ICS 35.040
Ref. No. ISO/IEC 15415:2004/Cor.1:2008(E)
© ISO/IEC 2008 – All rights rerved Published in Switzerland
INTERNATIONAL STANDARD ISO/IEC 15415:2004
TECHNICAL CORRIGENDUM 1
Published 2008-10-01
INTERNATIONAL ORGANIZATION FOR STANDARDIZATION • МЕЖДУНАРОДНАЯ ОРГАНИЗАЦИЯ ПО СТАНДАРТИЗАЦИИ • ORGANISATION INTERNATIONALE DE NORMALISATION INTERNATIONAL ELECTROTECHNICAL COMMISSION • МЕЖДУНАРОДНАЯ ЭЛЕКТРОТЕХНИЧЕСКАЯ КОМИССИЯ • COMMISSION ÉLECTROTECHNIQUE INTERNATIONALE
Information technology — Automatic identification and data capture techniques — Bar code print quality test specification — Two-dimensional symbols
TECHNICAL CORRIGENDUM 1
Technologies de l'information — Techniques automatiques d'identification et de capture des données — Spécification de test de qualité d'impression des symboles de code à barres — Symboles bi-dimensionnels秦明的绰号
完整的招商方案
RECTIFICATIF TECHNIQUE 1
Technical Corrigendum 1 to ISO/IEC 15415:2004 was prepared by Joint Technical Committee ISO/IEC JTC 1, Information technology , Subcommittee SC 31, Automatic identification and data capture techniques .第一时间报
ISO/IEC 15415:2004/Cor.1:2008(E)
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© ISO/IEC 2008 – All rights rerved
Page 17
Replace 7.8.4 with the following:
7.8.4 Modulation and related measurements 7.8.4.1 Modulation
Modulation is a measure of the uniformity of reflectance of the dark and light modules respectively. Factors such as print growth (or loss), misplacement of a module relative to the grid interction, the optical characteristics of the substrate and uneven printing may reduce the difference between the reflectance of a module and the Global Threshold. A low Modulation may increa the probability of a module being incorrectly identified as dark or light.
The reflectance value of each module in the symbol shall be measured by superimposing on the reference grey-scale image the grid determined by applying the symbology reference decode algorithm to the binarid image. Calculate MOD, the Modulation value of each module as follows:
MOD = 2 * (abs (R – GT )) / SC where MOD = modulation
R is the reflectance of the module GT is the Global Threshold
SC is the Symbol Contrast
Assign the grade level for each module according to Table 6. For each codeword, lect the minimum modulation grade of all modules in the codeword. As suggested by the absolute value in the function for MOD, whether a codeword is decoded correctly has no bearing on the grade level that is assigned. In this way, Modulation differs from Reflectance Margin, e 7.8.4.3.
Table 6 — Module grading for Modulation and Reflectance Margin
MOD or MARGIN
Module Grade ≥ 0,50 4 ≥ 0,40 3 ≥ 0,30 2 ≥ 0,20
1 < 0,20
ISO/IEC 15415:2004/Cor.1:2008(E)
© ISO/IEC 2008 – All rights rerved
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The cumulative number of codewords achieving each grade shall be counted and compared with the error correction capacity of the symbol as follows:
For each grade level, assuming that all codewords not achieving that grade or a higher grade are errors, derive a notional Unud Error Correction grade as described in 7.8.8. Take the lower of the grade level and the notional UEC grade.
NOTE This notional grade is not related to, and does not affect, the UEC grade for the symbol as calculated according to 7.8.8, but is a means of compensating for the extent to which error correction can mask imperfections in a symbol. If one symbol has higher error correction capacity than another symbol, then the former symbol can tolerate a greater number of codewords with low modulation than the latter. See Annex F for a fuller description of the approach.
Then the Modulation grade for the symbol shall be the highest of the resulting values for all grade levels. When the symbol consists of more than one (e.g. interleaved) error correction block, each block shall be assd independently and the lowest grade for any block shall be taken as the Modulation grade of the symbol.
Table 7 shows an example of grading Modulation in a symbol containing 120 codewords, 60 of which are error correction codewords with a capacity to correct up to 30 errors in a single error correction block. Modulation grade of the symbol in the example would be 2 (the highest value in the right-hand column).
