Test Whether a Window is Convex
Determines whether a window is convex.
Window (object of class
x is a rectangle, the result is TRUE.
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
x is a mask, the algorithm first extracts all boundary
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 \(K\).
Logical value, equal to
x is convex.