ISO/IEC 29109-8:2011

INTERNATIONAL ISO/IEC
STANDARD 29109-8
First edition
2011-12-15
Information technology — Conformance
testing methodology for biometric data
interchange formats defined in
ISO/IEC 19794 —
Part 8:
Finger pattern skeletal data
Technologies de l'information — Méthodologie d'essai de conformité
pour les formats d'interéchange de données biométriques définis dans
l'ISO/CEI 19794 —
Partie 8: Données des structures du squelette de l'empreinte

Reference number
©
ISO/IEC 2011
©  ISO/IEC 2011
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ii © ISO/IEC 2011 – All rights reserved

Contents Page
Foreword . iv
Introduction . v
1 Scope . 1
2 Conformance . 1
3 Normative references . 2
4 Terms and definitions . 2
5 Symbols and abbreviated terms . 2
6 Conformance testing methodology . 2
6.1 Table of requirements in the base standard . 2
6.2 Table of test assertions . 13

© ISO/IEC 2011 – All rights reserved iii

Foreword
ISO (the International Organization for Standardization) and IEC (the International Electrotechnical
Commission) form the specialized system for worldwide standardization. National bodies that are members of
ISO or IEC participate in the development of International Standards through technical committees
established by the respective organization to deal with particular fields of technical activity. ISO and IEC
technical committees collaborate in fields of mutual interest. Other international organizations, governmental
and non-governmental, in liaison with ISO and IEC, also take part in the work. In the field of information
technology, ISO and IEC have established a joint technical committee, ISO/IEC JTC 1.
International Standards are drafted in accordance with the rules given in the ISO/IEC Directives, Part 2.
The main task of the joint technical committee is to prepare International Standards. Draft International
Standards adopted by the joint technical committee are circulated to national bodies for voting. Publication as
an International Standard requires approval by at least 75 % of the national bodies casting a vote.
Attention is drawn to the possibility that some of the elements of this document may be the subject of patent
rights. ISO and IEC shall not be held responsible for identifying any or all such patent rights.
ISO/IEC 29109-8 was prepared by Joint Technical Committee ISO/IEC JTC 1, Information technology,
Subcommittee SC 37, Biometrics.
ISO/IEC 29109 consists of the following parts, under the general title Information technology — Conformance
testing methodology for biometric data interchange formats defined in ISO/IEC 19794:
 Part 1: Generalized conformance testing methodology
 Part 2: Finger minutiae data
 Part 4: Finger image data
 Part 5: Face image data
 Part 6: Iris image data
 Part 7: Signature/sign time series data
 Part 8: Finger pattern skeletal data
 Part 9: Vascular image data
 Part 10: Hand geometry silhouette data
Finger pattern spectral data, signature/sign processed dynamic data, voice data and DNA data will form the
subjects of future parts.
iv © ISO/IEC 2011 – All rights reserved

Introduction
ISO/IEC 19794-8:2006 specifies a data record interchange format for exchange of finger pattern skeletal data
among systems within a Common Biometric Exchange Formats Framework (CBEFF) data structure. The data
stored in a finger pattern skeletal data record often contains the metadata storing the subject-specific, the
image-specific as well as the technology being used. This part of ISO/IEC 29109 establishes tests for
checking the correctness of the binary record.
The objective of ISO/IEC 19794-8:2006 cannot be completely achieved until biometric products can be tested
to determine whether they conform to those specifications. Conforming implementations are a necessary
prerequisite for achieving interoperability among implementations; therefore there is a need for a standardized
conformance testing methodology, test assertions, and test procedures as applicable to specific modalities
addressed by each part of ISO/IEC 19794. The test assertions will cover as much as practical of the
ISO/IEC 19794 requirements (covering the most critical features), so that the conformity results produced by
the test suites will reflect the real degree of conformity of the implementations to ISO/IEC 19794 Data
Interchange Format records. This is the motivation for the development of this conformance testing
methodology.
This part of ISO/IEC 29109 supports those applications that require use of finger pattern skeletal data
according to ISO/IEC 19794-8:2006. It defines a testing methodology to ensure conformance of a vendor’s
application or service to the base ISO/IEC 19794-8:2006 specification. Thus this part of ISO/IEC 29109 is
intended to:
 establish elements of the conformance testing methodology framework that are specific to the finger
pattern skeletal-based data record requirements of ISO/IEC 19794-8:2006 conformance testing,
 define requirements and guidelines for specifying conformance test suites and related test methods for
measuring conformity of products and services to the finger pattern skeletal data record requirements of
ISO/IEC 19794-8:2006, and
 define testing and reporting procedures to be followed before, during, and after conformance testing.
This part of ISO/IEC 29109 is applicable to the development and use of conformity test method specifications,
conformity test suites for ISO/IEC 19794-8:2006 records, and conformance testing programs for
ISO/IEC 19794-8:2006 conformant products. It is intended primarily for use by testing organizations, but may
be applied by developers and users of test method specifications and test method implementations.
The table of test assertions (Clause 6.2) specifies levels 1, 2 or 3 testing for the conformance requirements of
ISO/IEC 19794-8:2006.
Conformance testing of CBEFF requirements will be out of the scope of ISO/IEC 29109.

