Rockwell Automation 5370-CVIM2 Module - Manual (Page 246)

Chapter 7
Inspection Tools
7–8
Figure 7.5 Examples: Counting Black Pixels and White Pixels Across a Workpiece
A
B
Foreground Objects; Background Objects
These two gage operations are available with both gaging modes. The object
counting operations count the total number of “foreground” or “background”
objects along the length of the gage.
In the context of gage operations, the terms “foreground” and “background”
have specific, and different, meanings for the binary gaging mode and the
gray scale gaging modes. These are described in the following sections.
Binary Gaging Mode: Foreground Objects
Foreground objects are those objects containing white pixels that lie
completely between the first and last detected edges on the axis. In example
(A) of Figure 7.6 (page 7–9), the four foreground (white) objects
correspond to the four white spaces between the black rectangles. Note that
the white areas at each end of the gage do not qualify as foreground objects,
since they are outside the first and last detected edges on the gage.