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MPR publication—Part 2:Specification of MPR code symbols

Basic Information

Standard ID: GB/T 27937.2-2011

Standard Name:MPR publication—Part 2:Specification of MPR code symbols

Chinese Name: MPR出版物 第2部分:MPR码符号规范

Standard category:National Standard (GB)

state:in force

Date of Release2011-12-30

Date of Implementation:2012-03-01

standard classification number

Standard ICS number:General, Terminology, Standardization, Documentation>>Informatics, Publishing>>01.140.40

Standard Classification Number:General>>Economy, Culture>>A14 Library, Archives, Documentation and Information Work

associated standards

Publication information

publishing house:China Standards Press

Publication date:2012-03-01

other information

Release date:2011-12-30

drafter:Lü Yingfeng, Cai Xun, Wei Yushan, Liu Yingli, Wang Wenfeng, Liu Yuzhu, Zhou Zhixu

Drafting unit:Shenzhen Tianlang Times Technology Co., Ltd., China Press and Publication Research Institute, China Electronics Technology Standardization Institute

Focal point unit:General Administration of Press and Publication of the People's Republic of China

Proposing unit:General Administration of Press and Publication of the People's Republic of China

Publishing department:General Administration of Quality Supervision, Inspection and Quarantine of the People's Republic of China Standardization Administration of China

competent authority:General Administration of Press and Publication of the People's Republic of China

Introduction to standards:

GB/T 27937.2-2011 MPR Publication Part 2: MPR Code Symbol Specification GB/T27937.2-2011 |tt||Standard compression package decompression password: www.bzxz.net
This part of GB/T27937 specifies the structure, data encoding, symbol generation method and symbol quality level of MPR code symbols used in MPR publications. This part is applicable to the generation, recognition and quality level determination of MPR code symbols.
GB/T27937 "MPR Publication" includes the following parts:
———Part 1: MPR code encoding rules;
———Part 2: MPR code symbol specifications;
———Part 3: General production specifications;
———Part 4: MPR code symbol printing quality requirements and inspection methods;
———Part 5: Basic management specifications.
This part is Part 2 of GB/T27937.
This part was drafted in accordance with the rules given in GB/T1.1-2009. ||tt ||
This part was proposed and managed by the General Administration of Press and Publication of the People's Republic of China.
The main drafting units of this part are Shenzhen Tianlang Times Technology Co., Ltd., China Press and Publication Research Institute, and China Electronics Technology Standardization Institute.
The main drafters of this part are: Lv Yingfeng, Cai Xun, Wei Yushan, Liu Yingli, Wang Wenfeng, Liu Yuzhu, Zhou Zhixu.
The following documents are indispensable for the application of this document. For any dated referenced document, only the dated version applies to this document. For any undated referenced document, the latest version (including all amendments) applies to this document.
GB/T1988—1998 Information technology Seven-bit coded character set for information interchange (eqvISO/IEC646:1991)
GB/T12905—2000 Bar code terminology
GB/T27937.1 MPR publication Part 1: MPR code encoding rules
Foreword I
Introduction II
1 Scope 1
2 Normative references 1
3 Terms and definitions 1
4 Conventions 2
5 Symbol structure 2
6 Data coding and symbol generation 5
7 Quality of MPR code symbols 5
Appendix A (Informative) Reference decoding method 8
References 10

Some standard content:

