Rockwell Automation 5370-CVIM2 Module - Manual (Page 462)

5 Chapter Chapter 8
Thresholds, Filters, and Morphology
8–23
When configured as shown in (A) of Figure 8.18, where all of the kernel’s
seven boxes have asterisks (for both
Max and Min ), the effect of the Max –
Min function is to detect all edges around objects within the inspection
window. Thus, the circular black objects shown in (A) of Figure 8.19 are
shown with their edges “detected” (highlighted) all around in (B) of
Figure 8.19.
Figure 8.19 Example: Filtering Effect of Max – Min Function With All Asterisks Set
A
B
When configured as shown in (B) of Figure 8.18, where just the three
adjacent horizontal boxes have asterisks (they must be the same three
horizontal boxes for both
Max and Min ), the effect of the Max – Min
function is to “detect” only the vertical edges on objects within the
inspection window. Thus, the rectangular black objects shown in (A) of
Figure 8.20 (page 8–24) are shown with their vertical edges “detected”
(highlighted) in (B) of Figure 8.20.
When configured as shown in (C) of Figure 8.18, where just three adjacent
vertical boxes have asterisks (they must be the same three vertical boxes for
both
Max and Min ), the effect of the Max – Min function is to “detect” only
the horizontal edges on objects within the inspection window. Thus, the
rectangular black objects shown in (A) of Figure 8.21 (page 8–24) are shown
with their horizontal edges “detected” (highlighted) in (B) of Figure 8.21.