ISO/IEC 19794-7:2014/Amd 1:2015

INTERNATIONAL ISO/IEC
STANDARD 19794-7
Second edition
2014-02-01
AMENDMENT 1
2015-07-15
Corrected version
2015‐12‐01
Information technology — Biometric
data interchange formats —
Part 7:
Signature/sign time series data
AMENDMENT 1: XML encoding
Technologies de l’information — Formats d’échange de données
biométriques —
Partie 7: Données de série chronologique de signature/signe
AMENDEMENT 1: Codage XML
Reference number
ISO/IEC 19794-7:2014/Amd.1:2015(E)
©
ISO/IEC 2015
ISO/IEC 19794-7:2014/Amd.1:2015(E)

© ISO/IEC 2015, Published in Switzerland
All rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilized otherwise in any form
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ii © ISO/IEC 2015 – All rights reserved

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.
The procedures used to develop this document and those intended for its further maintenance are described
in the ISO/IEC Directives, Part 1. In particular the different approval criteria needed for the different types of
document should be noted. This document was drafted in accordance with the editorial rules of the
ISO/IEC Directives, Part 2 (see www.iso.org/directives).
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. Details of any
patent rights identified during the development of the document will be in the Introduction and/or on the ISO
list of patent declarations received (see www.iso.org/patents).
Any trade name used in this document is information given for the convenience of users and does not
constitute an endorsement.
For an explanation on the meaning of ISO specific terms and expressions related to conformity assessment,
as well as information about ISO's adherence to the WTO principles in the Technical Barriers to Trade (TBT)
see the following URL: Foreword - Supplementary information
Amendment 1 to ISO/IEC 19794-7:2014 was prepared by Joint Technical Committee ISO/IEC JTC 1,
Information technology, Subcommittee SC 37, Biometrics.
The corrected version of ISO/IEC 19794-7:2014/Amd 1:2015 incorporates the following corrections.
"Table A.2.2" in AMD 1-8 has been corrected to read "Table A.3".
"Table A.2.3" in AMD 1-9 has been corrected to read "Table A.4".
The sentence in AMD1-9 has been replaced with: "Rename clause "A.2.3 Conformance test assertions for
compression format (binary format)" and ”Table A.2.3 – Conformance test assertions for compression format
(binary format)” in “Annex A”.
"Table A.2.4" in AMD 1-10 has been corrected to read "Table A.5".
© ISO/IEC 2015 – All rights reserved iii

AMENDMENT ISO/IEC 19794-7:2014/Amd 1:2015(E)N/A
Information technology — Biometric data interchange
formats — Part 7: Signature/sign time series data
AMENDMENT 1: XML encoding
AMD1-1: Insert the following text as introduction to AMENDMENT 1: XML encoding
Additionally, this part of the ISO/IEC standard supports both binary and XML encoding, to
support a spectrum of user requirement. With XML, this part will meet the requirements
modern IT architectures. With binary encoding this part will also be able to be used in
bandwidth or storage constrained environments. Annex E specifies the schema that XML
encoded signature/sign time series data record must conform to, and Annex F provides an
example of a valid XML encoded signature/sign time series data record.
AMD1-2: Replace in clause “1 Scope” "three data formats" with "three binary data formats"
Replace in the first listing the second bullet point “three data formats” with “three binary data
formats”.
AMD1-3: Add in clause “1 Scope” in the first listing a fourth bullet point"
Add in clause “1 Scope” as fourth bullet point of the first listing following:
- an XML schema definition
AMD1-4: Insert the following text into clause “2 Conformance” as second paragraph
An XML document conforms to this part of ISO/IEC 19794 if it satisfies the format
requirements with respect to its structure, relations among its fields, and relations between
its fields and the underlying input that are specified within Annex E of this part of ISO/IEC
19794.
AMD1-5: Insert the following text in the appropriate alphabetical order of Clause , Normative
reference:
- http://www.w3.org/XML/Schema
© ISO/IEC 2015 – All rights reserved 1

