Minutia data extraction in fingerprint identification

• US 5,109,428 A
• Filed: 12/06/1989
• Issued: 04/28/1992
• Est. Priority Date: 12/06/1988
• Status: Expired due to Term

• Current Assignee: Fujitsu Limited
• Original Assignee: Fujitsu Limited
• Inventors: Ikeda, Hiroyuki, Shinzaki, Takashi, Yahagi, Hironori, Igaki, Seigo, Yamagishi, Fumio
• Primary Examiner(s): Boudreau, Leo H.
• Assistant Examiner(s): Stellrecht, Barry
• Application Number:
  US07/446,660
• Time in Patent Office: 874 Days
• Field of Search: 382/4, 382/5, 356/71
• US Class Current: 382/125
• CPC Class Codes: A61B 5/1172 using fingerprinting
• CPC Class Codes: G06V 40/1365 Matching; Classification
• CPC Class Codes: G07C 9/37 using biometric data, e.g. fingerprints, iris scans or voice recognition

Abstract

An apparatus used in fingerprint identification for extracting minutia data from fingerprint image data. An optical sensor unit optically produces a sequence of fingerprint image data during a single operation of pressing a fingerpad onto an inspection plate in a direction substantially transverse to the plate and with increasing pressure over a time interval. A data storing unit stores the produced fingerprint image data in the form of a sequence of fingerprint image data obtained during the single operation of pressing the fingerpad onto the inspection plate. The stored fingerprint image data is utilizable for identification of the fingerprint.

Claims

1. An apparatus used in a fingerprint identification for extracting minutia data from fingerprint image data optically sensed from a fingerpad and registering data for fingerprint identification based on the extracted minutia data, said apparatus comprising:

optical sensor means, including an inspection plate having a surface, for optically producing a sequence of fingerprint image data frames during a single operation of pressing a fingerpad in a substantially transverse direction onto the surface of the inspection plate and with progressively increasing pressure over a time interval, the single operation creating an initial, soft contact of a first portion of the fingerprint on a first portion of the inspection plate surface and progressively more firm contact fingerprint on a progessively increasing portion of the of a progressively increasing portion of the inspection plate surface and the optical sensor means producing the sequence of the fingerprint image data frames at spaced time increments over the time interval;

processing means for identifying and extracting minutia data and respectively associated minutia coordinate data from each of the sequence of fingerprint image data frames and for selecting, therefrom, minutia data for storage in accordance with the order of the respective frequencies of appearance of the minutia data, for the respectively corresponding minutia data coordinates thereof, as identified and extracted from the sequence of fingerprint image data frames; and

data storing means for storing the selected fingerprint minutia data, as extracted from the fingerprint image data of the sequence of fingerprint image data frames produced during the single operation of pressing the fingerpad onto the inspection plate, the stored fingerprint image minutia data being utilizable for identification of the fingerprint.

2. A method used in a fingerprint identification for extracting minutia data from fingerprint image data optically sensed from a fingerpad and registering data for fingerprint identification based on the extracted minutia data, said method comprising the steps of:

optically producing a sequence of fingerprint image data frames during a single operation of pressing a fingerpad in a substantially transverse direction onto the surface of an inspection plate and with progressively increasing pressure over a time interval, the single operation creating an initial, soft contact of a first portion of the fingerprint on a first portion of the inspection plate surface and progressively more firm contact of a progressively increasing portion of the fingerprint on a progressively increasing portion of the inspection plate surface and the sequence of the fingerprint image data frames being produced at spaced time increments over the time interval;

identifying and extracting minutia data and respectively associated minutia coordinate data from each of the sequence of fingerprint image data frames and selecting, therefrom, minutia data for storage in accordance with the order of the respective frequencies of appearance of the minutia data, for the respectively corresponding minutia data coordinates thereof, as identified and extracted from the sequence of fingerprint image data frames; and

storing, in a storage device, the selected fingerprint minutia data extracted from the fingerprint image data of the sequence of fingerprint image data then produced during the single operation of pressing the fingerpad onto the inspection plate, the stored fingerprint image minutia data being utilizable for identification of the fingerprint.

3. A method for identifying a fingerprint based on extractions of minutia data from fingerprint image data optically sensed from a fingerpad, said method comprising the steps of:

optically obtaining a sequence of frames of fingerprint image data for registration during a single operation of pressing a fingerpad onto an inspection plate in a direction substantially transverse to the plate and with progressively increasing pressure, over a time interval;

storing the obtained fingerprint image data for registration in a storage device in the form of a sequence of frames of fingerprint image data for registration;

extracting minutia data for registration, from the stored sequence of frames of fingerprint image data for registration;

storing the extracted minutia data for registration into a reference data file device in accordance with the order from the most frequently appearing minutia, in succession, to the least frequently appearing minutia;

optically obtaining a sequence of frames of fingerprint image data for comparison during a single operation of pressing the fingerpad in single direction onto the inspection plate;

storing the obtained fingerprint image data for comparison in the storage device in the form of a sequence of frames of fingerprint image data for comparison;

extracting minutia data for comparison from the stored sequence of frames of fingerprint image data for comparison;

comparing the minutia data for comparison, extracted from the stored sequence of frames of fingerprint image data for comparison, with the minutia data for registration, as stored in said reference data file device for determining points of coincidence therebetween; and

determining a coincidence between fingerprints, as respectively represented by the minutia data for comparison and the minutia data for registration, when the number of points of coincidence determined in accordance with said comparing step, and in relation to one frame of the fingerprint image data, is greater than a predetermined number.

4. A method according to claim 3, further comprising the steps of:

extracting a plurality of regional fingerprint image data from regions surrounding the region of the most frequently appearing minutia, in addition to the extraction of the most frequently appearing minutia; and

storing the extracted plurality of regional fingerprint picture image data in the reference data file device, in addition to the storing of the most frequently appearing minutia.