Rockwell Automation 5370-CVIM2 Module - Manual (Page 456)

5 Chapter Chapter 8
Thresholds, Filters, and Morphology
8–17
Figure 8.14 Binary Morph Function Selection Panel
NOTE: Use the scroll bar to access
the entire list of filter functions
Here are the binary morphology filter functions available in the Binary
Morph selection menu, along with a brief description of each:
•
Identity –– This function performs no filtering effect on the binary
image. It is equivalent to making the stage inactive. Thus, when all six
menu boxes are set to
Identity , the binary image is unaffected by the
morphology processor.
•
Smoothing –– This function performs a filtering operation that removes
”noise” pixels from the image. Noise pixels are isolated single or double
black pixels on a white background or white pixels on a black
background. “Smoothing” also smoothes edges on an object, rounds sharp
corners, and removes small features from the object and image field. It
does this without affecting the area of large objects.
•
Inversion –– This function changes all white pixels to black pixels, and
vice versa; thus, it inverts the image.
•
Erosion –– This function erodes the edges of white objects (and,
conversely, dilates the edges of black objects). Thus, white objects in the
image field get smaller, while black objects get larger. Successive stages
of erosion can be used to achieve the desired effect. If it is necessary to
remove white noise from within a black object without changing the size
of the black object, the stages of erosion must be followed by an equal
number of stages of dilation.
Another effect of erosion is to ”weld” together small black objects that are
otherwise separated in the original image.