AMD1-6: Replace ”Table A.1 – Table of requirements” in “Annex A”
Table A.1– Table of requirements
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R-1 6.1 The coordinate system used to express the 3B M Y Y Y Y N/A
pen position shall be a three-dimensional
Cartesian coordinate system.
R-2 6.1 The x axis shall be the horizontal axis of the 3B M Y Y Y Y N/A
writing plane, with x coordinates increasing to
the right.
R-3 6.1 The y axis shall be the vertical axis of the 3B M Y Y Y Y N/A
writing plane, with y coordinates increasing
upwards.
R-4 8.2.2 The format ID shall be recorded in four bytes. 1 M Y N N N
The format ID shall consist of three characters
"SDI" followed by Null (00 ) as a string
Hex
terminator.
R-5 10.2 The format ID shall be recorded in four bytes. 1 M N N Y N
The format ID shall consist of three characters
"SCD" followed by Null (00 ) as a string
Hex
terminator.
R-6 8.2.3, The number for the version of this part of 1 M Y N Y N
10.2 ISO/IEC 19794 shall be placed in four bytes.
The version number shall consist of the three
characters “020” followed by Null as a string
terminator (3032 3000 ).
Hex
R-7 8.2.4, The length (in bytes) of the entire BDIR shall 2 M Y N Y N
10.2 be recorded in four bytes. This count shall be
the total length of the BDIR including the
general record header and one or more rep-
resentation records.
R-8 8.2.5, The total number of representation records 2 M Y N Y N
10.2 contained in the BDIR shall be recorded in two
bytes. A minimum of one representation is
required.
R-9 8.2.6, The one-byte certification flag shall indicate 2 M Y N Y N
10.2 whether each Representation Header includes
a certification record. A value of 00 shall
Hex
indicate that no representation contains a
certification record. A value of 01 shall indi-
Hex
cate that all representations contain a certifi-
cation record.
R-10 8.3.1, A Representation Header shall precede each 1 M Y N Y N
10.3.1 representation providing information for that
representation. There shall be one header for
each representation contained in the BDIR.
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R-11 8.3.2.2 The total number of bytes in the entire repre-2 M Y N Y N
, sentation, including the Representation
10.3.2. Header, shall be recorded in four bytes.
R-12 8.3.2.3 The Gregorian calendar year of the capture 1 M Y N Y N
, date and time field shall be encoded in the
10.3.2. form given in ISO/IEC 19794-1:2011.
R-13 8.3.2.3 The month of the capture date and time field 1 M Y N Y N
, shall be encoded in the form given in ISO/IEC
10.3.2. 19794-1:2011.
R-14 8.3.2.3 The day of the capture date and time field 1 M Y N Y N
, shall be encoded in the form given in ISO/IEC
10.3.2. 19794-1:2011.
R-15 8.3.2.3 The hour of the capture date and time field 1 M Y N Y N
, shall be encoded in the form given in ISO/IEC
10.3.2. 19794-1:2011.
R-16 8.3.2.3 The minute of the capture date and time field 1 M Y N Y N
, shall be encoded in the form given in ISO/IEC
10.3.2. 19794-1:2011.
R-17 8.3.2.3 The second of the capture date and time field 1 M Y N Y N
, shall be encoded in the form given in ISO/IEC
10.3.2. 19794-1:2011.
R-18 8.3.2.3 The millisecond of the capture date and time 1 M Y N Y N
, field shall be encoded in the form given in
10.3.2. ISO/IEC 19794-1:2011.
R-19 8.3.2.3 The capture date and time field shall indicate 3C M Y N Y N
, when the capture of this representation started
10.3.2. in Coordinated Universal Time (UTC).
R-20 8.3.2.4 The capture device technology ID shall be en-1 M Y N Y N
, coded in one byte. A value of 00 indicates
Hex
10.3.2. unknown or unspecified technology. See
1 Table 3 for the list of possible values.
R-21 8.3.2.4 The capture device technology ID shall indi-3C M Y N Y N
, cate the class of capture device technology
10.3.2. used to acquire the captured biometric
1 sample.
R-22 8.3.2.5 The capture device vendor ID shall be 1 M Y N Y N
, encoded in two bytes. A value of all zeros
10.3.2. shall indicate that the capture device vendor is
1 unreported.
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R-23 8.3.2.5 The capture device vendor ID shall be regis-3C M Y N Y N
, tered by IBIA or other approved registration
10.3.2. authority.
R-24 8.3.2.6 The capture device type ID shall be encoded 1 M Y N Y N
