1、 Collection of SANS standards in electronic format (PDF) 1. Copyright This standard is available to staff members of companies that have subscribed to the complete collection of SANS standards in accordance with a formal copyright agreement. This document may reside on a CENTRAL FILE SERVER or INTRA
2、NET SYSTEM only. Unless specific permission has been granted, this document MAY NOT be sent or given to staff members from other companies or organizations. Doing so would constitute a VIOLATION of SABS copyright rules. 2. Indemnity The South African Bureau of Standards accepts no liability for any
3、damage whatsoever than may result from the use of this material or the information contain therein, irrespective of the cause and quantum thereof. ISBN 978-0-626-21867-6 SANS 24778:2008Edition 1ISO/IEC 24778:2008Edition 1SOUTH AFRICAN NATIONAL STANDARD Information technology Automatic identification
4、 and data capture techniques Aztec Code bar code symbology specification Published by SABS Standards Division 1 Dr Lategan Road Groenkloof Private Bag X191 Pretoria 0001Tel: +27 12 428 7911 Fax: +27 12 344 1568 www.sabs.co.za SABS This national standard is the identical implementation of ISO/IEC 247
5、78:2008 and is adopted with the permission of the International Organization for Standardization and the International Electrotechnical Commission. SANS 24778:2008 Edition 1 ISO/IEC 24778:2008 Edition 1 Table of changes Change No. Date Scope National foreword This South African standard was approved
6、 by National Committee SABS SC 71K, Information technology Automatic identification and data capture techniques, in accordance with procedures of the SABS Standards Division, in compliance with annex 3 of the WTO/TBT agreement. This SANS document was published in September 2008. ISO/IEC 24778:2008(E
7、) ISO/IEC 2008 All rights reserved iiiContents Page Foreword. v Introduction . vi 1 Scope . 1 2 Normative references . 1 3 Terms, definitions, symbols and functions .1 3.1 Terms and definitions. 1 3.2 Symbols and functions 2 4 Symbology characteristics 3 4.1 Basic characteristics 3 4.2 Summary of ad
8、ditional features 4 5 Symbol description. 4 5.1 Symbol structure 5 5.2 Symbol character structure and sequence 6 5.3 Symbol size and capacity 7 6 General encodation procedures 8 7 Symbol structure 9 7.1 Fixed pattern structures. 9 7.2 Mode Message encoding and structure . 10 7.3 Data message encodin
9、g and structure.11 8 Structured Append . 14 9 Reader initialization symbols 14 10 Extended Channel Interpretation 15 10.1 Encoding ECIs in Aztec Code 15 10.2 Code sets and ECIs 15 10.3 ECIs and Structured Append. 15 10.4 Post-decode protocol. 15 11 User considerations . 16 11.1 User selection of enc
10、oded message. 16 11.2 User selection of minimum error correction level 16 11.3 User selection of Structured Append . 16 11.4 User selection of optional symbol formats 16 12 Dimensions 16 13 User guidelines . 17 13.1 Human readable interpretation 17 13.2 Autodiscrimination capability . 17 13.3 User-d
11、efined application parameters . 17 14 Reference decode algorithm . 17 14.1 Finding candidate symbols . 18 14.2 Processing the bullseye image . 18 14.3 Decoding the Core Symbol 18 14.4 Decoding the data message 19 14.5 Translating the datawords . 20 15 Symbol quality 20 15.1 Symbol quality parameters
12、 20 SANS 24778:2008This s tandard may only be used and printed by approved subscription and freemailing clients of the SABS .ISO/IEC 24778:2008(E) iv ISO/IEC 2008 All rights reserved15.2 Symbol print quality grading . 21 15.3 Process control measurements. 22 16 Transmitted data . 22 16.1 Basic inter
13、pretation 22 16.2 Protocol for FNC1 . 22 16.3 Protocol for ECIs. 22 16.4 Symbology identifier. 23 16.5 Transmitted data example 23 Annex A (normative) Aztec Runes 24 Annex B (normative) Error detection and correction . 26 Annex C (normative) Topological bullseye search algorithm . 29 Annex D (normat
14、ive) Linear crystal growing algorithm . 33 Annex E (normative) Fixed Pattern Damage grading . 34 Annex F (normative) Symbology identifiers 36 Annex G (informative) Aztec Code symbol encoding example . 37 Annex H (informative) Achieving minimum symbol size 41 Annex I (informative) Useful process cont
15、rol techniques 43 Bibliography . 45 SANS 24778:2008This s tandard may only be used and printed by approved subscription and freemailing clients of the SABS .ISO/IEC 24778:2008(E) ISO/IEC 2008 All rights reserved vForeword ISO (the International Organization for Standardization) and IEC (the Internat
16、ional 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 field
17、s 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 jo
18、int 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 committ
19、ee 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
20、not be held responsible for identifying any or all such patent rights. ISO/IEC 24778 was prepared by Joint Technical Committee ISO/IEC JTC 1, Information technology, Subcommittee SC 31, Automatic identification and data capture techniques. SANS 24778:2008This s tandard may only be used and printed b