ICS 01. 140. 40
National Standard of the People's Republic of China
GB/T 27937.2--2011
MPR publication
Part 2: Specification of MPR code symbols
MPR publication-Part 2 :Specification of MPR code symbols Issued on 2011-12-30
General Administration of Quality Supervision, Inspection and Quarantine of the People's Republic of China Administration of Standardization of the People's Republic of China
Implementation on 2012-03-01
GB/T 27937. 2-2011
Normative references
3 Terms and definitions
Symbol structure
Data coding and symbol generation
Quality of MPR code symbols
Appendix A (Informative Appendix)
References
Reference decoding method
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GB/T27937MPR Publication" includes the following parts:-Part 1: MPR code encoding rules:
-Part 2 MPR code symbol specifications:
Part 3, General production specifications;
Part 4: MPR code symbol printing quantity requirements and inspection methods Part 5: Basic management specifications.
This part is Part 2 of GB/T27937. This part was drafted in accordance with the rules given in GB/T 1, I-2009. This part was proposed and issued by the General Administration of Press and Publication of the People's Republic of China. GB/T 27937,2--2011
The main drafting units of this part: Shenzhen Tianlang Times Technology Co., Ltd., China Press and Publication Research Institute. China Electronic Technology Standardization Institute.
The main drafters of this part are Wu Yingfeng, Cai Xun, Wei Yushan, Liu Yingli, Wang Wenfeng, Liu Yuzhu and Zhou Zhixu. TTTKANRYKAA
GB/T 27937. 2—2011
MPR (Multimedia Print Reader) publication is a kind of publication that integrates and accurately associates various publishing carriers and forms of expression based on unique association comprehensive codes and uses specific matrix MPR two-dimensional codes as machine-readable symbols to form a multimedia composite digital publishing form based on paper printing carriers. MPR publications are composed of three basic elements: MPR books and newspapers, MPR digital media files, and MPR codes that accurately associate the two.
MPR books and newspapers are the main body of MPR publications and the only fixed material carrier form in MPR publications. It prints pictures, texts and MPR code symbols on pages in a conventional printing method. Due to the unique design of MPR code symbols, they are almost imperceptible to the visual senses and can only be optically read by reading equipment, so there is no obvious difference between the surface of MPR books and newspapers and ordinary books and newspapers. MPR digital media files are a collection of digital media content such as sound, graphics, and images that have been processed in association with the content of MPR books and newspapers. The file is usually published on the Internet. Readers can download the file and play the sound, graphics, images, and other content associated with the MPR code symbols in the digital media file through related devices when reading MPR books and newspapers. MPR code consists of a set of decimal 16-bit numbers - a code that establishes an association relationship between two or more different forms of content. It is carried in a binary encoding method by a specific machine-readable two-dimensional code symbol (generated according to the specifications of Part 2 of GB/T27937), and can be printed in a nearly invisible manner to fix it in the relevant position on the page of MPR books and newspapers. MPR code is a two-segment coding structure, divided into a preamble and a postamble. Its preamble is the overall association code segment, which determines a unique association relationship between various sets of content in different forms of expression in a MIPR publication. The post-code is a content-related code segment, which is set in accordance with the content of the MPR publication for the purpose of presenting different forms of expression. The capacity of the MPR code can ensure the long-term unique coding requirements of MPR publications published worldwide. The pre-code of the MPR code is allocated by the MPR code management agency, and the post-code is set by the publication producer (publisher) according to the relevant rules specified in this standard according to the content association needs. The issuing agency of this document calls attention to the fact that when declaring compliance with this document, it may involve the use of patents related to symbol graphics, code word layout and decoding algorithms in Chapter 5 and Chapter 6. The issuing