Threshold functions – Rockwell Automation 5370-CVIM2 Module User Manual

Page 429

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5

Chapter

Chapter 7

Inspection Tools

7–191

The

Width

box enables the selection of one of several sub–gage widths. The

default width setting is 1 pixel, but a wider setting may be necessary if a
particular edge is somewhat uneven. In that case, a wider setting has the
effect of smoothing an uneven edge by calculating its average location across
the width of the gage.

The kernel setting determines the number of consecutive pixels over which
the brightness change is evaluated. At a given point, the brightness change is
evaluated over a distance equal to two times the kernel setting, plus one.

The kernel setting is 3 by default. This means that an edge will be detected
whenever a “rising” or “falling” brightness change occurs (as determined by
the

Thresholds

settings) within three consecutive pixels along the length of

the gage. A higher setting may be necessary to detect an edge where the
brightness change is more gradual.

The kernel value can be adjusted by sliding the cursor up or down, or by
clicking the “box” containing the kernel value. In that case, the calculator
pad will appear, and a value between 1 and 16 can be entered.

For more detailed information about kernels, refer to the Threshold and
Kernel Settings
section on page 8–6.

When you pick the

Threshold

field in the multiple gages tool edit panel, the

Gage Threshold

panel appears, as shown in Figure 7.153.

Figure 7.153 Gage Threshold Panel

Threshold Functions

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