09/27 Notes

Verification Errors

Metrics to check

  1. Area under Curve (AUC)
  2. Equal Error Rate (EER) = where x = y line intersects error curve (for DET)
  3. D-Prime
  4. False NonMatch Rate (FNMR)
  5. TMR = 1 - FNMR (True match rate)

Identification Error Rates

Database == Gallery

Gallery has several identities residing in it

Each identity has a template = set of features that denote identity

A probe gets a score from each identity, so N scores

Errors

  1. False Positive Identification Rate (FPIR) = when probe matches when not in system
    • Need to know N, eata, top K matches
  2. False Negative Identification Rate (FNIR) = when probe does not match id that is in system
    • Need to know N, eata, top K matches

For top K matches

Generate cumulative match characteristics Graph (CMC)

y = TIR x = Rank = K

Shows you what percent of probes are correctly matched from rank 1 to K

In a closed set, each probe has a matching identity, we want to know what rank we find it at

In a open set, it may not have an identity