U.S. Patent Number 5,631,971: "Vector Based Topological Fingerprint Matching"
Abstract: A fingerprint recognition and retrieval system in which the positions of fingerprint minutiae points and an index number for each minutiae point are recorded in a storage medium. The local ridge flow direction in the vicinity of each minutiae point defined by ridge endings and ridge bifurcations is determined and a generating line is projected at an angle to the local ridge flow direction. The generating line has a length sufficient to span a predetermined number of ridges to each side of each of the minutiae points. Each ridge is traced, in two directions, from the point of crossing of the projected generating line along any crossed ridge line. The first occurring topological event is assigned a type code (f) to the topological event. A topological event code vector is generated for each minutiae comprising an ordered sequence of topological type codes encountered during the tracing and any associated minutiae reference numbers and sets of the vectors are stored in a machine searchable database. The matching algorithm systematically develops connected clusters of minutiae points within an unknown one of the fingerprints for which there exists a matching cluster of minutiae points within the fingerprint under comparison and wherein the topological relationships among the set of minutiae within the matching clusters are substantially identical.
Filing Date: July 15th, 1994 [20 Claims]
Google Patents No: 5631971
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August 4th, 1994
South Korea, Patent Number 76007: "Fingerprint Recognition and Retrieval System"
Filing Date: Application number 700330, April 16th, 1987
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June 12th, 1990
Canadian Patent Number 1270332: "Fingerprint Recognition and Retrieval System"
Abstract: The invention relates to fingerprint coding and recognition and retrieval systems based on generally invarying topological irregularities, characteristics or minutiae (which terms are used interchanegeably herein) of fingerprints. The term "fingerprint" or "print" is used in reference to the epidermal ridge lilnes of the ten fingers of the human hand, palm prints, toe and sole prints of humans wherein such epidermal ridge lines and characteristic features thereof are in patterns unique to a particular individual....
...the soft elastic nature of human skin causes substantial variation of the spatial descriptions of successive impressions of the same fingerprint. Consequentially, spatially based coding systems used for forming machine searchable databases have inherent inaccuracies...
Topological coding schemes provide concise digital codes that provide a more economical and reliable basis for ten print identification systems...I suggest comparison methods based on topological coding of prints in which a topology based coding system for recording and comparing minutiae used vector arrays generated from topologically based coding of fingerprints...etc.
Filing Date: Application number 516,052, August 15th, 1986 [85 Claims]
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March 28th, 1989
U.S. Patent Number 4,817,183: "Fingerprint Recognition and Retrieval System"
Abstract: Fingerprints are scanned by a scanning system (13). Topological systems for coding and comparing fingerprints are described including a system for recording a description of fingerprints. In a preferred embodiment, a central point of the fingerprint is selected as a center of rotating scan line. The scan line is rotated to different topological characteristics. A code (T) representing the type of irregularity is recorded (16, 17). A measure (M) of the scanning position when encountering the irregularity is made (16,17). In the case of a rotating scan line the angular cordinate (θ) is recorded. The ridge count (R) (16) is also recorded. A list of coordinate sets (T, θ, R) specifies the topology of a sector. For fragmentary prints similar coordinate sets are generated. A fourth coordinate can be added corresponding to the radial distance (D) (16). A full set of coordinates (T, θ, R, D) gives a complete topological and spatial description of a fingerprint. Comparison of fingerprints can then be conducted by a computer (20).
REFERENCE TO RELATED APPLICATIONS FINGERPRINT RECOGNITION AND RETRIEVAL SYSTEM BACKGROUND AND BRIEF DESCRIPTION OF THE INVENTION. This is a divisional application of U.S. Ser. No. 875,023, filed Aug. 16, 1986 and entitled "FINGERPRINT RECOGNITION RETRIEVAL SYSTEM", now U.S. Pat. No. 4,747,147, which is a continuation-in-part of U.S. Ser. No. 771,188, filed Sept. 3, 1985, now abandoned, which is a continuation-in-part of U.S. Ser. No. 766,331, filed Aug. 16, 1985, also abandoned.
Filing Date: April 1st, 1987 [2 Claims]
Google Patents No: 4817183
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May 24th, 1988
U.S. Patent Number 4,747,147: "Fingerprint Recognition and Retrieval System"
Abstract: Fingerprints are scanned by a scanning system (13). Topological systems for coding and comparing fingerprints are described, including a system for recording a description of fingerprints. In a preferred embodiment, a central point of the fingerprint is selected as a center of rotating scan line. The scan line is rotated to different topological characteristics. A code (T) representing the type of irregularity is recorded (16, 17).A measure (M) of the scanning position when encountering the irregularity is made (16, 17). In the case of a rotating scan line the angular coordinate (θ) is recorded as the measure (M) of scanning position. The ridge count (R) (16) is also recorded. A list of coordinate sets (T, θ, R) specifies the topology of a sector. For fragmentary prints similar coordinate sets are generated. A fourth coordinate can be added corresponding to the radial distance (D) (16). A full set of coordinates (T, θ, R, D) gives a complete topological and spatial description of a fingerprint. Comparison of fingerprints can then be conducted by a computer (20)
Filing Date: January 16th, 1986. [86 Claims]
Google Patents No: 4747147
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August 13th, 1986
Australian Patent Number 587152: "Fingerprint Recognition and Retrieval System"
Abstract: Fingerprints are scanned by a scanning system (13). Topological systems for coding and comparing fingerprints are described, including a system for recording a description of fingerprints. In a preferred embodiment, a central point of the fingerprint is selected as a center of rotating scan line. The scan line is rotated to different topological characteristics. A code (T) representing the type of irregularity is recorded (16, 17).A measure (M) of the scanning position when encountering the irregularity is made (16, 17). In the case of a rotating scan line the angular coordinate (θ) is recorded as the measure (M) of scanning position. The ridge count (R) (16) is also recorded. A list of coordinate sets (T, θ, R) specifies the topology of a sector. For fragmentary prints similar coordinate sets are generated. A fourth coordinate can be added corresponding to the radial distance (D) (16). A full set of coordinates (T, θ, R, D) gives a complete topological and spatial description of a fingerprint. Comparison of fingerprints can then be conducted by a computer (20)
Filing Date: Application number 62236, August 13th, 1986. [1 Claim]. Based on International Application Published under the Patent Cooperation Treat (PCT). International Publication Number
WO 87/01224. International Publication Date: February 26th, 1987.
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