, in two bytes. A value of all zeros shall indicate
10.3.2. that the capture device type is unreported.
R-25 8.3.2.6 The capture device type ID shall be assigned 3C M Y N Y N
, by the registered product owner or other
10.3.2. approved registration authority.
R-26 8.3.2.7 A quality record shall begin with a length field. 2 M Y N Y N
, The length field shall consist of one byte. It
10.3.2. shall represent the number of quality blocks as
1 an unsigned integer.
R-27 8.3.2.7 A quality score shall be encoded in one byte 1 M Y N Y N
, as an unsigned integer. Allowed values are
10.3.2.
– 0 to 100 with higher values indicating
better quality,
– 255, i.e. ff , for indicating that an attempt
Hex
to calculate a quality score failed.
R-28 8.3.2.7 The quality algorithm vendor ID shall be 1 M Y N Y N
, encoded in two bytes. A value of all zeros
10.3.2. shall indicate that the quality algorithm vendor
1 is unreported.
R-29 8.3.2.7 The quality algorithm vendor ID shall be 3C M Y N Y N
, registered by IBIA or other approved registra-
10.3.2. tion authority.
R-30 8.3.2.7 The quality algorithm ID shall be encoded in 1 M Y N Y N
, two bytes. A value of all zeros shall indicate
10.3.2. that the quality algorithm is unreported.
R-31 8.3.2.7 The quality algorithm ID shall be registered by 3C M Y N Y N
, IBIA or other approved registration authority.
10.3.2.
R-32 8.3.2.8 The channel inclusion field shall consist of two 1 M Y N Y N
.1, bytes.
10.3.2.
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R-33 8.3.2.8 A bit value of 1 in the channel inclusion field 2 M Y N Y N
.1, shall encode the presence of the
10.3.2. corresponding channel; a bit value of 0 shall
1 encode the absence of the corresponding
channel.
The channel inclusion field shall be followed
by a sequence of channel descriptions for the
channels indicated as present in the channel
inclusion field. The order of the channel
descriptions is determined by the order of indi-
cated inclusion within the channel inclusion
field starting with the X channel. The channel
descriptions are mandatory for all channels
present in the signature/sign time series data
record.
R-34 8.3.2.8 Each bit of the channel inclusion field shall 3A M Y N Y N
.1, correspond to a channel as shown in Table 4.
10.3.2.
R-35 8.3.2.8 Each channel description shall begin with a 1 M Y N Y N
.2, preamble. Each channel description preamble
10.3.2. shall consist of one byte.
The unused trailing bit of the preamble shall
have value 0 and is reserved by ISO/IEC JTC
1/SC 37 for future use.
R-36 8.3.2.8 Each of the bits 4 through 8 of a channel 2 M Y N Y N
.2, description preamble shall correspond to a
10.3.2. channel attribute as shown in Table 5. A bit
1 value of 1 shall encode the presence of the
corresponding channel attribute; a bit value of
0 shall encode the absence of the correspond-
ing channel attribute. If any of the bits 4
through 8 of a channel description preamble
are set to 1, the preamble shall be followed by
a sequence of channel attributes in the same
order as indicated in the preamble starting
with the scaling value.
R-37 8.3.2.8 A value of 1 for bit 3 of a channel description 2 M Y N Y N
.2, preamble shall indicate that the value of this
10.3.2. channel is constant. If bit 3 of a channel
1 description preamble is set to 1, then this
channel shall be absent in the representation
body even though the representation header
indicates the presence of the channel.
R-38 8.3.2.8 If the channel description of a channel whose 3A M Y N Y N
.2, value is constant contains a scaling value,
10.3.2. then the constant value of this channel shall
1 be 1 divided by the scaling value.
R-39 8.3.2.8 A value of 1 for bit 2 of a channel description 2 M Y N Y N
.2, preamble shall indicate that the linear
10.3.2. component of the regression line for this chan-
1 nel has been removed from this channel.
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R-40 8.3.2.8 If present, scaling values shall consist of two 1 O Y N Y N
.3, bytes. The five most significant bits of the first
10.3.2. byte shall constitute the exponent field E, and
1 the remaining 11 bits shall constitute the
fraction field F.
The scaling value s is calculated by
 
