ISO/IEC 19794-8:2011/Amd 1:2014

INTERNATIONAL ISO/IEC
STANDARD 19794-8
Second edition
2011-12-15
AMENDMENT 1
2014-03-15
Corrected version
2014-04-01
Information technology — Biometric data
interchange formats —
Part 8:
Finger pattern skeletal data
AMENDMENT 1: Conformance testing
methodology
Technologies de l'information — Formats d'échange de données
biométriques —
Partie 8: Données des structures du squelette de l'empreinte
AMENDEMENT 1: Méthodologie d'essai de conformité

Reference number
ISO/IEC 19794-8:2011/Amd.1:2014(E)
©
ISO/IEC 2014
ISO/IEC 19794-8:2011/Amd.1:2014(E)

©  ISO/IEC 2014
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ii © ISO/IEC 2014 – All rights reserved

ISO/IEC 19794-8:2011/Amd.1:2014(E)
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.
Amendment 1 to ISO/IEC 19794-8:2011 was prepared by Joint Technical Committee ISO/IEC JTC 1,
Information technology, Subcommittee SC 37, Biometrics.
This corrected version of ISO/IEC 19794-8:2011/Amd.1:2014 corrects the Amendment number in the top right
corner on the cover page.
© ISO/IEC 2014 – All rights reserved iii

ISO/IEC 19794-8:2011/Amd.1:2014(E)

Information technology — Biometric data interchange
formats —
Part 8:
Finger pattern skeletal data
AMENDMENT 1: Conformance testing methodology
1. The following text is to be added to the "Introduction" clause of ISO/IEC 19794-8:
Annex A to document addresses the conformance testing to be used for interchange format defined in this
part of ISO/IEC 19794. This Annex A is distinct from the ISO/IEC 29109-8, which addressed conformance
testing only of the first, 2007, edition of the ISO/IEC 19794-8 standard.
2. The following text is to be added to the "Scope" clause of ISO/IEC 19794-8:
This part of ISO/IEC 19794 also specifies elements of conformance testing methodology, test assertions, and
test procedures as applicable to this part of ISO/IEC 19794. Specifically, it establishes
 test assertions of the structure of the finger pattern skeletal data format as specified in Clauses 7 and 8
of this part of ISO/IEC 19794 (Type A Level 1 as defined in ISO/IEC 19794-1:2011 AMD 1),
 test assertions 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 19794-1:2011 AMD 1),
 tests of semantic assertions (Type A Level 3 as defined in ISO/IEC 19794-1:2011 AMD 1).
The conformance testing methodology specified in this part of ISO/IEC 19794 does not establish
 tests of other characteristics of biometric products or other types of testing of biometric products (e.g.
acceptance, performance, robustness, security),
 tests of conformance of systems that do not produce data records conforming to the requirements of this
part of ISO/IEC 19794.
3. The following text is to be added to the "Conformance" clause of ISO/IEC 19794-8:
Biometric data interchange format conformance tests conform to this part of ISO/IEC 19794 if they satisfy all
of the normative requirements set forth in clauses 6, 7, and 8. Specifically, they shall use the test
methodology specified in ISO/IEC 19794-1:2011 AMD 1, and all Level 1, Level 2 and Level 3 tests shall use
the assertions defined in Table A.1 of Clause A.2 in this part of ISO/IEC 19794.
Implementations of this part of ISO/IEC 19794 tested according to the specified methodology shall be able to
claim conformance only to those biometric data record (BDB) requirements specified in this part of ISO/IEC
19794 that are tested by the test methods established by this methodology.
In consideration of the semantic specifics in different parts of 19794, all level 1, level 2, and level 3 tests shall
use the assertions defined in Table A.2 of clause A.3 of this part of 19794 in conformity with the concept and
rules set in 19794-1 Annex A.
© ISO/IEC 2014 – All rights reserved 1

ISO/IEC 19794-8:2011/Amd.1:2014(E)
4. Replace 3rd paragraph of Clause 6.2.3 "Constructing direction elements" with the following:
In order to minimize integration of digitalisation error, each starting point must be computed with relatively high
accuracy, i.e. its resolution shall be at least 100 times finer than the spatial resolution of the minutiae.
5. Replace the normative annex in ISO/IEC 19794-8:2011 with the following one:

2 © ISO/IEC 2014 – All rights reserved

ISO/IEC 19794-8:2011/Amd.1:2014(E)
Annex A
(normative)
Conformance Testing Methodology
A.1 Introduction
The testing methodology specified in ISO/IEC 19794-1:2011 AMD 1 shall apply. The content of the tables
below is based on the conformance testing methodology outlined in ISO/IEC 19794-1:2011 AMD 1 and shall
only be used in the context of that testing methodology.
A.2 Table of requirements in the base standard
The normative requirements of this part of ISO/IEC 19794 are listed in Table A.1. The supplier of the IUT
should explain which optional components of the standard are supported and the testing laboratory should
note the results of the test.
Table A.1 — Requirements of the Base Standard
Sub-format /
Format
Reference
Requirement IUT Supported Test
Type
in Base Level Status
Requirement Summary
Identifier Support Range Result
Applicability
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
Y Y Y
R-1 6.1.1 1 M N/A
has a “type” associated with it.
There are two major types 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 3C O-1 Y Y Y N/A N/A
ridge ending shall be defined as
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.
© ISO/IEC 2014 – All rights reserved 3

