Class FingerprintMatcher

    • Method Detail

      • match

        public double match​(FingerprintTemplate candidate)
        Matches candidate fingerprint to probe fingerprint and calculates similarity score. Candidate fingerprint in candidate parameter is matched to probe fingerprint previously passed to FingerprintMatcher(FingerprintTemplate) constructor.

        Returned similarity score is a non-negative number that increases with similarity between probe and candidate fingerprints. Application should compare the score to a threshold with expression (score >= threshold) to arrive at boolean match/non-match decision. Threshold 10 corresponds to FMR (False Match Rate, see Biometric Performance and Confusion matrix) of 10%, threshold 20 to FMR 1%, threshold 30 to FMR 0.1%, and so on.

        Recommended threshold is 40, which corresponds to FMR 0.01%. Correspondence between threshold and FMR is approximate and varies with quality of fingerprints being matched. Increasing threshold rapidly reduces FMR, but it also slowly increases FNMR (False Non-Match Rate). Threshold must be tailored to the needs of the application.

        This method is thread-safe. Multiple threads can match candidates against single FingerprintMatcher.

        candidate - fingerprint template to be matched with probe fingerprint represented by this FingerprintMatcher
        similarity score between probe and candidate fingerprints
        NullPointerException - if candidate is null
      • memory

        public int memory()
        Estimates memory footprint of this object. This is a deep estimate, including all nested objects. The estimate should be fairly accurate on all commonly used JVMs.
        estimated memory footprint of this object in bytes