ISO/IEC 15438:2015
(Main)Information technology — Automatic identification and data capture techniques — PDF417 bar code symbology specification
Information technology — Automatic identification and data capture techniques — PDF417 bar code symbology specification
ISO/IEC 15438:2015 specifies the requirements for the bar code symbology known as PDF417. It specifies PDF417 symbology characteristics, data character encodation, symbol formats, dimensions, error correction rules, reference decoding algorithm, and a number of application parameters.
Technologies de l'information — Techniques automatiques d'identification et de capture des données — Spécifications pour la symbologie de code à barres PDF417
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INTERNATIONAL ISO/IEC
STANDARD 15438
Third edition
2015-09-15
Information technology — Automatic
identification and data capture
techniques — PDF417 bar code
symbology specification
Technologies de l’information — Techniques automatiques
d’identification et de capture des données — Spécifications pour la
symbologie de code à barres PDF417
Reference number
ISO/IEC 15438:2015(E)
©
ISO/IEC 2015
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ISO/IEC 15438:2015(E)
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ISO/IEC 15438:2015(E)
Contents Page
Foreword .v
Introduction .vi
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Symbols, operations and abbreviated terms . 3
4.1 Symbols . 3
4.2 Mathematical operations . 4
4.3 Abbreviated terms . 4
5 Requirements . 4
5.1 Symbology characteristics . 4
5.1.1 Basic characteristics . 4
5.1.2 Summary of additional features . 5
5.2 Symbol structure . 6
5.2.1 PDF417 symbol parameters . 6
5.2.2 Row parameters . 6
5.2.3 Codeword sequence . 7
5.3 Basic encodation . 8
5.3.1 Symbol character structure . 8
5.3.2 Start and stop characters . 9
5.4 High level (data) encodation . 9
5.4.1 Function codewords .10
5.4.2 Text Compaction mode .12
5.4.3 Byte Compaction mode .17
5.4.4 Numeric Compaction mode .19
5.4.5 Advice to select the appropriate compaction mode .20
5.4.6 Treatment of PDF417 reserved codewords.20
5.5 Extended Channel Interpretation .21
5.5.1 Encoding the ECI assignment number .22
5.5.2 Pre-assigned and default Extended Channel Interpretations .22
5.5.3 Encoding ECI sequences within compaction modes .23
5.5.4 Post-decode protocol .25
5.6 Determining the codeword sequence .25
5.7 Error detection and correction .25
5.7.1 Error correction level .25
5.7.2 Error correction capacity .26
5.7.3 Defining the error correction codewords.26
5.8 Dimensions .27
5.8.1 Minimum width of a module (X) .27
5.8.2 Row height (Y) .27
5.8.3 Quiet zones .27
5.9 Defining the symbol format .27
5.9.1 Defining the aspect ratio of the module .27
5.9.2 Defining the symbol matrix of rows and columns .28
5.10 Generating the error correction codewords .29
5.11 Low level encodation .30
5.11.1 Clusters .31
5.11.2 Determining the symbol matrix .31
5.11.3 Determining the values of the left and right row indicators .32
5.11.4 Row encoding .32
5.12 Compact PDF417 .32
5.13 Macro PDF417 .32
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ISO/IEC 15438:2015(E)
5.13.1 Compaction modes and Macro PDF417 .33
5.13.2 ECIs and Macro PDF417 .33
5.14 User guidelines .33
5.14.1 Human readable interpretation .33
5.14.2 Autodiscrimination capability .33
5.14.3 User-defined application parameters .33
5.14.4 PDF417 symbol quality .34
5.15 Reference decode algorithm.34
5.16 Error detection and error correction procedure .34
5.17 Transmitted data .34
5.17.1 Transmitted data in the basic (default) interpretation .34
5.17.2 Transmission protocol for Extended Channel Interpretation (ECI) .35
5.17.3 Transmitted data for Macro PDF417 .36
5.17.4 Transmission of reserved codewords using the ECI protocol .36
5.17.5 Symbology identifier .36
5.17.6 Transmission using older protocols .36
Annex A (normative) Encoding/decoding table of PDF417 symbol character bar-
space sequences .37
Annex B (normative) The default character set for Byte Compaction mode .60
Annex C (normative) Byte Compaction mode encoding algorithm .61
Annex D (normative) Numeric Compaction mode encoding algorithm .63
Annex E (normative) User selection of error correction level .65
Annex F (normative) Tables of coefficients for calculating PDF417 error correction codewords .66
Annex G (normative) Compact PDF417 .70
Annex H (normative) Macro PDF417 .71
Annex I (normative) Testing PDF417 symbol quality .79
Annex J (normative) Reference decode algorithm for PDF417 .80
Annex K (normative) Error correction procedures .84
Annex L (normative) Symbology identifier .86
Annex M (normative) Transmission protocol for decoders conforming with original
PDF417 standards .87
Annex N (informative) Algorithm to minimise the number of codewords .93
Annex O (informative) Guidelines to determine the symbol matrix .95
Annex P (informative) Calculating the coefficients for generating the error correction
codewords – worked example .99
Annex Q (informative) Generating the error correction codewords - worked example .100
Annex R (informative) Division circuit procedure for generating error correction codewords .104
Annex S (informative) Additional guidelines for the use of PDF417 .106
Bibliography .108
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ISO/IEC 15438:2015(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.
