprint is registered by using the same key
number k, it is substantially impossible to find where the
conversion key number s is inserted when the values n, m are not
known. Accordingly, the key number for checking a fingerprint does
not match with respect to alteration or the like of fingerprint
registering data, and it is advantageous in improving reliability
in view of the entrance/exit control by checking a fingerprint and
the operation control of the device or the like.
[0282] The fingerprint checking entrance/exit control system
according to the present invention is an entrance/exit control
system for distributed processing in which a host device and a
plurality of gates are connected through a line and fingerprint
checking is effected by each gate fingerprint checking unit,
wherein registered fingerprint data is renewed by affixed
fingerprint data at the time of personal identification, a time
stamp for indicating the pertinent time is added and kept, renewal
registered fingerprint data is sent upon a periodical requirement
from the host device, the host device refers to the time stamp
according to the collected renewal registered fingerprint data to
renew the fingerprint dictionary file, and renewal registered
fingerprint data corresponding to an ID is sent to the gates set to
correspond to the ID, so that it has an advantage that registered
fingerprint data at respective parts can be kept as the same.
[0283] The fingerprint checking device according to the present
invention has advantages to allocate a local ID having the number
of digits smaller than that of a normal ID to simplify the entry
operation in checking a fingerprint and to improve operability.
And, by setting effective time for the local ID, the local ID
allocated to a person who often uses temporarily can be allocated
to other persons after the lapse of effective time, thus the local
ID having the less number of digits can be used effectively.
[0284] The fingerprint registering method according to the present
invention processes assuming that the fingerprint image is good in
a first fingerprint registering operation, and if the number of
minutiae remaining after deleting pseudo minutiae is less than a
prescribed number, judges that the fingerprint image is NG, and
operates to register again. In such a case, the spatial filtering
is effected to make a fingerprint image which has a less number of
pseudo minutiae, so that the finger registering operation seldom
fails and the fingerprint matching rate can be improved by
registering normal minutiae.
* * * * *