agency of this document has no position on the authenticity, validity and scope of the patent. The patent holder has guaranteed to the issuing agency of this document that any publisher registered with relevant institutions in the People's Republic of China and engaged in the business of books, newspapers, periodicals and drawings does not need to obtain patent use rights from the patent holder and does not need to pay the patent fee for the MPR code symbol to the patent holder forever. At the same time, he is willing to negotiate with any applicant other than a publishing organization registered in China with a book, newspaper and periodical business on patent licensing under reasonable and non-discriminatory terms and conditions. The statement of the patent holder has been filed with the issuing agency of this document. Relevant information can be obtained through the following contact information: Name of patent and holder: Shenzhen Tianlang Times Technology Co., Ltd. Address: 105 Meihua Road, Futian District, Shenzhen, Technology Building, 1st Floor, Duoli Industrial Park. Please note that in addition to the above patents, some contents of this document may still involve patents. The issuing agency of this document does not assume the responsibility for identifying these patents.
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1 Scope
GB/T 27937. 2—2011
MIPR Publication: Part 2: MPR Code Symbol Specification This part of GB/T27937 specifies the structure, data encoding, symbol generation method and symbol quality level of MPR code symbols used in MPR publications.
This part applies to the generation, recognition and quality level determination of MPR code symbols. 2 Normative references
The following documents are indispensable for the application of this document. For dated references, only the dated version applies to this document. For undated references, the latest version (including all amendments) applies to this document: GB/T 1988-1998 Information technology Seven-bit coded character set for information interchange (CAVI 50/IEC 646: 1991) GB/T 12905-2000 Barcode terminology
GB/T 27937.1 MPR publication Part 1: MPR code coding specification 3 Terms and definitions
Terms and definitions defined in GB/T 12905-2000 and GB/T 27937.1 and the following terms and definitions apply to this document. For ease of use, some terms and definitions in GB/T 12905-2000 and GB/T 27937.1 are repeated below. 3. 1
Multimedia print reader: MPR publication
A composite publication that uses MPR codes to associate digital media files such as audio and video with printed images and texts, achieving synchronous presentation and satisfying the readers’ audio-visual needs. It is composed of printed materials such as MPR books and newspapers, digital media files such as audio and video, and MPR codes that establish precise association between the two.
[GB/T 27937.1—2011 definition 3.1] 3.2
MPR codeMPRcode
A shortened code used to uniquely associate the printed images and texts in MPR publications (3.1) with the related digital media files such as audio and video, so as to establish a precise association relationship for the purpose of common presentation. [GB/T27937.1—2011.Definition 3.2]
MPR code symbol MPR code synbol
A matrix-type two-dimensional code symbol that complies with the specifications set forth in this section and is used to carry the MPR code (3.2) and is fixed on the printed page in a printed manner for identification and reading by photoelectric equipment. GB/T 27937.1——2011, X 3.3
Positioning dot
The mark indicating the start and end positions in the MPR code symbol. The shape of the positioning dot is a circle or a regular polygon. 1
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GB/T 27937.22011
Code dot
The mark indicating valid data information in the MPR code symbol. The shape of the code dot is a circle or a regular polygon. 3.6
Duty Cyele
The ratio of the maximum length of a code point in the horizontal or vertical direction to the distance between the centers of adjacent code points, 3.7
Module
The basic unit of MPR code symbols, including the anchor point (3.4) and the code point (3.5). 3.8
Module dimension
The parameter indicating the size of the code point or anchor point in the MFR code symbol. It is the length of the longest line segment passing through the center point of the module pattern in the horizontal or vertical direction. 3.9
Masking
