Rockwell Automation 5370-CVIM2 Module - Manual (Page 401)

5 Chapter Chapter 7
Inspection Tools
7–163
The Filter selection panel lists eight morphology filtering functions and a
“size” selection field. Morphology is an image processing technique that
evaluates a neighborhood of pixels with the object of adjusting or changing
an individual pixel’s gray scale value on the basis of the gray scale values of
its neighbors.
Here is a brief description of each morphology filter function:
•
None –– This selects no morphology filter function.
•
Smoothing –– This function “smoothes” edges and rounds sharp corners
in the profile image without affecting the larger shapes or contours of the
image. Its performance is similar to a gray scale average function.
•
Erosion –– This function “erodes” the foreground objects (and,
conversely, expands the background objects). The result is that
foreground objects in the profile image get narrower, while background
objects get wider. Its performance is similar to a gray scale “Min”
function.
Erosion has the opposite effect of dilation.
•
Dilation –– This function “dilates” the foreground objects (and,
conversely, shrinks the background objects). The result is that background
objects in the profile image get narrower, while foreground objects get
wider. Its performance is similar to a gray scale “max” function.
Dilation has the opposite effect of erosion.
•
Opening –– This function operates as an erosion followed by a dilation.
The result is that small foreground objects can be eliminated without
affecting the size of background objects. Its performance is similar to a
gray scale “min” followed by a “max.”
Opening has the opposite effect of closing.
•
Closing –– This function operates as a dilation followed by an erosion.
The result is that small background objects can be eliminated without
affecting the size of foreground objects. Its performance is similar to a
gray scale “max” followed by a “min.”
Closing has the opposite effect of opening.
•
Well –– This function performs a closing, then subtracts the original
profile image from the closed image. This allows the profile tool to filter
out large background objects and retain only small background objects
for analysis.
Well has the opposite effect of hat.
•
Hat –– This function performs an opening, then subtracts the original
profile image from the opened image. This allows the profile tool to filter
out large foreground objects and retain only small foreground objects for
analysis.
Hat has the opposite effect of well.
•
Gradient –– This function subtracts the minimum gray scale value in the
morphology neighborhood from the maximum gray scale value in the
neighborhood. The result is a profile image with the “edges” enhanced.