Image Processing Reference
In-Depth Information
Fig. 6.14
Boundary detection
6.4
Further Information
It has been assumed in this chapter that the center of the structuring element is
always located on top of the pixel being processed. This need not be the case and
the position of the structuring element can be off-set in any direction if need may be.
When doing so, please remember to include a procedure in you code that handles
the situation when the structuring element or parts hereof is outside the image.
There exit others and more advanced morphologic operations, including gray-
level morphology, than those presented in this chapter. For inspiration please pick up
a topic focusing on these topics, e.g., [7]. In Fig.
6.15
a few examples are provided.
The first example illustrates the process of
skeletonization
, which is closely related
to
thinning
. The latter can produce 1-pixel thin edges as discussed in the previous
chapter. The other example illustrates the distance transform where the value of a
pixel is the distance to the nearest white pixel in the image.
6.5
Exercises
Exercise 1:
Explain the following concepts: structuring element, hit, fit, erosion,
dilation, opening, closing.
Exercise 2:
How can morphology be used to find the outline (edge) of an object?
Exercise 3:
Find
g(x,y)
=
f(x,y)
⊕
SE
1.
f(x,y)
and
SE
1
are defined in
Fig.
6.16
.
