is.convex(x)
"owin"
).
TRUE
if x
is convex.
x
is a rectangle, the result is TRUE. If x
is polygonal, the result is TRUE if x
consists of a
single polygon and this polygon is equal to the minimal convex hull
of its vertices computed by chull
.
If x
is a mask, the algorithm first extracts all boundary
pixels of x
using vertices
. Then it computes
the (polygonal) convex hull $K$ of the boundary pixels.
The result is TRUE if every boundary pixel lies within
one pixel diameter of an edge of $K$.
owin
,
convexhull.xy
,
vertices