In order to make the distribution of dark and light modules in the symbol balanced and reduce the pattern of interference with image recognition, the pattern of the comb pattern is XORed with the pattern of the code area in the coding area. 3.10
Symbol combination
Arrange multiple MPR code symbols regularly so that the anchor points of adjacent symbols are shared, and form a large area of ​​MPR code symbols tiled arrangement.
Symbol's contrast symbol's contrast
The difference between the maximum reflectivity and the minimum reflectivity of the optical reflectivity distribution in the MPR code symbol. 3.12
Printed increment
The size change of the module (3.7) caused by oil diffusion or insufficient ink during the printing process of the MFR code symbol. 3.13
Axial direction discordanceThe average size difference between the center points of each module in the symbol in the horizontal and vertical directions after the MPR code symbol module is printed (or sampled).
4 Conventions
This standard uses numbers starting with 0x to represent hexadecimal numbers. This standard uses 1 byte (8 bits) as the bit length and width of the codeword, and uses W to represent the codeword, W represents the first codeword, and W represents the second codeword.
This standard uses α| to represent the absolute value of the number α. 5 Special code structure
5.1 Basic characteristics
5. 1. 1 Function
The MPR code symbol is a matrix two-dimensional code with an independent positioning function for automatic identification. 2
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5.1.2 Encoded character data type
The encoded character data type is the number in B/1988. 5.1.3 Symbol structure diagram
The symbol structure of the MPR code is shown in Figure 1.
Figure 1 MPR code symbol structure diagram
GB/T 27937.2—2011
The symbol of the MPR code consists of 96 code points or spaces arranged evenly and 4 positioning points. The module size of the positioning points is twice the size of the code point module.
The side length point space ratio of the MPR code symbol is 1:4~1:3. The code width inverse length of the MPR code symbol should be 1.63 mm, and the average side length of the MPR code symbol of the joint piece should be 1.52 mm. The nominal value of the code point module size is recommended to be 0.05 mm. The maximum allowable module size of the MPR code symbol after printing is 0.07 mmtm, and the minimum is 0.03 mm. 5. 1. 4 Data representation method
The code point represents the binary number 1, and the space represents the binary number 0. The symbol of the MPR code can represent 96 binary numbers, corresponding to 12 8-bit binary digital words. The 12 code words P, W, ~ W, are the effective data codes of the MPR code, and W, ~ W1 are the error correction code words of the MPR code. 5. 1. 5 Mask
The mask diagram of the MPR code symbol is shown in Figure 2.
Figure 2 Mask diagram of MPR code symbol
The MFR code symbol uses the mask diagram shown in Figure 2 (dark dots represent 1, and no dark dots represent 0) to perform XOR processing on the 96-bit binary number at each identical position.
5.1.6 Codeword layout
The 96-bit binary number corresponding to the MPR code derivative number constitutes 12 codewords according to the codeword layout in Table 1, and the coordinate origin of the codeword in the symbol is the upper left corner.
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GB/T 27937.2—2011
Code word sequence
Code quantity
Table 1 Code word layout of MPR code symbol
The coordinates of the code word in the symbol (none, 3), the arrangement order is from high to low (bit7~bito)(1,0), (2.02. (0,1), (1,1), (2,1), (0,2), (1.2), (2,2)(3,0),(4.0),(5,0),(6,0),(3,1),(4+1),(5,1),(6.1)(7,0),(8+0),(7,1),(8.1),(9,1),(7,2),(8,2),(9,2)(3,2),(4.2).(2,3),(3,3), (4.3),(2.4),(3,4),(4+4)(5,2), (6,2)(5.3),(6,3), (7.3), (5.4), (6,4), (7.4)(0,3),(1,3),(0,4),(1,4),(0,5),(1,5),(0,6),(1.6)(8,3), ( 9,3),(8+4),(9,4),(8,5),(9.5),(8,6), (9,56)(2,5),(3,5),(4,5),(2.6),(3.6),(4,6),(3.7),(4,7)(5.5), (6.5),(7,5),(5,6), (6,6), (7,6), (5,7), (6,7)(0.7), (1,7),(2,7), (0.8) (1,8), (2,83, (1,9), (2,9)(3.8), (4.8), (5,8), (6.8). (3,9), (4,9), (59), (6,9)(7.7),(8,7), (9,7),(7.8)+(8,8), (9,8), (7,9), (8,9)MPR code symbols do not need to be processed by multiple character set encoding. The coded character data can be directly converted into binary data for graphic encoding. The 7 valid coded character data codewords have a total of 56 binary bits. The capacity of the MPR code is 256=72057594037927936 (data representation range: 0--72057594037927935). 5.1.8 Error correction method
