Fingerprint imaging and quality characterization
First Claim
Patent Images
1. A fingerprint imaging system comprising:
- a fingerprint sensor configured to generate a fingerprint image of a fingerprint; and
a processor configured to process the fingerprint image, the processor operable to;
generate a ridge flow map based on, at least in part, the fingerprint image, the ridge flow map comprising ridge flow vectors characterizing the fingerprint;
generate a multi-layer decomposition of the ridge flow map based on, at least in part, the ridge flow vectors, the decomposition comprising;
a first-order residual map comprising first-order residuals for the ridge flow vectors, based on, at least in part, a first-order set of adjacent ridge flow vector values; and
a second-order residual map comprising second-order residuals for the ridge flow vectors, based on, at least in part, a second-order set of the adjacent first-order values;
wherein;
the processor is further operable to characterize a quality of the fingerprint image, based on, at least in part, the first and second order residuals;
the first-order residuals comprise a difference between respective ridge flow vector values, and an average value of the first-order set of adjacent ridge flow vector values; and
the second-order residuals comprise a difference between respective average values of the first-order set, and an average value of the second-order set of adjacent first-order values.
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Abstract
A fingerprint processing system comprises a fingerprint sensor configured to generate an image of a fingerprint, and a processor configured to process the fingerprint image. The processor is operable to generate a ridge flow map comprising ridge flow vectors characterizing the fingerprint, and a multi-layer decomposition based on the ridge flow vectors. The decomposition includes at least first and second-order residuals, based on the ridge flow vectors, and the processor is operable to characterize a quality of the fingerprint image, based on the residuals.
70 Citations
19 Claims
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1. A fingerprint imaging system comprising:
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a fingerprint sensor configured to generate a fingerprint image of a fingerprint; and a processor configured to process the fingerprint image, the processor operable to; generate a ridge flow map based on, at least in part, the fingerprint image, the ridge flow map comprising ridge flow vectors characterizing the fingerprint; generate a multi-layer decomposition of the ridge flow map based on, at least in part, the ridge flow vectors, the decomposition comprising; a first-order residual map comprising first-order residuals for the ridge flow vectors, based on, at least in part, a first-order set of adjacent ridge flow vector values; and a second-order residual map comprising second-order residuals for the ridge flow vectors, based on, at least in part, a second-order set of the adjacent first-order values; wherein; the processor is further operable to characterize a quality of the fingerprint image, based on, at least in part, the first and second order residuals; the first-order residuals comprise a difference between respective ridge flow vector values, and an average value of the first-order set of adjacent ridge flow vector values; and the second-order residuals comprise a difference between respective average values of the first-order set, and an average value of the second-order set of adjacent first-order values. - View Dependent Claims (2, 3, 4, 5, 6)
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7. A method comprising:
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acquiring a fingerprint image; generating an orientation map based on, at least in part, the fingerprint image, the orientation map comprising a set of vector values characterizing a ridge flow pattern of the fingerprint image; generating a multi-layer decomposition of the orientation map, the decomposition comprising at least first and second order residuals of the vector values, the first order residuals based on, at least in part, the orientation map and the second order residuals based on, at least in part, a first order transformation of the orientation map; and characterizing a quality of the fingerprint image, based on, at least in part, a measure of variance of the residuals;
wherein;the first order residuals comprise a difference between respective ridge flow vector values, and an average value of the first order set of adjacent ridge flow vector values; and the second order residuals comprise a difference between respective average values of the first-order set, and an average value of the second-order set of adjacent first-order values. - View Dependent Claims (8, 9, 10, 11, 12, 13, 14, 15)
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16. A mobile device comprising:
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a control mechanism configured for controlling operation of the mobile device; a fingerprint sensor integrated with the control mechanism, the fingerprint sensor configured for capturing a fingerprint image of a user in operation of the mobile device; a processor in signal communication with the fingerprint sensor, the processor operable to; generate a ridge flow map based on, at least in part, the fingerprint image, the ridge flow map comprising ridge flow vectors characterizing the fingerprint image; decompose the ridge flow map into a multi-layer residual mapping, the residual mapping including at least first and second order residuals based on, at least in part, the ridge flow vectors; and characterize an image quality of the fingerprint image, based on, at least in part, a measure of variance of the residuals; wherein; the mobile device is configured for identification and authorization of the user, based at least in part on the image quality; and the first order residuals comprise a difference between respective ridge flow vector values, and an average value of the first order set of adjacent ridge flow vector values; and the second order residuals comprise a difference between respective average values of the first-order set, and an average value of the second-order set of adjacent first-order values. - View Dependent Claims (17, 18, 19)
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Specification