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Smart Camera / Vision-Sensor / 1D-/2D-Code-Scanner / OCR Reader
Construction
Method
Edge on Arc
The construction method is the same as for “edge on line”. The difference is the search
geometry. In the case of “edge on line”, edge jumps are looked for along a line. In the
case of “edge on arc”, edge jumps are looked for on an arc.
Edge Polarity Expected Brightness Characteristics
Either
Both bright to dark and dark to bright transitions
are searched for.
Bright to Dark
Only bright to dark transitions are searched for.
Dark to Bright
Only dark to bright transitions are searched
for.
Find by This parameter can be used to specify which of the detected edges
will be used on the search line.
Best Score
If several edge transitions are detected on the
search line, the transition with the greatest con-
trast is selected.
First Score
If several edge transitions are detected on the
search line, the first transition in the search direc-
tion is selected.
Last Score
If several edge transitions are detected on the
search line, the last transition in the search direc-
tion is selected.
Edge Width
(px)
“Edge width” influences detection sensitivity for brightness fluctua-
tions. Note: An edge width of 3 pixels reacts to even the smallest
contrast change in the image. An edge width of 9 pixels smooths
the brightness profile over a distance of 9 pixels and ignores small
irregularities.
Threshold
Gradient Pos
(GrM)
Threshold Gradient Pos specifies the positive gradient acceptance
threshold.
Note: The gradient corresponds to the change in brightness from
one pixel to the next. The higher the edge’s contrast, the larger the
gradient.
Threshold
Gradient Neg
(GrM)
Threshold Gradient Neg specifies the negative gradient accep-
tance threshold.
Note: The gradient corresponds to the change in brightness from
one pixel to the next. The higher the edge’s contrast,
the larger the gradient.
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