MPR code symbols use the Reed- Solomon error correction (RS error correction) algorithm, the code bit length is 8 bits. MPR code symbols use 5-byte error correction code and 7-byte coded character data, which can correct 2-byte errors and detect 3-byte errors. The primitive polynomial used by the MFR code symbol error correction algorithm to construct the GF(256) field is +15+1*+1; the generating polynomial of the RS error correction code is "621*+111-15*+48-228". 5.2 Symbol diagram
The MPR code symbol diagram example is shown in Figure 3.
Figure 3 MPR code symbol diagram example
5.3 Symbol connection
When it is necessary to increase the MPR code symbol area, multiple identical MPR code symbols can be symbol-connected. The symbol connection diagram of the MPR code is shown in Figure 4.
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6 Data Coding and Symbol Generation
Figure 4 Example of special number connection diagram of MPR code
The steps of data reduction coding and generating MPR code symbols are as follows. GB/T27937.2-2011
Input digital coded data and divide the data into 7-byte byte sequences. For example, the input information code data is 0x123456789ABCDE, and the byte sequence after division is 0x12.0x34,0×56.0x78.0×9A0BC.0xDE. b) Perform RS error correction coding operation on the 7-byte sequence to generate a 5-byte error correction codeword. c)
The error correction codeword is sequentially spliced ​​after the sequence of 7-byte information codewords to form a codeword sequence of 12-byte MPR code symbols. d) Generate a basic bitmap based on the 12 codewords. According to the data representation method of 5.1,4 and the codeword layout in Table 1, the 96-bit streams of the 12 codewords are correspondingly generated into a basic bitmap. Mask: The basic bitmap is subjected to a bitwise XOR operation using the mask shown in Figure 2. If the result is 1, a codepoint is placed at the corresponding c
position in the output bitmap. Otherwise, there is no codepoint (i.e., a vacant position) at that position. Finally, positioning points are added to the four corners of the output bitmap. f
7 Quality of MPR code symbols
7.1. Special symbol quality grading
Under given lighting and observation conditions, obtain a high-resolution grayscale image of an MPR code symbol, and then analyze the parameters such as decoding, symbol contrast, printing gain, axial inconsistency, etc. of the stored image to determine the symbol quality grade, which is used to evaluate the printing quality of the MPR code symbol. The quality grading of symbols is shown in Figure 2. Table 2 Symbol quality grading
Symbol contrast
70%25>5%
55%≥50>40%
40%≥5C>20%
Printing enhancement
0.50≤D0.50
0.70≤D≤0. 70
0. 85≤D'≤0. 85
1. 00≤D≤1. 00
D'≤-1. 00
or D'≥1. 00
The quality grade of the entire symbol is determined as the lowest grade that the above parameters can reach. TTTKANTKACA
Directional inconsistency
AN≤0.06
AN≤0.0B
AN≤0. 12
Quality inspection and judgment
Unqualified
GB/T 27937.2—2011
7.2 Evaluation of symbol cost
7.2. 1 Decoding
Decode according to the method in Appendix A of this part. When the decoding is successful, the decoding level is "4", otherwise it is \o\7.2. 2 Symbol contrast
In the test grayscale image, the grayscale distribution of the image index values ​​in the MPR code symbol area is counted, the darkest 5% and the brightest 5% of the pixels are selected, and the arithmetic mean of the reflectivity of the darkest 5% and the arithmetic mean of the reflectivity of the brightest 5 are calculated. The difference between these two average values ​​is the symbol contrast SC
The symbol contrast level is determined as follows:
SC>70%
70%SC>55%bzxz.net
55%2SC>40%
40%250>20%
SC≤20%
O (E unqualified)
The symbol contrast parameter is used to measure whether the reflection state of the dark module and the light module in the symbol is sufficiently different throughout the entire symbol.
7.2.3 Printing increment
According to 7.2.2, calculate the median of the arithmetic mean of the light and dark grayscales, and use the result as the reference value to act on the grayscale image to produce a binary image.
