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Automated fingerprint classification/identification system and method

  • US 5,465,303 A
  • Filed: 11/12/1993
  • Issued: 11/07/1995
  • Est. Priority Date: 11/12/1993
  • Status: Expired due to Fees
First Claim
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1. An automated fingerprint classification and identification apparatus used to determine or verify the identity of an unknown person by comparing one or more of the person'"'"'s unknown fingerprints to known fingerprints stored in a data base, the apparatus comprising:

  • a fingerprint input subsystem, operable to create a digitized bit-map of the unknown fingerprint and to store said bit-map in a memory of said fingerprint subsystem;

    a template creation subsystem, coupled to said fingerprint input subsystem, operable to receive said bit-map of said unknown fingerprint and to create a digitized template based on locations of minutiae points in said bit-map;

    a classification subsystem, coupled to said fingerprint input subsystem and said template creation subsystem, operable to receive said bit-map and said template and to assign said unknown fingerprint to a primary Vucetich category based on visually distinct patterns present in said bit-map and digital information extracted from said template, said classification subsystem includes,(a) means for determining a central feature of said unknown fingerprint, wherein said central feature is the innermost point of said unknown fingerprint;

    (b) means for creating a bounding rectangle around said central feature;

    (c) means for determining whether said central feature is within a first valley, and if not, then moving said central feature upward until it is within said first valley;

    (d) means for generating a colored area by applying a floodfill algorithm to said unknown fingerprint in order to fill in said first valley and at least one valley adjacent to said first valley;

    (e) means for classifying said unknown fingerprint as a whorl if said colored area does not touch the border of said bounding rectangle or if said colored area touches the border of said bounding rectangle and at least half of said colored area is above said central feature;

    (f) means for classifying said unknown fingerprint as an arch if said colored area touches both sides of said bounding rectangle and approximately half of said colored area is right of said central feature and half of said colored area is left of said central feature; and

    (g) means for classifying said unknown fingerprint as a loop if said colored area touches only one side of said bounding rectangle, wherein said loop in an inside loop if said colored area is weighted on said left side and said loop in an external loop if said colored area is weighted on said right side;

    an image storage subsystem, coupled to said classification subsystem, said template creation subsystem, and said fingerprint input subsystem, operable to store said bit-map and said template in memory locations that correspond to the primary Vucetich category and also to store known bit-maps and templates of known bit-maps in memory locations that correspond to the primary Vucetich category; and

    a search subsystem, coupled to the image storage subsystem, operable to compare said template of said unknown fingerprint to templates of said known fingerprints that are of the same primary Vucetich category as said unknown fingerprint, and to produce a result indicating a probability that said unknown fingerprint is identical to one of said known fingerprints.

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