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
The committee responsible for this document is ISO/IEC JTC 1, Information technology, Subcommittee
SC 31, Automatic identification and data capture techniques.
This third edition cancels and replaces the second edition (ISO/IEC 15438:2006), of which it constitutes
a minor revision.
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ISO/IEC 15438:2015(E)
Introduction
The technology of bar coding is based on the recognition of patterns of bars and spaces of defined
dimensions. There are various methods of encoding information in bar code form, known as
symbologies, and the rules defining the translation of characters into bars and space patterns and other
essential features are known as the symbology specification.
Manufacturers of bar code equipment and users of bar code technology require publicly available
standard symbology specifications to which they can refer when developing equipment and application
standards. It is the intent and understanding of ISO/IEC that the symbology presented in this
International Standard is entirely in the public domain and free of all user restrictions, licences and fees.
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INTERNATIONAL STANDARD ISO/IEC 15438:2015(E)
Information technology — Automatic identification and
data capture techniques — PDF417 bar code symbology
specification
1 Scope
This International Standard specifies the requirements for the bar code symbology known as PDF417.
It specifies PDF417 symbology characteristics, data character encodation, symbol formats, dimensions,
error correction rules, reference decoding algorithm, and a number of application parameters.
2 Normative references
The following documents, in whole or in part, are normatively referenced in this document and are
indispensable for its application. For dated references, only the edition cited applies. For undated
references, the latest edition of the referenced document (including any amendments) applies.
ISO/IEC 646, Information technology — ISO 7-bit coded character set for information interchange
ISO/IEC 15415, Information technology — Automatic identification and data capture techniques — Bar
code symbol print quality test specification — Two-dimensional symbols
ISO/IEC 15424, Information technology — Automatic identification and data capture techniques — Data
Carrier Identifiers (including Symbology Identifiers)
ISO/IEC 19762-1, Information technology — Automatic identification and data capture (AIDC)
techniques — Harmonized vocabulary — Part 1: General terms relating to AIDC
ISO/IEC 19762-2, Information technology — Automatic identification and data capture (AIDC)
techniques — Harmonized vocabulary — Part 2: Optically readable media (ORM)
ISO/IEC 24723, Information technology — Automatic identification and data capture techniques — GS1
Composite bar code symbology specification
3 Terms and definitions
For the purposes of this document, the terms and definitions given in ISO/IEC 19762-1, ISO/IEC 19762-2
and the following apply.
3.1
basic channel model
standard system for encoding and transmitting bar code data where data message bytes are output
from the decoder but no control information about the message is transmitted
Note 1 to entry: A decoder complying with this model operates in Basic Channel Mode.
3.2
bar-space sequence
sequence which represents the module widths of the elements of a symbol character
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ISO/IEC 15438:2015(E)
3.3
cluster
any of the three mutually exclusive subsets of PDF417 symbol characters
Note 1 to entry: The symbol characters in a given cluster conform with particular structural rules which are
used in decoding the symbology.
3.4
compaction mode
any of the three data compaction algorithms in PDF417 (Text, Numeric and Byte Compaction modes)
which are used to map 8-bit data bytes efficiently to PDF417 codewords
3.5
e-distance
distance from the leading edge of an element to the leading edge of the next similar element, or from
trailing edge to trailing edge
3.6
error correction codeword
encodes a value derived from the error correction codeword algorithm to enable decode errors to be
detected and, depending on the error correction level, to be corrected
3.7
Extended Channel Interpretation
ECI
procedure within some symbologies, including PDF417, to replace the default interpretation with
another interpretation in a reliable manner
Note 1 to entry: The interpretation intended prior to producing the symbol can be retrieved after decoding the
scanned symbol to recreate the data message in its original format.
3.8
Extended Channel Model
system for encoding and transmitting both data message bytes and control information about the
message, the control information being communicated using Extended Channel Interpretation (ECI)
escape sequences
Note 1 to entry: A decoder complying with this model operates in Extended Channel Mode.
3.9
function codeword
initiates a particular operation within a symbology
EXAMPLE To switch between data encoding sets, to invoke a compaction scheme, to program the reader, or
to invoke Extended Channel Interpretations.
3.10
Global Label Identifier
GLI
procedure in the PDF417 symbology which behaves in a similar manner to Extended Channel
Interpretation
Note 1 to entry: The GLI system was the PDF417-specific precursor to the symbology-independent ECI system.
