Patent US5347616A successfully refreshed from Google Patents.
EP0125532A2
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EP
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Fingerprint verification method
Assignee: Fingermatrix Inc
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Filing: 1984-04-21
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Granted: —
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Expires: 2004-04-21
Abstract
Abstract An input fingerprint image consists of ones and zeros pixels representing light and dark pixels which in turn correspond to ridge and valley formations. This image is compared with a reference file fingerprint to verify the identity of the input fingerprint. The reference file has two relatively small segments which are subfields of the entire field of pixels that constituted the original fingerprint image for the individual involved. Two substantially larger domain sub- fields are extracted from the input fingerprint image. The center of each segment corresponds to the center of a respective one of the domains. Each segment is scanned over its corresponding domain to determine the position of maximum ones correlation and maximum zeros correlation between each segment and its corresponding domain. These four positions together with the correlation values associated with each of these four positions are subjected to various criteria to provide positive or negative verification of the input image relative to the reference file. These criteria include (a) positional closenes to one another, (b) exclusion of the positions from a predetermined border of the domain, (c) closeness of the correlation values of certain of the positions, and (d) magnitude of the sum of the ones correlations and zeros correlation for certain of the positions.
Inventors
- 👤 Michael Schiller
- 👤 Emily Ginsberg
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-09 17:27
CPC Classifications
G; G07; G07C; G07C9/00; G07C9/30; G07C9/32; G07C9/33; G06; G06V; G06V40/00; G06V40/10; G06V40/12; G06V40/1365; G07C9/37
Claims Analysis
Total Claims: 24
Claim 1
Independent Claim
181 words
The method of fingerprint verification by comparison of an enrollment file against an input file wherein each file is composed of a field of pixels having first and second values representing respectively fingerprint ridge and valley pixels, and wherein the enrollment file has at least first and second reference segment subfields from a reference fingerprint image, comprising the steps of: establishing at least first and second domain subfields from an input fingerprint image, each of said domains being substantially . larger than respective ones of the reference segment subfields, scanning the first reference segment across said first domain and scanning the second reference segment across said second domain to determine significant positions, said significant positions constituting locations of maximum correlation for each reference segment/domain pair between pixels having said first value and also locations of maximum correlation for each reference/segment domain pair between pixels having said second value, and verifying the input image from which said domains are extracted as corresponding to the fingerprint image from which the reference segments were extracted by subjecting said significant locations to pre-determined positional criteria.
Claim 2
Independent Claim
181 words
The method of fingerprint verification by comparison of an enrollment file against an input file wherein each file is composed of a field of pixels having first and second values representing respectively fingerprint ridge and valley pixels, and wherein the enrollment file has at least first and second reference segment subfields from a reference fingerprint image, comprising the steps of: establishing at least first and second domain subfields from an input fingerprint image, each of said domains being substantially . larger than respective ones of the reference segment subfields, scanning the first reference segment across said first domain and scanning the second reference segment across said second domain to determine significant positions, said significant positions constituting locations of maximum correlation for each reference segment/domain pair between pixels having said first value and also locations of maximum correlation for each reference/segment domain pair between pixels having said second value, and verifying the input image from which said domains are extracted as corresponding to the fingerprint image from which the reference segments were extracted by subjecting said significant locations to pre-determined positional criteria.
Claim 3
Dependent Claim
121 words
The method of claim 1 wherein said significant positions include at least: a first position being the position of said first reference segment in said first domain where the maximum correlation is found between pixels having said first value, a second position being the position of said first reference segment in said first domain where the maximum correlation is found between pixels having said second value, a third position being the position of said second reference segment in said second domain where the maximum correlation is found between pixels having said first value, and, a fourth position being the position of said second reference segment in said second domain where the maximum correlation is found between pixels having said second value.
Claim 4
Dependent Claim
43 words
The method of claim 2 wherein: the centers of said first and second reference segments have substantially the same positional location to the reference fingerprint image as do the centers of said first and second domains to the input fingerprint image being verified.
Claim 5
Dependent Claim
76 words
The method of claim 2 wherein said step of determining said four significant positions is performed by the steps of: systematically scanning each reference segment across the corresponding domain in a series of predetermined overlaping test locations, determining in each test location a score of ones pixel correlation and a score of zeros pixel correlation, and storing for reference the positions of maximum ones pixel correlation and maximum zeros pixel correlation for each reference segment/domain pair.
Claim 6
Dependent Claim
37 words
The method of claim 4 wherein said four significant positions are given x and y coordinates in terms of their locations within their respective domains, said four sets of coordinates being referenced to the same coordinate plane.
Claim 7
Dependent Claim
31 words
The method of claim 5 further comprising the step of: storing for reference the magnitudes of the ones correlation values and the zeros correlation values at each of said four positions.
Claim 8
Dependent Claim
31 words
The method of claim 5 wherein said step of verifying requires that three of said four significant positions be positioned, in said coordinate plane, within a pre-determined distance of one another.
Claim 9
Dependent Claim
38 words
the method of claim 7 wherein said step of verifying further requires that said three closely associated significant positions be a pre-determined distance away from the border of said coordinate plane based on the dimension of said domains.