F
E16
s1  2
.
 
 2 
R-41 8.3.2.8 If present, the minimum and maximum 1 O Y N Y N
.4, possible channel values shall be encoded in
10.3.2. two bytes.
R-42 8.3.2.8 If present, the minimum and maximum 3A O Y N Y N
.4, possible channel values shall indicate the
10.3.2. scaled range of values that the deployed
1 capture device may deliver for the cor-
responding channel.
For the minimum and maximum possible
channel values of the Z, T, DT, F, A, E, and R
channels, integer values in the range from 0 to
65 535 are allowed. These values shall be
encoded in two bytes as unsigned integers.
For the minimum and maximum possible
channel values of the X, Y, VX, VY, AX, AY,
TX, and TY channels, integer values in the
range from –32 768 to 32 767 are allowed.
These values shall be encoded in two bytes
as unsigned integers after adding 32 768 to
each value. Hence, for non-negative numbers,
bit 8 of the most significant byte has the value
1; for negative numbers, bit 8 of the most sig-
nificant byte has the value 0. For decoding
these values, 32 768 is to be subtracted from
each recorded value.
R-43 8.3.2.8 If a scaling value is present, the minimum and 3A O Y N Y N
.3, maximum possible channel values are to be
10.3.2. divided by the corresponding scaling value to
1 obtain their actual values.
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R-44 8.3.2.8 If present, the average of the channel values 2 O Y N Y N
.5,
, rounded to the
shall be the arithmetic mean c
10.3.2.
nearest integer, of all values c ( 1 i N
i
where N is the number of sample points) for
the corresponding channel within a signature/
sign time series data record:
N
c ∑c .
i
N
i1
For the averages of the Z, T, DT, F, A, E, and
R channels, integer values in the range from 0
to 65 535 are allowed. These values shall be
encoded in two bytes as unsigned integers.
For the averages of the X, Y, VX, VY, AX, AY,
TX, and TY channels, integer values in the
range from -32 768 to 32 767 are allowed.
These values shall be encoded in two bytes
as unsigned integers after adding 32 768 to
each value. Hence, for non-negative numbers,
bit 8 of the most significant byte has the value
1; for negative numbers, bit 8 of the most sig-
nificant byte has the value 0. For decoding
these values, 32 768 is to be subtracted from
each recorded value.
R-45 8.3.2.8 If a scaling value is present, the average 3A O Y N Y N
.3, channel values are to be divided by the cor-
10.3.2. responding scaling value to obtain their actual
1 values.
R-46 8.3.2.8 If present, the standard deviation of the 2 O Y N Y N
.5, channel values shall be the empirical standard
10.3.2.
deviation  , rounded to the nearest integer,
c
of all values c ( 1 i N ) for the cor-
i
responding channel within a signature/sign
time series data record:
N
  ∑(c - c) .
c i
N
i1
For the standard deviations of all channels,
integer values in the range from 0 to 65 535
are allowed. These values shall be encoded in
two bytes as unsigned integers.
R-47 8.3.2.8 If a scaling value is present, the standard 3A O Y N Y N
.3, deviation values are to be divided by the cor-
10.3.2. responding scaling value to obtain their actual
1 values.
R-48 8.3.2.9 The length field shall consist of three bytes. 1 M Y N Y N
,
10.3.2.
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R-49 8.3.2.9 The length field shall indicate the number of 2 M Y N Y N
, sample points as an unsigned integer.
10.3.2.
R-50 10.3.2. The compression algorithm ID shall be 1 M N N Y N
2 encoded in one byte. See Table 9 for the list
of possible values.
R-51 10.3.2. The compressed-data length field shall consist 1 M N N Y N
3 of four bytes.
R-52 10.3.2. The compressed-data length field shall denote 2 M N N Y N
3 the total number of bytes in the compressed
data.
R-53 8.3.3.2 Each sample point field shall consist of a 2 M Y N N N
sequence of selected channel values as
indicated by the channel inclusion field. The
order of the channel values is determined by
the order of indicated inclusion within the
channel inclusion field.
R-54 8.3.3.2 For the Z, T, DT, F, Az, El, and R channels, 2 M Y N N N
integer values in the range from 0 to 65 535
are allowed. These values shall be encoded in
two bytes as unsigned integers.
R-55 8.3.3.2 For the X, Y, VX, VY, AX, AY, TX, and TY 2 M Y N N N
channels, integer values in the range from –
32 768 to 32 767 are allowed. These values
shall be encoded in two bytes as unsigned
integers, after adding 32 768 to each value.
Hence, for non-negative numbers, bit 8 of the
most significant byte has the value 1; for
negative numbers, bit 8 of the most significant
byte has the value 0. For decoding these
values, 32 768 is to be subtracted from each
recorded value.
R-56 8.3.3.2 For the S channel, the values 0 and 1 are 2 M Y N N N
allowed. These values shall be encoded in
one byte as unsigned integers.
R-57 8.3.2.8 If a scaling value is present, the channel 3A O Y N Y N
.3, values in the representation body are to be
10.3.2. divided by the corresponding scaling value to
1 obtain their actual values.
R-58 10.3.3. The data to be compressed shall consist of a 2 M N N Y N
1 sequence of difference channels, one for each
channel that is indicated as present by the
channel inclusion field in the representation
header. The sequence of difference channels
shall be compressed using the compression
algorithm indicated by the compression algo-
rithm ID field in the representation header.
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R-59 10.3.3. Every difference channel shall start with the 3A M N N Y N
2 initial value c of the channel, encoded as
defined in clause 8.3.3.2. This is followed by a
sequence of differences between values at
d  c  c
consecutive sample points
i i1 i
(1 i N 1). Each d shall be encoded in two
i
by
...