3.11
Macro PDF417
procedure in the PDF417 symbology logically to distribute data from a computer file across a number of
related PDF417 symbols
Note 1 to entry: The procedure considerably extends the data capacity beyond that of a single symbol.
Note 2 to entry: This procedure is similar to the Structured Append feature in other symbologies.
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ISO/IEC 15438:2015(E)
3.12
Mode Latch codeword
used to switch from one mode to another mode, which stays in effect until another latch or shift
codeword is implicitly or explicitly brought into use, or until the end of the symbol is reached
3.13
Mode Shift codeword
used to switch from one mode to another for one codeword, after which encoding returns to the
original mode
3.14
Row Indicator codeword
PDF417 codeword adjacent to the start or stop character in a row, which encodes information about the
structure of the PDF417 symbol in terms of the row identification, total number of rows and columns,
and the error correction level
3.15
Symbol Length Descriptor
first codeword in a PDF417 symbol, which encodes the total number of data codewords in the symbol
4 Symbols, operations and abbreviated terms
4.1 Symbols
For the purposes of this International Standard, the following mathematical symbols apply. There are
some cases where the symbols below have been used in a different manner in an equation. This has been
done for consistency with a more general use of the notation and is always clearly defined in the text.
A symbol aspect ratio (height to width) of a PDF417 symbol
b element width in a symbol character
c number of columns in the symbol in the data region (excluding start, stop and row indicator code-
words)
d data codeword including all function codewords
E error correction codeword
e edge to similar edge dimension in a symbol character
F row number
f number of substitution errors
H height of symbol including quiet zone
K cluster number
k number of error correction codewords
L left row indicator
l number of erasures
m number of source data codewords prior to the addition of the Symbol Length Descriptor and any
pad codewords
n total number of data codewords including Symbol Length Descriptor and any pad codewords
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ISO/IEC 15438:2015(E)
p pitch or width of a symbol character
Q horizontal quiet zone
H
Q vertical quiet zone
V
R right row indicator
r number of rows in the symbol
s error correction level
W width of symbol including quiet zone
X X-dimension or module width
Y module height (also called row height)
4.2 Mathematical operations
For the purposes of this International Standard, the following mathematical operations apply.
div is the integer division operator, rounding down
INT is the integer value, i.e. where a number is rounded down to its whole number component,
ignoring its decimal fractions
mod is the positive integer remainder after division. If the remainder is negative, add the value of the
divisor to make it positive. For example, the remainder of –29 160 divided by 929 is –361 which
when added to 929 yields 568.
4.3 Abbreviated terms
For the purposes of this International Standard, the following abbreviated terms apply.
ECI Extended Channel Interpretation
GLI Global Label Identifier
5 Requirements
5.1 Symbology characteristics
5.1.1 Basic characteristics
PDF417 is a bar code symbology with the following basic characteristics.
a) Encodable character set:
1) Text Compaction mode (see 5.4.1.5) permits all printable ASCII characters to be encoded,
i.e. values 32 to 126 inclusive in accordance with ISO/IEC 646 (IRV), as well as selected
control characters;
2) Byte Compaction mode (see 5.4.3) permits all 256 possible 8-bit byte values to be encoded.
This includes all ASCII characters value 0 to 127 inclusive and provides for international
character set support;
3) Numeric Compaction mode (see 5.4.4) permits efficient encoding of numeric data strings;
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ISO/IEC 15438:2015(E)
4) Up to 811 800 different character sets or data interpretations;
5) Various function codewords for control purposes.
b) Symbol character structure: (n, k, m) characters of 17 modules (n), 4 bar and 4 space elements (k),
with the largest element 6 modules wide (m).
c) Maximum possible number of data characters per symbol (at error correction level 0): 925 data
codewords which can encode:
1) Text Compaction mode: 1 850 characters (at 2 data characters per codeword);
2) Byte Compaction mode: 1 108 characters (at 1,2 data characters per codeword);
3) Numeric Compaction mode: 2 710 characters (at 2,93 data characters per codeword).
At the minimum recommended error correction level, there is a maximum of 863 data codewords
which can encode:
4) Text Compaction mode: 1 726 characters (at 2 data characters per codeword);
5) Byte Compaction mode: 1 033 characters (at 1,2 data characters per codeword);
6) Numeric Compaction mode: 2 528 characters (at 2,93 data characters per codeword).
d) Symbol size:
1) Number of rows: 3 to 90;
2) Number of columns: 1 to 30;
3) Width in modules: 90X to 583X including quiet zones;
4) Maximum codeword capacity: 928 codewords;
5) Maximum data codeword capacity: 925 codewords.
Since the number of rows and the number of columns are selectable, the aspect ratio of a PDF417
symbol may be varied when printing to suit the spatial requirements of the application.
e) Selectable error correction: 2 to 512 codewords per symbol (see 5.7).
f) Non-data overhead:
1) Per row: 73 modules, including quiet zones;
2) Per symbol: a minim
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