Adept AdeptSight User Guide - Manual (Page 381)

Configuring Edge Locator Properties
Filter Mode
Determines the edges that will be returned from the tool, as follows:
All, First Edge, Last Edge, Middle
Magnitude Threshold
Sets the acceptable magnitude value for potential edges. This value is expressed as an abso-
lute value. There are two magnitude lines: an upper (positive) threshold and lower (negative)
threshold.
Possible values are from 0 - 255.
Edge Magnitude expresses the strength of a potential edge. The (green) magnitude curve,
represents magnitude values across the region of interest. Potential edges must have a mag-
nitude greater than the upper threshold, or lower than the lower threshold. See the following
figure.
Interpreting the Magnitude Threshold in the display
area
l
All peaks on the edge magnitude curve that fall between the two red magnitude
threshold lines are not considered.
l
All peaks on the edge magnitude curve that are above the upper threshold or below
the lower threshold are considered as potential edges.
l
Sometimes unwanted edges, such as those corresponding to shadows, have mag-
nitude values CLOSE to those of valid edges. When possible, do NOT use the mag-
nitude threshold to reject such edges because in some images, lighting variations may
cause edges of interest to also fall below the threshold. Instead, use polarity and posi-
tion constraints that are not affected by lighting variations from one image to another.
Configuring Edge Locator Properties
AdeptSight User's Guide, Version 3.2.x, Updated: 8/23/2012
Page 381