21、y approved subscription and freemailing clients of the SABS .ISO/IEC 24778:2008(E) vi ISO/IEC 2008 All rights reservedIntroduction Aztec Code is a two-dimensional matrix symbology whose symbols are nominally square, made up of square modules on a square grid, with a square bullseye pattern at their
22、center. Aztec Code symbols can encode from small to large amounts of data with user-selected percentages of error correction. Manufacturers of bar code equipment and users of the technology require publicly available standard symbology specifications to which they can refer when developing equipment
23、 and application standards. The publication of standardised symbology specifications is designed to achieve this. SANS 24778:2008This s tandard may only be used and printed by approved subscription and freemailing clients of the SABS .INTERNATIONAL STANDARD ISO/IEC 24778:2008(E) ISO/IEC 2008 All rig
24、hts reserved 1Information technology Automatic identification and data capture techniques Aztec Code bar code symbology specification 1 Scope This International Standard defines the requirements for the symbology known as Aztec Code. It specifies the Aztec Code symbology characteristics including da
25、ta character encodation, rules for error control encoding, the graphical symbol structure, symbol dimensions and print quality requirements, a reference decoding algorithm, and user-selectable application parameters. 2 Normative references The following referenced documents are indispensable for the
26、 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 646:1991, Information technology ISO 7-bit coded character set for information interchange ISO/IEC 15
27、415:2004, Information technology Automatic identification and data capture techniques Bar code print quality test specification Two-dimensional symbols ISO/IEC 15424, Information technology Automatic identification and data capture techniques Data Carrier Identifiers (including Symbology Identifiers
28、) ISO/IEC 19762 (all parts), Information technology Automatic identification and data capture (AIDC) techniques Harmonized vocabulary AIM Inc. International Technical Specification: Extended Channel Interpretations Part 1, Identification Schemes and Protocols Part 2, Registration Procedure for Coded
29、 Character Sets and Other Data Formats Character Set Register 3 Terms, definitions, symbols and functions 3.1 Terms and definitions For the purposes of this document, the terms and definitions given in ISO/IEC 19762 and the following apply. 3.1.1 bullseye set of concentric square rings used as the f
30、inder pattern in Aztec Code SANS 24778:2008This s tandard may only be used and printed by approved subscription and freemailing clients of the SABS .ISO/IEC 24778:2008(E) 2 ISO/IEC 2008 All rights reserved3.1.2 checkword codeword which is included in a symbol for error correction and/or error detect
31、ion 3.1.3 dataword codeword which is part of the data message encoded in a symbol 3.1.4 domino 2-module sub-structure of the symbol character in Aztec Code which is the elemental entity used in graphical encoding of the symbol 3.1.5 Mode Message short fixed-length, error-corrected subsidiary message
32、 within an Aztec Code symbol which directly encodes the symbols size and data message length 3.2 Symbols and functions 3.2.1 Mathematical symbols For the purposes of this document, the following mathematical symbols apply. B the number of bits in each codeword Cbthe symbol capacity in number of bits
33、 Cwthe symbol capacity in number of codewords D the number of data (message) codewords in the symbol K the number of error correction codewords in the symbol, equal to Cw- D L the number of data layers (1 to 32) in the symbol, defining its size m the symbology identifier modifier value X the X-dimen
34、sion or nominal square grid spacing x a general variable used to express error correction polynomials (x,y) Cartesian coordinates within the module grid 3.2.2 Mathematical functions and operations For the purposes of this document, the following mathematical functions and operations apply. abs() is
35、the absolute value function div is the integer division operator max(a,b) is the greater of a and b mod is the remainder after integer division SANS 24778:2008This s tandard may only be used and printed by approved subscription and freemailing clients of the SABS .ISO/IEC 24778:2008(E) ISO/IEC 2008
36、All rights reserved 34 Symbology characteristics 4.1 Basic characteristics Aztec Code is a two dimensional matrix symbology with the following basic characteristics: a. Encodable character set: 1. All 8-bit values can be encoded. The default interpretation shall be: a. for values 0 to 127, in accord
37、ance with the U.S. national version of ISO/IEC 646; (NOTE: This version consists of the GO set of ISO/IEC 646 and the CO set of ISO/IEC 6429 with values 28 to 31 modified to FS, GS, RS and US respectively.) b. for values 128 - 255, in accordance with ISO/IEC 8859-1. This interpretation corresponds t
38、o ECI 000003. 2. Two non-data characters can be encoded, FNC1 for compatibility with some existing applications and ECI escape sequences for the standardized encoding of message interpretation information. b. Representation of data: A dark module is a binary one and a light module is a binary zero.
