Rockwell Automation 5370-CVIM2 Module - Manual (Page 444)

5 Chapter Chapter 8
Thresholds, Filters, and Morphology
8–5
value that results in consistent edges being detected at the desired reference
points on the workpiece image.
Figure 8.4 provides an example of setting the filter value so that the
superfluous “edges” are masked or filtered out. This example shows three
stages of setting the filter value for a linear gage that lies across a portion of a
workpiece image.
Figure 8.4 Example: Filtering the White “Noise” in a Workpiece Image
Filter setting = 1
Filter setting = 2
Filter setting = 3
A
B
C
Portion of workpiece image
With the filter value currently set to “1,” numerous unwanted “edges” (“+”
symbols) appear along the gage, as shown in part A of Figure 8.4. In part B,
the filter is set to “2,” and fewer unwanted edges are detected. In part C, the
filter is set to “3,” and only the desired edges are detected.
Exit the Binary Filter panel by picking the button.
Your main objective in setting the gray scale threshold is to define the most
stable edges along the gage where the gaging tool crosses the proposed
reference points on the workpiece.
Gray scale edge detection uses two parameters to analyze the image and
detect edges. These parameters are called threshold and kernel.
Gaging Tools: Gray Scale
Edge Detection