Executive summary

The INTERPOL Secretary General has agreed that there is a need for standardization of Automated Fingerprint Identification Systems (AFIS) to obtain a higher level of interoperability among systems that are manufactured by different companies. This document is intended to provide the reader with a convenient listing of Information Exchange Standards and Specifications related to the interchange of fingerprint data to be used in the acquisition of an AFIS as well as potential contract language to be used.

• Part 1 - AFIS Requirements is a matrix that relates requirements to the standards and specifications.
• Part 2, - Statement/ Scope of Work is the specific contract clauses to be used in any requests for proposal or tender issued by a procuring authority seeking to obtain an AFIS capable of exchanging fingerprint data with other organizations.

Part 1 - AFIS Requirements

DRAFT LANGUAGE FOR THE DEVELOPMENT OF SYSTEMS WHICH WILL INTERCHANGE FINGERPRINT INFORMATION.

In order to ensure the highest success in the exchange of fingerprint information it is necessary to standardize that information. This draft language is intended to assist in the writing of contracts to acquire AFIS. It is the intent that the first three pages, entitled "Information Exchange Standards and Specifications," are to be used to specify which standards and specifications shall be used to ensure system interoperability with other AFIS. The section entitled "Statement/Scope of Work" provides suggested language to be incorporated into the contract.

Therefore, all contracts which will exchange computerized fingerprint information shall include the following special provision/clause to incorporate the needed standards and specifications. Suggested contract language follows:

Information exchange standards and specifications

In order to ensure the utmost compatibility in the exchange of information between the AFIS being acquired and other systems, the following shall be required of all AFIS components. Requirements marked (M) are mandatory and those marked (D) are desirable.

The contractor may propose a newer standard that supercedes and incorporates those below throughout the period of performance of the contract. To include the newer standard the contractor shall (1) identify the existing standard; (2) identify the new standard proposed for use; and (3) provide a rationale for using the new items including the cost, schedule, performance, and supportability impacts; and receive written approval before commencing to incorporate the new standards. Even though the new standards are adopted, the old standards will be retained as the new standards build on the old.

Any conflict between the Standards or Specification shall be reconciled with the following order of precedence. (1) ANSI/NIST-CSL 1-1993, (2) AGN/66/RAP. No. 11, and Best Practice Recommendation for the Capture of Mugshots, INTERPOL Version.

(Note: The ANSI/NIST - ITL 1-1999 (Draft) standard is expected to be approved in early 2000. When the approval is finalized, this document may have to be revised accordingly.)

Part 2 - Statement/scope of work

The following language is provided to be used with a specific acquisition for one of the above type acquisitions. For example if the system to be acquired will process ten-prints and scene-of-crime marks then the language for those two sections below should be included in the solicitation and resultant contract. The suggested language is provided as a guide and may be modified as required. However, the specified requirements and/or specifications shall be included.

The purpose of the following language is to ensure that the ANSI/NIST standard is maintained throughout the AFIS development cycle and will be used as systems are updated and improved.

All AFIS

1.1 ANSI/NIST Structure (M)

To permit the exchange of fingerprint information data effectively across jurisdictional lines or between dissimilar systems made by different manufacturers, standards are needed to specify a common format for the data exchange. The American National Standards Institute has implemented ANSI/NIST-CSL 1-1993 which defines the context, format and units of measurement for the exchange of information that may be used in the fingerprint identification of a subject. The information consists of a variety of mandatory and optional items, including related recorded data, digitized fingerprint information, and compressed or uncompressed images. Information compiled and formatted in accordance with this standard can be recorded on machine-readable media and may be transmitted over data communications facilities in lieu of a fingerprint card. The system developed shall conform with the standard and shall be capable of transmitting and receiving Type - 1 records and shall specify which other record types are implemented for transmitting, or receiving, or both.

1.2 INTERPOL Implementation (M)

The INTERPOL General Secretariat has developed the INTERPOL Implementation INT - I data format which was recommended by the 66th INTERPOL General Assembly as the ICPO standard for the exchange of computerized fingerprint images between countries. The INT - I specifies that all calls for tenders should mention that an INTERPOL Standard exists and that the AFIS/AFR to be provided should meet that standard. The minimum standard for dots-per-inch (dpi) is 500, with a grayscale of 256 (minutiae are not to be transmitted). The two INTERPOL forms included in Report No. 18 shall be used as the basic documents. The existing INTERPOL X.400 communication system and any future developments of the system are to be used. Additional interfaces for connecting to other national systems are to be investigated.

