Page 295 - Automated Fingerprint Identification Systems (AFIS)
P. 295

280  AUTOMATED FINGERPRINT IDENTIFICATION SYSTEMS



                              APPENDIX C—EFTS

                              ISSUES DOCUMENTED IN JULY 1997

                              Existing Scope of EFTS:

                               1. SRT “No Hit” Condition: There is no specification in the FBI-EFTS docu-
                                  ment on how to return a No-Hit message in response to a Tenprint Image
                                  Search (TPIS). Does one merely include the words “No Hit” in the 2.064
                                  field (the mandatory field normally containing the candidate list)? In our
                                  testing, we had pre-sent cards to all vendors, so that a No Hit condition
                                  would not occur. Resolution: Still pending.
                               2. DAI Size Discrepancy:  The EFTS lists contradictory size specifications
                                  of the Destination Agency Identifier (DAI) and Originating Agency Iden-
                                  tifier (ORI) found in Type-1 records. In the ANSI-NIST standard and the
                                  EFTS, it says, “The size and data content of this field shall be defined by
                                  the user and be in accordance with the receiving agency.” However, the
                                  EFTS goes on to say, “This field shall be a ten-byte [or nine-byte respec-
                                  tively] alphanumeric field.” So if this in fact is true, and since the DAI is
                                  merely the other person’s ORI, what constitutes the extra byte? Resolution:
                                  Still pending.
                               3. ORI/DAI Size Conflict with ANSI-NIST: The EFTS specifies a size for the
                                  ORI and DAI, but the ANSI-NIST standard says that “the size and data
                                  content of this field shall be defined by the user and be in accordance with
                                  the receiving agency.” Which is correct? Resolution: Still pending.
                               4. Candidate Scores: Do we need another field in Type-2 Record for scores of
                                  candidates? Currently, scores are not returned with the candidates. Reso-
                                  lution: Still pending.
                               5. Score Meaning: Currently, all vendors have different methods and values
                                  for scoring, e.g., a score of 1,000 with Vendor A may not have the same sig-
                                  nificance as with Vendor B. Also, a score of 1,000 is not necessarily “twice
                                  as good” as a score of 500. We need to further explore possible uniformity
                                  and understanding of the scoring process. NOTE: This point is of interest
                                  only if it’s decided to return the scores with the candidate lists. Resolution:
                                  Still pending.
                               6. NTR Update: Nominal Transmitting Resolution (NTR) needs to be
                                  updated. The Native Scanning Resolution (NSR) has a minimum value
                                  defined, but there is no upward limit. On the other hand, the NTR is
                                  limited to a maximum value of 20.47 pixels per millimeter (p/mm)
                                  plus/minus .20p/mm (520 pixels per inch (p/in) plus/minus 5p/in) for
                                  high resolution grayscale images, e.g., Type-4 records. The typical tenprint
                                  scanner scans at 600p/in. Therefore, we are unable to take advantage of
   290   291   292   293   294   295   296   297   298   299   300