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Vision Sensor SBSI/SBSC-EN, 8062650 - 1607b - 13/09/2016
Vision Sensor Manual
Fig. 137: Detector Barcode, tab Quality
Settings in tab Quality
Parameters Functions
Quality
param.
Evaluation of printing quality according to international standard ISO/IEC 15416.
In order to achieve an evaluation according to the norm, there are defined minimum
requirements for the size of the code inside the camera image (resolution) and mounting
of camera and illumination. These requirements are specified inside the norm.
For simple 1D Barcodes, the rating of printing quality is combined in a total of eight
elements:
Q1 Overall
Q2 not used
Q3 not used
Q4 Minimal Reflectance
Q5 Minimal Edge contrast
Q6 Modulation
Q7 Defects
Q8 Decodability
"Overall" is rating the total quality, the further elements give information about possible
reasons for a reduced quality.
Inside ISO/IEC15416 there is a list with common defects and their influence to the single
grades.
The single quality grades are defined as follows:
"Overall" is the minimum value of all other grades.
"Decode" has value 4 when the code was read and value 0 when the code was not read.
"Symbol contrast" is the difference between minimum and maximum reflexion value of
greyscale, better contrast gives better grading.
"Minimal reflectance" is set to 4 if the lowest reflectance value in the scan reflectance
profile is lower or equal to 0.5 of the maximal reflectance value. Otherwise a value of 0
is assigned.
"Edge contrast" is the contrast between any two adjacent elements, either bar-to-space
or space-to-bar. The "minimal edge contrast" grades the minimum of the edge contrast
values measured in the reflectance profile.
"Modulation" indicates how strong the amplitudes of the bar code elements are. Big
amplitudes make the assignment of the elements to bars or spaces more certain,
resulting in a high modulation grade.
"Defects" is a grading of reflectance irregularities found within elements and quiet zones.
"Decodability" grade reflects deviations of the element widths from the nominal widths
defined for the corresponding symbology.
"Additional requirements" are bar code symbology specific requirements: mostly
regarding the required quiet zones, but sometimes it can be also related to wide/narrow
ratio, inter character gaps, guarding patterns or further symbology specific
characteristics.
For composite codes, the rating has 24 grades:
OVERALL:
Q1 Overall
Q2 Overall Linear
Q3 Overall Composite
Summary of Contents for SBSC-EN
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