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US 10,255,477 B2Granted
Feature-based matcher for distorted fingerprint matching
AssigneeMorphoTrak, LLC
InventorsPeter Zhen-Ping Lo, Hui Chen
Life of this patent
Estimating the term…
Abstract
In one aspect, methods that use a novel representation, referred to as an octant feature vector (OFV), are used for matching distorted fingerprints. For instance, a feature-based matcher for distorted fingerprint matching may use a two-step local and global matching scheme to compare a set of feature vectors that are derived from minutiae of a reference fingerprint and a search fingerprint. The relative geometric relationships between the reference minutia and nearest minutiae may be derived and encoded into a feature vector based on orientation difference. The OFV is invariant to the rigid transformations and is insensitive to nonlinear distortions since the relative geometric relationships are independent from the rigid transformation.
Claims20
A method performed by one or more computers, the method comprising:
- receiving (i) search octant feature vectors associated with search minutiae extracted from a search fingerprint, and (ii) reference octant feature vectors associated with reference minutiae extracted from a reference fingerprint;
- for each search minutia included in the search minutiae:
- computing a first score that represents a feature difference between (i) a search octant feature vector that includes a particular search minutia and (ii) reference octant feature vectors that each include a reference minutia included in a first set of reference minutiae that are identified as being closest neighboring minutiae to the search minutia;
- computing a second score that represents a ratio of a number of paired mated minutiae included in the first set of reference minutiae relative to a number of paired unmated minutiae included in the first set of reference minutiae;
- determining, based on the first and second scores, a geometrically aligned region between the search fingerprint and the reference fingerprint;
- determining a set of globally aligned mated minutia pairs based on the geometrically aligned region between the search fingerprint and the reference fingerprint;
- for each mated minutia pair included in the set of globally aligned mated minutia pairs:
- computing a third score that represents a feature difference between (i) a search octant feature vector that includes a particular search minutia and (ii) reference octant feature vectors that each include a reference minutia included in a second set of reference minutiae that are identified as being closest neighboring minutiae to the search minutia in the geometrically aligned region;
- computing a fourth score that represents a ratio of a number of paired mated minutiae in the geometrically aligned region included in the second set of reference minutiae relative to a number of paired unmated minutiae in the geometrically aligned region included in the second set of reference minutiae;
- computing a match similarity score between the search fingerprint and the reference fingerprint based at least on combining the first score, the second score, the third score, and the fourth score;
- and
- providing the match similarity score for output to an automatic fingerprint identification system.
9 more elements
A system comprising:
- one or more processors;
- and
- one or more storage devices storing instructions that, when executed by the one or more processors, cause the one or more processors to perform operations comprising:
- receiving (i) search octant feature vectors associated with search minutiae extracted from a search fingerprint, and (ii) reference octant feature vectors associated with reference minutiae extracted from a reference fingerprint;
- for each search minutia included in the search minutiae:
- computing a first score that represents a feature difference between (i) a search octant feature vector that includes a particular search minutia and (ii) reference octant feature vectors that each include a reference minutia included in a first set of reference minutiae that are identified as being closest neighboring minutiae to the search minutia;
- computing a second score that represents a ratio of a number of paired mated minutiae included in the first set of reference minutiae relative to a number of paired unmated minutiae included in the first set of reference minutiae;
- determining, based on the first and second scores, a geometrically aligned region between the search fingerprint and the reference fingerprint;
- determining a set of globally aligned mated minutia pairs based on the geometrically aligned region between the search fingerprint and the reference fingerprint;
- for each mated minutia pair included in the set of globally aligned mated minutia pairs:
- computing a third score that represents a feature difference between (i) a search octant feature vector that includes a particular search minutia and (ii) reference octant feature vectors that each include a reference minutia included in a second set of reference minutiae that are identified as being closest neighboring minutiae to the search minutia in the geometrically aligned region;
- computing a fourth score that represents a ratio of a number of paired mated minutiae in the geometrically aligned region included in the second set of reference minutiae relative to a number of paired unmated minutiae in the geometrically aligned region included in the second set of reference minutiae;
- computing a match similarity score between the search fingerprint and the reference fingerprint based at least on combining the first score, the second score, the third score, and the fourth score;
- and
- providing the match similarity score for output to an automatic fingerprint identification system.
12 more elements
A non-transitory machine-readable data storage device that stores instructions that, when executed by data processing apparatus, cause the data processing apparatus to perform operations comprising:
- receiving (i) search octant feature vectors associated with search minutiae extracted from a search fingerprint, and (ii) reference octant feature vectors associated with reference minutiae extracted from a reference fingerprint;
- for each search minutia included in the search minutiae:
- computing a first score that represents a feature difference between (i) a search octant feature vector that includes a particular search minutia and (ii) reference octant feature vectors that each include a reference minutia included in a first set of reference minutiae that are identified as being closest neighboring minutiae to the search minutia;
- computing a second score that represents a ratio of a number of paired mated minutiae included in the first set of reference minutiae relative to a number of paired unmated minutiae included in the first set of reference minutiae;
- determining, based on the first and second scores, a geometrically aligned region between the search fingerprint and the reference fingerprint;
- determining a set of globally aligned mated minutia pairs based on the geometrically aligned region between the search fingerprint and the reference fingerprint;
- for each mated minutia pair included in the set of globally aligned mated minutia pairs:
- computing a third score that represents a feature difference between (i) a search octant feature vector that includes a particular search minutia and (ii) reference octant feature vectors that each include a reference minutia included in a second set of reference minutiae that are identified as being closest neighboring minutiae to the search minutia in the geometrically aligned region;
- computing a fourth score that represents a ratio of a number of paired mated minutiae in the geometrically aligned region included in the second set of reference minutiae relative to a number of paired unmated minutiae in the geometrically aligned region included in the second set of reference minutiae;
- computing a match similarity score between the search fingerprint and the reference fingerprint based at least on combining the first score, the second score, the third score, and the fourth score;
- and
- providing the match similarity score for output to an automatic fingerprint identification system.
9 more elements
Dependencies are inferred from the claim text.