GB/T 18284-2000 in English

《GB/T 18284-2000快速响应矩阵码》由TC28（全国信息技术标准化技术委员会）归口，主管部门为国家标准化管理委员会。
本标准规定了快速响应矩阵码（QR Code）符号的编码，符号结构和尺寸特征，纠错规则，参考译码算法，符号质量要求。本标准适用于自动识别和数据采集。

1 Scope

This standard specifies the encoding, symbol structure and size characteristics, error correction rules, reference decoding algorithm and symbol quality requirements of quick response matrix code (hereinafter referred to as“QR Code”).

This standard is applicable to automatic identification and data capture.

2 Reference standards

The following standards contain provisions which, through reference in this standard, constitute provisions of this standard. At the time of publication, all editions cited are valid.

All reference standards are subject to revision, and parties to agreements based on this standard are encouraged to investigate the possibility of applying the most recent editions of the following standards indicated below.

GB/T 1988-1998 Information technology - 7-bit Coded character set for information interchange (eqv ISO/IEC 646:1991)

GB 2312-1980 Code of Chinese graphic character set for information interchange - Primary set

GB/T 12905-2000 Bar coding terminology
GB 18030-2000 Information technology - Chinese ideograms coded character set for information interchange - Extension for the basic set
ISO/IEC 15424: 1999 Information technology - Automatic identification and data capture techniques - Data carrier/symbology identifiers
AIM International Technical Specification Extended Channel Interpretations: Part 1: Identification scheme and protocol (referred to as“AIM ECI specification”)

3 Definitions

For the purposes of this standard, the following definitions apply.

3.1 alignment pattern
fixed reference pattern in defined positions in a matrix symbology, which enables the decode software to resynchronise the coordinate mapping of the image modules in the event of moderate amounts of distortion of the image

3.2 character count indicator
bit sequence which defines the data string length in a mode

3.3 ECI designator
six-digit number identifying a specific ECI assignment

3.4 encoding region
region of the symbol not occupied by function patterns and available for encodation of data and error correction codewords

3.5 Extended Channel Interpretation (ECI)
protocol used in some symbologies that allows the output data stream to have interpretations different from that of the default character set

3.6 format information
function pattern containing information on the error correction level applied to the symbol and on the masking pattern used, essential to enable the remainder of the encoding region to be decoded

3.7 function pattern
specific pattern for symbol positioning and feature recognition in a symbol

3.8 mask pattern reference
three-bit identifier of the masking patterns applied to the symbol

3.9 masking
process of XORing the bit pattern in the encoding region with a masking pattern to provide a symbol with more evenly balanced numbers of dark and light modules and reduced occurrence of patterns which would interfere with fast processing of the image

3.10 mode
method of representing a defined character set as a bit string

3.11 mode indicator
four-bit identifier indicating in which mode the next data sequence is encoded

3.12 padding bit
0 bit, not representing data, used to fill empty positions of the final codeword after the Terminator in a data bit string

3.13 position detection pattern
one of three identical components of the Finder Pattern

3.14 remainder bit
0 bit, not representing data, used to fill empty positions of the symbol encoding region after the final symbol character, where the encoding region does not divide exactly into eight-bit symbol characters

3.15 remainder codeword
pad codeword used to fill empty codeword positions to complete the symbol if the total number of data and error correction codewords does not exactly fill its nominal capacity.The Remainder codewords come after the error correction codewords

3.16 segment
sequence of data encoded according to the rules of one ECI or encodation mode

3.17 separator
function pattern of all light modules, one module wide, separating the Position Detection Patterns from the rest of the symbol

3.18 terminator
bit pattern 0000 used to end the bit string representing data

3.19 timing pattern
alternating sequence of dark and light modules enabling module coordinates in the symbol to be determined

3.20 version
used for representing the series of symbol size. A particular version is determined in terms of its position in the sequence of permissible sizes. The permissible specification sizes of QR Code is 21 modules x 21 modules (Version 1) ~ 177 modules x 177 modules (Version 40). It may also indicate the error correction level applied to the symbol.

3.2 version information
function pattern containing information on the symbol version together with error correction bits for this data

4 Conventions

4.1 Mathematical operators

The mathematical operators used in this standard are defined as follows:

div is the integer division operator

mod is the integer remainder after division

Foreword
1 Scope
2 Reference standards
3 Definitions
4 Conventions
5 Symbol description
6 Data encoding and symbol representation
7 Structural append
8 Symbol printed
9 Symbol quality
10 Decoding procedures
11 QR code reference decoding algorithm
12 Data transmission
Annex A (Normative) Error correction generator polynomial
Annex B (Normative) Error correction decoding procedures
Annex C (Normative) Format information
Annex D (Normative) Version information
Annex E (Normative) Position of Alignment Pattern
Annex F (Normative) Symbol Indicator
Annex G (Informative) Examples of Encoding and Symbolic Representation
Annex H (Informative) Optimization of Bit Stream Length
Annex I (Informative) User Guidelines for Printing and Scanning QR Code Symbol
Annex J (Informative) Guidelines for Print Quality of Matrix Code
Annex K (Informative) Process Control Technology