A Rectilinearity Measurement for Polygons

In this paper we define a function 7g(P) which is defined for any polygon P and which maps a given polygon P into a number from the interval (0, 1]. The number 7g(P) can be used as an estimate of the rectilinearity of P. The mapping 7(P) has the following desirable properties: - any polygon P has the estimated rectilinearity 7(P) which is a number from (0, 1]; - 7(P)=1 if and only if P is a rectilinear polygon, i.e., all interior angles of P belong to the set {,r/2, 3,r/2}; - inf 7(P) = 0, where H denotes the set of all polygons; PCH - a polygon's rectilinearity measure is invariant under similarity trans- formations