39、c. Symbol size: 1. The smallest Aztec Code symbol is 15 x 15 modules square, and the largest is 151 x 151. 2. No quiet zone is required outside the bounds of the symbol. d. Data capacity (at recommended error correction level): 1. The smallest Aztec Code symbol encodes up to 13 numeric or 12 alphabe
40、tic characters or 6 bytes of data. 2. The largest symbol encodes up to 3832 numeric or 3067 alphabetic characters or 1914 bytes of data. e. Selectable error correction: 1. User-selectable, from 5 % to 95 % of the data region, with a minimum of 3 codewords. 2. Recommended level is 23 % of symbol capa
41、city plus 3 codewords. f. Code type: Matrix g. Orientation independent: Yes SANS 24778:2008This s tandard may only be used and printed by approved subscription and freemailing clients of the SABS .ISO/IEC 24778:2008(E) 4 ISO/IEC 2008 All rights reserved4.2 Summary of additional features The followin
42、g summarizes additional features that are inherent or optional in Aztec Code: a. Reflectance Reversal (Inherent): Though Aztec Code symbols are shown and described in this specification always with the finders center dark and with dark modules encoding binary 1s throughout, symbols exhibiting the op
43、posite reflectance characteristics are easily autodiscriminated and decoded with the standard reader. b. Mirror Image (Inherent): Images which contain an Aztec Code symbol in mirror reversal, either because they are obtained using a reflected optical path, a reversed scan direction, or from behind t
44、hrough a clear substrate, are easily autodiscriminated and decoded with the standard reader. c. Extended Channel Interpretation (Optional): The ECI mechanism enables characters from various character sets (e.g. Arabic, Cyrillic, Greek, Hebrew) and other data interpretations or industry-specific requ
45、irements to be represented. d. Structured Append (Optional): Structured Append allows files of data to be represented logically and continually in up to 26 Aztec Code symbols. The symbols may be scanned in any sequence to enable the original data to be correctly reconstructed. e. Reader Initializati
46、on Symbols (Optional): A distinct format of Aztec Code symbol is available for use in barcode menus for reader initialization. The encoded message in these special symbols is never passed on to an application. f. Aztec “Runes” (Optional): a series of 256 small, machine-readable marks compatible with
47、 Aztec Code are available for special applications. See Annex A. 5 Symbol description Aztec Code symbols are nominally square, made up of square modules on a square grid, with a square bullseye pattern at their center. Figure 1 shows two representative Aztec Code symbols, a small 1-layer symbol on t
48、he left which encodes 12 digits with 47 % error correction and a larger 6-layer symbol on the right which encodes 168 text characters with 30 % error correction. Figure 1 Representative Aztec Code symbols These symbols illustrate the two basic formats of Aztec Code symbols: on the left is a “compact
49、” Aztec Code symbol, visually characterized by a 2-ring bullseye, useful for encoding shorter messages efficiently, while on the right is a “full-range” Aztec Code symbol, visually characterized by a 3-ring bullseye, which supports much larger symbols for longer data messages. Since encoders can autoselect and decoders autodiscriminate between the two formats, a seamless transition is achieved to cover the full spectrum of applications. SANS 24778:2008This s tandard may only be used and printed by approved subscription and f