Table 7 — Example of Modulation grading in a two-dimensional matrix symbol MOD codeword grade level
(a )
No. of
codewords at level a
Cumulative no. of codewords at
level a or higher (b )
Remaining codewords (treated as errors) (120 - b ) (c )
Notional unud error correction capacity (30 – c )
Notional
UEC (%)
Notional
UEC grade
(d ) Lower of a or d (e )
4 2
5 25 95 (exceeded) <0 0 0 3 75 100 20 10 33,3% 1 1 2 15 115 5 25 83,3% 4 2
1 3 118
拜年话语
2 28 93,3% 4 1
0 2 120 0 30 100% 4 0
Modulation grade
(Highest value of e):
2
In this example, some codewords may contain errors but that does not affect the calculation. 7.8.4.2 Contrast Uniformity
Contrast Uniformity is an optional parameter that can be a uful process control tool for measuring localized contrast variations. Contrast Uniformity does not affect the overall grade.
ISO/IEC 15415:2004/Cor.1:2008(E)
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做自己作文© ISO/IEC 2008 – All rights rerved
Contrast Uniformity is defined as the minimum MOD value found in any module contained in the data region of the symbol in 7.8.4.1.
7.8.4.3 Reflectance Margin
Reflectance Margin is a measure of how well each module is correctly distinguishable as light or dark in comparison to the global threshold. Factors such as print growth (or loss), misplacement of a module relative to the grid interction, the optical characteristics of the substrate, uneven printing, or encodation errors, may reduce or even eliminate the margin for error between the reflectance of a module and the Global Threshold. A low Reflectance Margin may increa the probability of a module being incorrectly identified as dark or light. The reflectance value of each module in each codeword in the symbol shall be measured by superimposing on the reference grey-scale image the grid determined by applying the symbology reference decode algorithm to the binarid image.
Since the correct state of each module is known after decoding, any modules which are decoded incorrectly are assigned a MARGIN value of 0.
For modules who correct state is light:
MARGIN = 2 * (R – GT) / SC for R ≥ GT MARGIN = 0 for R < GT
and for modules who correct state is dark:
MARGIN = 2 * (GT – R) / SC for R < GT MARGIN = 0 for R ≥ GT Where
MARGIN = the reflectance margin of the module R is the reflectance of the module GT is the Global Threshold SC is the Symbol Contrast
Assign the grade level for each module according to Table 6. For each codeword, lect the minimum grade for MARGIN of all modules in the codeword. Since codewords which are misdecoded are given grade level of 0, Reflectance Margin differs from Modulation, e 7.8.4.1.
The cumulative number of codewords achieving each grade shall be counted and compared with the error correction capacity of the symbol as follows:
For each grade level, assuming that all codewords not achieving that grade or a higher grade are errors, derive a notional Unud Error Correction grade as described in 7.8.8. Take the lower of the grade level and the notional UEC grade.
NOTE This notional grade is not related to, and does not affect, the UEC grade for the symbol as calculated according to 7.8.8, but is a means of compensating for the extent to which error correction
can mask imperfections in a symbol. If one symbol has higher error correction capacity than another symbol, then the former symbol can tolerate a greater number of codewords with low modulation than the latter. See Annex F for a fuller description of the approach.
Then the Reflectance Margin grade for the symbol shall be the highest of the resulting values for all grade levels.
ISO/IEC 15415:2004/Cor.1:2008(E)
© ISO/IEC 2008 – All rights rerved
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Table Cor.1-1 shows an example of grading Reflectance Margin in a symbol containing 120 codewords, 60 of which are error correction codewords with a capacity to correct up to 30 errors in a single error correction block. The Modulation grade of the symbol in the example would be 2 (the highest value in the right-hand column).
Table Cor.1-1 — Example of Reflectance Margin grading in a two-dimensional matrix symbol, applying
荒草萋萋
overlay procedure in Annex F
绘制流程图MARGIN codeword grade level
(a )
No. of
codewords at level a
Cumulative no. of codewords at
level a or higher (b )
Remaining codewords (treated as errors) (120 - b ) (c )
Notional unud error correction capacity (30 - c )
Notional UEC (%)
Notional UEC grade (d )
Lower of a or d (e )
4 1
5 15 105 (exceeded) <0 0 0 3 70 85 35 (exceeded) <0 0 0 2 15 100 20 10 33,3% 1 1 1 5 105 15 15 50% 3 1
放大镜英语0 15 120 0 30 100% 4 0
Reflectance Margin
grade (Highest value
of e):
1
This example reprents values from the same symbol ud in Table 7. However, in this example ten codewords from level 4 and five codewords from level 3 are detected to contain at least one module which is on the wrong side of the global threshold and are therefore errors. The codeword
s are therefore counted at level 0 in this example. The resulting grade too is changed significantly.