ISO/IEC 19794-8:2011/Amd.1:2014(E)
Sub-format /
Format
Reference
Requirement IUT Supported Test
Type
in Base Level Status
Requirement Summary
Identifier Support Range Result
Applicability
Standard
R N C
The direction of the lines starting or
ending at a point with more than
three arms (trifurcation, etc.) shall
R-3 6.1.3 be defined like the direction of a 3C O-1 Y Y Y N/A N/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 sufficient
quality.
The reconstructed ridge lines shall
R-4 6.2.2 3C O-1 Y Y Y N/A N/A
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.
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 with
R-5 6.2.3 3C O-1 Y Y Y N/A N/A
relatively high accuracy, i.e. its
resolution shall be at least 100
times finer than the spatial
resolution of the minutiae.
If the direction change of the
skeleton line cannot be described
by a direction element, the line
R-6 6.2.3 3C O-1 Y Y Y N/A N/A
encoding shall be interrupted by a
“virtual continuation” and a new
line encoding shall begin with the
same point without repeating the
minutia data.
It is not usefull to list a
R-7 6.3.2 neighourhood relation twice, any of 3A M Y Y Y
the other indices shall be different
i.e. Ai-1>Ai.
4 © ISO/IEC 2014 – All rights reserved

ISO/IEC 19794-8:2011/Amd.1:2014(E)
Sub-format /
Format
Reference
Requirement IUT Supported Test
Type
in Base Level Status
Requirement Summary
Identifier Support Range Result
Applicability
Standard
R N C
There shall be one and only one
record header for the finger pattern
7.3, Table
skeletal data record. The record
R-8 3A M Y N N
header will contain information
describing the identity and
characteristics of the device that
generated the data.
The finger pattern skeletal data
record shall begin with a format
identifier to be recorded in four
7.3.1,
R-9 1 M Y N N
bytes. For this part of ISO/IEC
Table 1
19794, it shall consist of the three
ASCII characters “FSK”, followed
by a zero byte as a NULL string
terminator.
The version number for the version
7.3.2,
R-10 of this part of ISO/IEC 19794 used 1 M Y N N
Table 1
in constructing the record shall be
placed in four bytes.
This version number shall consist
of three ASCII numerals followed
by a zero byte as a NULL string
terminator. The first and second
character will represent the major
7.3.2,
R-11 1 M Y N N
revision number and the third
Table 1
character will represent the minor
revision number. Upon approval of
this specification, the version
number shall be “020” (an ASCII
‘0’followed by an ASCII ‘2’ and an
ASCII ‘0’).
7.3.3,
R-12 1 M Y N N
The length of the entire BDIR shall
Table 1
be recorded in four bytes.
This count shall be the total length
7.3.3,
R-13 1 M Y N N
of the BDIR including the general
Table 1
record header and one or more
representation records.
The total number of representation
records contained in the BDIR shall
R-14 7.3.4 1 M Y N N
be recorded in two bytes. A
minimum of one representation is
required.
The one-byte certification flag shall
indicate whether each
Representation Header includes a
certification block. A value of
R-15 7.3.5 1 M Y N N
00HEX shall indicate that no
representation contains a
certification block. A value of
01HEX shall indicate that all
representations contain a certifica-
tion block.
© ISO/IEC 2014 – All rights reserved 5

ISO/IEC 19794-8:2011/Amd.1:2014(E)
Sub-format /
Format
Reference
Requirement IUT Supported Test
Type
in Base Level Status
Requirement Summary
Identifier Support Range Result
Applicability
Standard
R N C
A finger pattern skeletal
representation header shall start
each area of finger data providing
information for that finger. There
shall be one finger pattern skeletal
representation header for each
finger contained in the finger
R-16 7.4.1 pattern skeletal data record. The 1 M Y Y Y
finger pattern skeletal
representation header will occupy
at least 31 bytes as described
below. Note that it is permissible
for more than one single finger
record to represent the same
finger, with (presumably) different
data.
The representation-length field
R17 7.4.1.1 1 M Y Y Y
denotes the length in bytes of the
representation including the
representation header fields
The capture date and time field
shall indicate when the capture of
this representation started in
Coordinated Universal Time (UTC).
The capture date and time field
R-18 7.4.1.2 shall consist of 9 bytes. Its value 1 M Y Y Y
shall be encoded in the form given
in ISO/IEC 19794-1.This field shall
indicate the date and time the
representation was captured. This
field is not intended encode the
time the record was instantiated.
The capture device technology ID
shall be encoded in one byte. This
R-19 7.4.1.3 field shall indicate the class of 1 M Y Y Y
capture device technology used to
acquire the captured biometric
sample.
A value of 00HEX indicates
R-20 7.4.1.3 unknown or unspecified
1 M Y Y Y
technology. See Table 2 for the list
of possible values.
The capture device vendor
identifier shall be recorded in two
bytes. It shall identify the biometric
R-21 7.4.1.4 1 M Y Y Y
organisation that owns the product
that created the BDB and shall be
registered with the IBIA or other
approved registration authority.
A value of all zeros shall indicate
R-22 7.4.1.4
that the capture device vendor is 1 M Y Y Y
unreported.
6 © ISO/IEC 2014 – All rights reserved

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