Claim 10
Dependent Claim
50 words
The method of claim 7 wherein said step of verifying further requires that said maximum correlation value of said fourth significant position be within a predetermined magnitude or ratio of the correlation value of the same pixel value of the other significant position in the domain of said fourth position.
Claim 11
Dependent Claim
63 words
The method of claim 7 wherein said step of verifying further requires that one of said three of said significant positions within said predetermined distance which is in said first domain has a correlation sum that exceed a first threshold and that one of said three significant locations within said predetermined distance that is in said second domain also exceeds said first threshold.
Claim 12
Dependent Claim
63 words
The method of claim 9 wherein said step of verifying further requires that one of said three of said significant positions within said predetermined distance which is in said first domain has a correlation sum that exceed a first threshold and that one of said three significant locations within said predetermined distance that is in said second domain also exceeds said first threshold.
Claim 13
Dependent Claim
37 words
The method of claim 10 where said step of verifying further requires that the correlation value of one of the two positions that exceeds said first threshold also exceeds a second threshold greater than said first threshold.
Claim 14
Dependent Claim
37 words
The method of claim 11 where said step of verifying further requires that the correlation value of one of the two positions that exceeds said first threshold also exceeds a second threshold greater than said first threshold.
Claim 15
Dependent Claim
70 words
The method of claim 1 further comprising the steps of: establishing said reference segment sub- fields by first establishing an initial set of reference segment subfields for a subject finger, then verifying repeated applications of said subject finger in accordance with the method of claim 1, and retaining said initial set in the reference file only if positive verification is obtained in a pre- determined number of said repeated applications.
Claim 16
Dependent Claim
69 words
The method of claim 7 further comprising the steps of: establishing said reference segment sub- fields by first establishing an initial set of reference segment subfields for a subject finger, then verifying repeated applications of subject finger in accordance with the method of claim 1, and retaining said initial set in the reference file only if positive verification is obtained in a pre- determined number of said repeated applications.
Claim 17
Dependent Claim
78 words
The method of claim 1 further comprising the steps of: applying said steps of establishing domain subfields, scanning and verifying to a first input fingerprint image and to a second input fingerprint image, said first and second images being taken from different first and second fingers, and providing identification of the subject having said first and second fingerprint images if and only if said step of verifying is successfully completed in connection with both of the fingerprint images.
Claim 18
Dependent Claim
78 words
The method of claim 7 further comprising the steps of: applying said steps of establishing domain subfields, scanning and verifying to a first input fingerprint image and to a second input fingerprint image, said first and second images being taken from different first and second fingers, and providing identification of the subject having said first and second fingerprint images if and only if said step of verifying is successfully completed in connection with both of the fingerprint images.
Claim 19
Dependent Claim
43 words
The method of claim 16 further comprising the steps of: applying said steps of establishing, scanning and verifying to separate applications of the subject's fingerprint images, and . providing identification if any one of the applications is verified by said step of verifying.
Claim 20
Dependent Claim
42 words
The method of claim 17 further comprising the steps of: applying said steps of establishing, scanning and verifying to separate applications of the subject's fingerprint images, and providing identification if any one of the applications is verified by said step of verifying.
Claim 21
Dependent Claim
188 words
In the system of verifying an input fingerprint image by comparision of an enrollement file against an input file wherein each file is composed of a field of pixels having first and second value representing respectively fingerprint ridge and valley pixels, and where the enrollment file has at least first and second reference segment subfields from a reference fingerprint image, comprising: means to establish at least first and second domain subfields from an input fingerprint image, each of said domains being substantially larger than each respective reference segment subfield, scanning means for scanning the first reference segment across said first domain and scanning the second reference segment across said second domain to determine significant positions, said significant positions constituting locations of maximum correlation for each reference/segment domain pair between pixels having said first value and also locations of maximum correlation for each reference/segment domain pair between pixels having said second value, and means to verify the input image from which said domains are extracted as corresponding to the fingerprint image from which the reference segments were extracted by subjecting said significant locations to a pre- determined positional criteria.
Claim 22
Dependent Claim
188 words
In the system of verifying an input fingerprint image by comparision of an enrollement file against an input file wherein each file is composed of a field of pixels having first and second value representing respectively fingerprint ridge and valley pixels, and where the enrollment file has at least first and second reference segment subfields from a reference fingerprint image, comprising: means to establish at least first and second domain subfields from an input fingerprint image, each of said domains being substantially larger than each respective reference segment subfield, scanning means for scanning the first reference segment across said first domain and scanning the second reference segment across said second domain to determine significant positions, said significant positions constituting locations of maximum correlation for each reference/segment domain pair between pixels having said first value and also locations of maximum correlation for each reference/segment domain pair between pixels having said second value, and means to verify the input image from which said domains are extracted as corresponding to the fingerprint image from which the reference segments were extracted by subjecting said significant locations to a pre- determined positional criteria.
Claim 23
Dependent Claim
28 words
The combination of claim 20 further comprising: first storage means for storing the maximum ones correlation positions and maximum zeros correlation position for each of reference segment/domain pair.
Claim 24
Dependent Claim
27 words
The combination of claim 21 further comprising: second storage means for storing the magnitude of the correlation values for each position stored in said first storage means.
References Cited (Backward Citations)
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