Printing increment is the degree to which the edge of the dark module in the symbol invades the light module area due to ink diffusion, or the degree to which the light module invades the dark module area. When the MPR code symbol is printed in the bottom-laying method, the printing increment is an important indicator that affects the grayscale visual effect of the MPR code matrix. The module size of the code point is used as a reference to evaluate the self-standard parameters, and the levels of the horizontal and vertical left-hand module sizes are calculated respectively. The lower level of the two is taken as the printing increment level of the code point; the printing increment level of the MPR code symbol is the lowest level of the printing increments of all the code points that constitute the symbol. The nominal value of the code point module size is specified as D0x, the maximum allowable value is LM4x, and the minimum value is Dm. Normalize the measured value D to its nominal and limit values: If D>DNoM
D'=(D-Dnom)/(Dux-DuN)
D'=(D-Dno>/(Dnow-DmN)
The level of printed increment is determined as follows:
-0.50≤D≤0.50
0.70≤D≤0.70
0.85≤D≤0. 85
-1. 00≤D≤1, 00
D'≤-1. 00 or D>1. 00
7.2.4 Axial inconsistency
0 (E failure)
The MPR code symbol contains a data area composed of code points. The center points of these code points are located in a regular polygonal grid. The decoding method must map the center positions of these modules to obtain data. Axial inconsistency refers to the distance to the center of the image, that is, the amount and classification of the spacing between the sample points in the horizontal and vertical axes of the grid. For each code point in the symbol, take its center point, and then count the average value X and the distance between the center points of the code points in the horizontal x direction and the vertical ? direction respectively. The axial inconsistency parameter is as follows: AN = |(XAG-Ya)/((XaG + YAr)/2)|6
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Determination of axial inconsistency level
When AN≤0.06
When AN≤0, 08
When AN≤0.10
When AN≤0.12
When AN>D. 12
GB/T 27937. 2—2011
GB/T27937.2--2011
A,1MPR code decoding process
The decoding process of MPR code is shown in Figure A,1.
Image processing
Image binarization
Luqing Kangyuan
Find out all code points and positioning points
Statistic their area true square diagram
Find out all positioning points according to the code point area histogram
Appendix A (Scientific Appendix) Reference decoding method Find the same group of positioning points Cast the code point in the blocking positioning point Obtain the 12 code words of the MPR code according to the group of positioning points and the code points Perform RS decoding on the 12 code words to obtain the MPR code MPR code decoding flow chart Note: The same group mentioned in Figure A.1 refers to being in the same MPR code pattern. A.2 Find the same group of positioning points The judgment basis is that the 4 positioning points in the same group must form a square. The method is as follows 82 Calculate 5 as the median of the arithmetic mean of the light and dark grayscales, and use the result as the reading value to act on the grayscale image to produce a binary image.
The printing increment is the degree to which the edge of the dark module in the symbol invades the light module area due to ink diffusion, or the degree to which the light module invades the dark module area. When the MPR code symbol is printed in a bottom-laying manner, the printing increment is an important indicator that affects the grayscale visual effect of the MPR code array. The module size of the code point is used as a reference to evaluate the self-standard parameters, and the levels of the horizontal and vertical left-hand module sizes are calculated respectively. The lower level of the two is taken as the printing increment level of the code point; the printing increment level of the MPR code symbol is the lowest level of the printing increments of all the code points that constitute the symbol. The nominal value of the code point module size is specified as D0x, the maximum allowable value is LM4x, and the minimum value is Dm. Normalize the measured value D to its nominal and limit values: If D>DNoM
D'=(D-Dnom)/(Dux-DuN)
D'=(D-Dno>/(Dnow-DmN)
The level of printed increment is determined as follows:
-0.50≤D≤0.50
0.70≤D≤0.70
0.85≤D≤0. 85
-1. 00≤D≤1, 00
D'≤-1. 00 or D>1. 00
7.2.4 Axial inconsistency
0 (E failure)
The MPR code symbol contains a data area composed of code points. The center points of these code points are located in a regular polygonal grid. The decoding method must map the center positions of these modules to obtain data. Axial inconsistency refers to the distance to the center of the image, that is, the amount and classification of the spacing between the sample points in the horizontal and vertical axes of the grid. For each code point in the symbol, take its center point, and then count the average value X and the distance between the center points of the code points in the horizontal x direction and the vertical ? direction respectively. The axial inconsistency parameter is as follows: AN = |(XAG-Ya)/((XaG + YAr)/2)|6
