Datalogic Matrix 400, Manual, Page: 38 / 86

MATRIX 400™ CODE QUALITY VERIFIER SOLUTION
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Axial Non-Uniformity (ANU)
Measures and grades the squareness of all modules in the direction of each of the symbol’s
major axes (X-axis and Y-axis) by applying the decode algorithm to the binarized image.
Decode
This parameter tests, on a Pass/Fail basis, whether the symbol has all its features sufficiently
correct. If the image cannot be decoded using the symbology reference decode algorithm,
then it shall receive the failing grade 0. Otherwise, it shall receive the grade 4.
Fixed Pattern Damage (FPD)
This parameter tests that damage to the Finder Pattern, Quiet Zone, Clock and other fixed
patterns in a symbol does not reduce unacceptably the ability of the reference decode
algorithm to locate and identify the symbol within the field of view, by inverting the apparent
state of one or more modules from Light to Dark or vice versa.
The particular patterns to be considered, and the amounts of damage corresponding to the
various grade thresholds, require to be specified independently for the Symbology
concerned.
Grid Non-Uniformity (GNU)
Measures and grades the largest vector deviation of the grid intersections, determined by the
reference decode algorithm from the binarized image of a given symbol, from their “ideal”
theoretical position.
Assuming a grid on which the ideal angle of intersection is 90°, any angle deviation from 90°
constitutes Grid Non-Uniformity.
Y
X
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