1.3 Fingerprint Image Capture System (M)

Fingerprint Image Capture Systems should fulfill the quality requirements of Appendix F of FBI`s Electronic Fingerprint Transmission Specification (EFTS), dated January 29, 1999.This document provides the specifications which apply to fingerprint scanner systems and printers to ensure image quality. Electronic images must be of sufficient quality to allow for: (1) conclusive fingerprint comparisons (identification or non-identification decision); (2) fingerprint classification; (3) automatic feature detection; and (4) overall AFIS search reliability. The image quality requirements have associated test procedures which shall be used in acceptance testing to ensure compliance with the requirements, and in performance capability demonstrations as an indication of capability to perform.

1.4 Fingerprint Image Compression (M)

The WSQ Gray-scale Fingerprint Image Compression Specification is applicable to all continuous-tone gray-scale digital fingerprint images. The specification is to be used in conjunction with the ANSI/NSB-CLS 1-1993. The WSQ Gray-scale Fingerprint Image Compression Specification designates a class of encoders for converting source fingerprint image data to compressed image data. It also specifies a decoder process for converting compressed image data to reconstructed fingerprint image data, and coded representation for compressed image data. A best-practices requirement, derived from the above standard, is that fingerprint images shall be compressed only once.

Ten-Print processing

2.1 ANSI/NIST Type 4 Images (M)

The ANSI/NIST -CSL 1-1993 requires all Type 4 logical records shall contain high-resolution grayscale fingerprint image data that was scanned at no less than the minimum scanning resolution provided in the standard of 500 ppi. This minimum scanning resolution is to be used for the exchange of Type 4 high-resolution grayscale fingerprint images. The standard also provides for scanning at resolution greater than that provided in the standard by subsampling, scaling, and INTERPOLation. The data contained may be in compressed form. All Type 4 image files shall comply with the maximum compressions in the standard.

Palm-print processing

3.1 ANSI/NIST Type 7 or Type 15 Images (M)

The ANSI/NIST -CSL 1-1993 Type 7 (INTERPOL implementation), or ANSI/NIST- ITL 1-1999 type 15 palm print image records shall be used to exchange palm-print images. If compression is used, it shall use the same algorithm as Type 4 logical records.

3.2 Image Archive Backup in ANSI/NIST Format (M)

The ANSI/NIST -CSL 1-1993 Type 7 (INTERPOL implementation), or ANSI/NIST- ITL 1-1999 type 15 requirements shall apply to all Image Storage and Retrieval systems, to provide for future technical enhancements.

Mugshot processing

4.1 JPEG Compression (M)

All Type-10 records shall contain facial and/or scar, mark, and tattoo (SMT) image data and related ASCII information pertaining to the specific image contained in the record. For Type-10 records which are compressed they shall comply with the requirements of ANSI/NIST-ITL 1-1999 and specifically paragraph 17.1.11 which defines the compression algorithm.

4.2 Best Practice II Compliant Images (D)

The procedures and recommendations contained in the INTERPOL Best Practice Recommendation for the Capture of Mugshots contains a set of procedures and equipment specifications which will improve the interoperability between mugshot systems. These should be used to the maximum extent possible when developing an AFIS.

Scene-of-crime marks

5.1 ANSI/NIST Type 7 or 13 Images (M)

The ANSI/NIST -CSL 1-1993 Type 7 records (INTERPOL implementation) or the ANSI/NIST- ITL 1-1999 type 13 records shall contain latent images. The records shall be scanned at 500 ppi or more. If compression is used, it shall use the same algorithm as Type 4 logical records.

5.2 ANSI/NIST Type 7 or Type 13 Images (D)

It is desirable that AFIS acquisitions should have the capability to process records at more than 500 ppi as well as at 500 ppi. If this capability is included in the AFIS being acquired, it shall comply with all ANSI/NIST -CSL 1-1993 Type 7 requirements or Type 13 latent images.

5.3 Image Archive Backup in ANSI/NIST Type 7,Type 13 and Type 9 Format (M)

The ANSI/NIST -CSL 1-1993 Type 7, ANSI/NIST-ITL 1-1999 Type 13 and ANSI/NSB -CSL 1-1993 Type 9 (optional) requirements shall apply to all Image Storage and Retrieval systems.