Morphological Closing of a Window
Perform morphological closing of a window
closing.owin(w, r, ...)
- A window (object of class
- positive number: the radius of the closing.
- extra arguments passed to
as.maskcontrolling the pixel resolution
The morphological closing (Serra, 1982) of a set $W$ by a distance $r > 0$ is the set of all points that cannot be separated from $W$ by any circle of radius $r$. That is, a point $x$ belongs to the closing $W*$ if it is impossible to draw any circle of radius $r$ that has $x$ on the inside and $W$ on the outside. The closing $W*$ contains the original set $W$.
For a small radius $r$, the closing operation has the effect of smoothing out irregularities in the boundary of $W$. For larger radii, the closing operation smooths out concave features in the boundary. For very large radii, the closed set $W*$ becomes more and more convex.
This function computes the closing of the window
as a binary pixel mask. If
w is not already a mask, it is first
converted to a mask by
as.mask. The arguments
"..." determine the pixel resolution. There is a sensible
- Another object of class
"owin"representing the closed window.
Serra, J. (1982) Image analysis and mathematical morphology. Academic Press.
opening.owin for the opposite operation.
data(letterR) v <- closing.owin(letterR, 0.25, dimyx=256) plot(v, main="closing.owin") plot(letterR, add=TRUE)