This function computes the areas of the erosions of the window
w
by each of the radii r[i]
. The morphological erosion of a set $W$ by a distance $r > 0$
is the subset
consisting of all points $x in W$ such that the
distance from $x$ to the boundary of $W$ is greater than
or equal to $r$. In other words it is the result of trimming
a margin of width $r$ off the set $W$.
The argument r
should be a vector of positive numbers.
The argument w
should be a window (an object of class
"owin"
, see owin.object
for details)
or can be given in any format acceptable to as.owin()
.
Unless w
is a rectangle, the computation is performed
using a pixel raster approximation.
To compute the eroded window itself, use erosion
.