TTTKAONTKACA
Determination of axial inconsistency level
When AN≤0.06
When AN≤0, 08
When AN≤0.10
When AN≤0.12
When AN>D. 12
GB/T 27937. 2—2011
GB/T27937.2--2011
A,1MPR code decoding process
The decoding process of MPR code is shown in Figure A,1.
Image processing
Image binarization
Luqing Kangyuan
Find out all code points and positioning points
Statistic their area true square diagram
Find out all positioning points according to the code point area histogram
Appendix A (Scientific Appendix) Reference decoding method Find the same group of positioning points Cast the code point in the blocking positioning point Obtain the 12 code words of the MPR code according to the group of positioning points and the code points Perform RS decoding on the 12 code words to obtain the MPR code MPR code decoding flow chart Note: The same group mentioned in Figure A.1 refers to being in the same MPR code pattern. A.2 Find the same group of positioning points The judgment basis is that the 4 positioning points in the same group must form a square. The method is as follows 82 Calculate 5 as the median of the arithmetic mean of the light and dark grayscales, and use the result as the reading value to act on the grayscale image to produce a binary image.
The printing increment is the degree to which the edge of the dark module in the symbol invades the light module area due to ink diffusion, or the degree to which the light module invades the dark module area. When the MPR code symbol is printed in a bottom-laying manner, the printing increment is an important indicator that affects the grayscale visual effect of the MPR code array. The module size of the code point is used as a reference to evaluate the self-standard parameters, and the levels of the horizontal and vertical left-hand module sizes are calculated respectively. The lower level of the two is taken as the printing increment level of the code point; the printing increment level of the MPR code symbol is the lowest level of the printing increments of all the code points that constitute the symbol. The nominal value of the code point module size is specified as D0x, the maximum allowable value is LM4x, and the minimum value is Dm. Normalize the measured value D to its nominal and limit values: If D>DNoM
D'=(D-Dnom)/(Dux-DuN)
D'=(D-Dno>/(Dnow-DmN)
The level of printed increment is determined as follows:
-0.50≤D≤0.50
0.70≤D≤0.70
0.85≤D≤0. 85
-1. 00≤D≤1, 00
D'≤-1. 00 or D>1. 00
7.2.4 Axial inconsistency
0 (E failure)
The MPR code symbol contains a data area composed of code points. The center points of these code points are located in a regular polygonal grid. The decoding method must map the center positions of these modules to obtain data. Axial inconsistency refers to the distance to the center of the image, that is, the amount and classification of the spacing between the sample points in the horizontal and vertical axes of the grid. For each code point in the symbol, take its center point, and then count the average value X and the distance between the center points of the code points in the horizontal x direction and the vertical ? direction respectively. The axial inconsistency parameter is as follows: AN = |(XAG-Ya)/((XaG + YAr)/2)|6
TTTKAONTKACA
Determination of axial inconsistency level
When AN≤0.06
When AN≤0, 08
When AN≤0.10
When AN≤0.12
When AN>D. 12
GB/T 27937. 2—2011
GB/T27937.2--2011
A,1MPR code decoding process
The decoding process of MPR code is shown in Figure A,1.
Image processing
Image binarization
Luqing Kangyuan
Find out all code points and positioning points
Statistic their area true square diagram
Find out all positioning points according to the code point area histogram
Appendix A (Scientific Appendix) Reference decoding method Find the same group of positioning points Cast the code point in the blocking positioning point Obtain the 12 code words of the MPR code according to the group of positioning points and the code points Perform RS decoding on the 12 code words to obtain the MPR code MPR code decoding flow chart Note: The same group mentioned in Figure A.1 refers to being in the same MPR code pattern. A.2 Find the same group of positioning points The judgment basis is that the 4 positioning points in the same group must form a square. The method is as follows 8
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