User`s manual

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By raising the edge height value to 6, the SLS no longer
detects an edge on the clutter object, since its contrast
(amplitude) is too low for the higher edge height value.
Figure 6.11 shows the result. Note that the small “x” is now
located on the first edge of the inspected object.
Fgure 8.11 Edge tieigM Adjustment: Aesutts
First edge now detected
on inspected object
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Edge Span
The edge span parameter specifies the span or distance
along the FOV within which the specified change in image
contrast (amplitude) must take place. Edge span values
range from 1 to 10. The larger the edge span value, the
greater the distance along the FOV that the SLS must
evaluate in order to detect the specified change in contrast.
Thus, if a visual “noise spike” appeared in the FOV, the
contrast changes from white to black, and black to white
again, within a very short distance. When the edge span
value is set high enough, however, the SLS ignores the
spike, since the net contrast change, from the beginning to
the end of the specified span, is zero (or nearly zero).
Figure 6.12 on page 6-14 shows part of the View Port for
the objects shown in Figure 6.11, above In this example, the
edge height value is 3 (as in Figure 6.10, page 6-12), but
the edge span value is 10, the maximum. Note that the SLS
did not detect an edge on the “clutter” object, since the
object’s “span” was smaller than the distance that the SLS
evaluated with an edge span value of 10. The SLS did
detect an edge on the inspected object, however, since it
met the specified contrast change (edge height) over the
specified distance (edge span).
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