© ISO/IEC 2011 – All rights reserved v

INTERNATIONAL STANDARD ISO/IEC 29109-8:2011(E)

Information technology — Conformance testing methodology
for biometric data interchange formats defined in
ISO/IEC 19794 —
Part 8:
Finger pattern skeletal data
1 Scope
This part of ISO/IEC 29109 specifies elements of conformance testing methodology, test assertions, and test
procedures as applicable to ISO/IEC 19794-8:2006.
This part of ISO/IEC 29109 establishes
 test assertions of the structure of the finger pattern skeletal data format as specified in
ISO/IEC 19794-8:2006 (Type A Level 1 as defined in ISO/IEC 29109-1:2009),
 test asssertions of internal consistency by checking the types of values that may be contained within each
field (Type A Level 2 as defined in ISO/IEC 29109-1:2009).
This part of ISO/IEC 29109 does not establish
 test of conformance of CBEFF structures required by ISO/IEC 19794-8:2006,
 test of consistency with input biometric data record (Level 3),
 test of other characteristics of biometric products or other types of testing of biometric products
(e.g. acceptance, performance, robustness, security),
 test of conformance of systems that do not produce ISO/IEC 19794-8:2006 records.
2 Conformance
Biometric data interchange format conformance tests conform to this part of ISO/IEC 29109 if they satisfy all
of the normative requirements related to Clause 6. Specifically, they shall use the test methodology specified
in Clauses 6, 7 and 8 of ISO/IEC 29109-1:2009, and all Level 1 and Level 2 tests shall use the assertions
defined in Table 2 of Clause 6 in this International Standard.
Implementations of ISO/IEC 19794-8:2006 tested according to the methodology specified shall be able to
claim conformance only to those Biometric Data Record (BDR) requirements specified in
ISO/IEC 19794-8:2006 that are tested by the test methods established by this methodology.
Implementations of ISO/IEC 19794-8:2006 do not necessarily need to conform to all possible aspects of
ISO/IEC 19794-8:2006, but only to those ISO/IEC 19794-8:2006 requirements that are claimed to be
supported by the implementation in an ICS, filled out in accordance with Clause 8 of ISO/IEC 29109-1:2009
and Table 1 of this part of ISO/IEC 29109.
© ISO/IEC 2011 – All rights reserved 1

3 Normative references
The following referenced documents are indispensable for the application of this document. For dated
references, only the edition cited applies. For undated references, the latest edition of the referenced
document (including any amendments) applies.
ISO/IEC 19794-8:2006, Information technology — Biometric data interchange formats — Part 8: Finger
pattern skeletal data
ISO/IEC 29109-1:2009, Information technology — Conformance testing methodology for biometric data
interchange formats defined in ISO/IEC 19794 — Part 1: Generalized conformance testing methodology
4 Terms and definitions
For the purposes of this document, the terms and definitions given in ISO/IEC 29109-1 apply.
5 Symbols and abbreviated terms
For the purposes of this document, the symbols and abbreviated terms given in ISO/IEC 29109-1:2009 apply.
6 Conformance testing methodology
The testing methodology specified in Clauses 6, 7 and 8 of ISO/IEC 29109-1:2009 shall apply. The content of
the tables below is based on the conformance testing methodology outlined in ISO/IEC 29109-1:2009 and
shall only be used in the context of that testing methodology.
6.1 Table of requirements in the base standard
Under subformat applicability the columns labelled R, N and C indicate Finger pattern skeletal data record
format, Normal size finger pattern skeletal format and Compact size finger pattern skeletal format.
2 © ISO/IEC 2011 – All rights reserved

Table 1 — Requirements of the Base Standard (ISO/IEC 19794-8:2006)
Sub-format /
Reference in
Format Type
Requirement IUT Supported Test
Base Requirement Summary Level Status
Applicability
Identifier Support Range Result
Standard
R N C
Minutiae are points located at the
places in the fingerprint image
where friction ridges end or split
into two ridges. Each minutia
point has a “type” associated
R-1 6.1.1 with it. There are two major types 1 M Y Y Y
of minutia: a “ridge ending”
represented by the 2-bit value 01
and a “ridge bifurcation” or split
point represented by 2-bit value
10.
The coordinate system used to
express the position of the
minutiae points of a fingerprint
shall be a Cartesian coordinate
system.
For the skeletal pattern card
format, the resolution of the x
and y coordinates of the minutia
shall be in metric units.
The position of the minutia for a
R-2 6.1.2 ridge ending shall be defined as 3C O-1 Y Y Y N/A N/A
the coordinates of the skeleton
point with only one neighbour
pixel belonging to the skeleton.
The position of the minutia for a
ridge bifurcation shall be defined
as the point of forking of the
skeleton of the ridge.
The position of a virtual ending
shall be defined like the position
of a real ridge ending.
The direction of the lines starting
or ending at a point with more
than three arms (trifurcation,
etc.) shall be defined like the
R-3 6.1.3 3C O-1 Y Y Y N/A N/A
direction of a real ridge
ending.The direction of a virtual
ending shall be defined like the
direction of a real ridge ending.
To keep the encoding size small
a line shall start with a real
minutia (type 01 or 10) if
possible.
No assumption shall be made
about the order of the line
encodings in the record.
The skeleton shall be encoded
only for image areas where the
ridge lines are displayed with a
R-4 6.2.2 3C O-1 Y Y Y N/A N/A
sufficient quality.
The reconstructed ridge lines
shall describe the fingerprint
image in ridge position and
structure.
The reconstructed skeleton line
polygon element shall be inside
the area of the ridge it is
describing for most part of its
length.
© ISO/IEC 2011 – All rights reserved 3

Reference in Sub-format /
Requirement IUT Supported Test
Base Requirement Summary Level Status Format Type
Identifier Support Range Result
Standard Applicability
The reconstructed skeleton line
shall never be inside the area of
any other ridge but the one it is
describing.
The reconstructed skeleton line
shall preserve the topology of the
ridges.
In order to minimize integration
of digitalisation error, each
starting point must be computed
R-5 6.2.3 with relatively high accuracy, i.e. 3C O-1 Y Y Y N/A N/A
its resolution shall be at least
100 times finer than the spatial
reso
...