eccentricity_points_xld — Anisometry of contours or polygons treated as point clouds.
eccentricity_points_xld calculates the shape
Anisometry derived from the geometric moments of the
point cloud given by the contour or polygon
XLD (i.e., the order
of the points in the contour or polygon is not taken into account). If the
contour or polygon is closed (end point = start point), the end point of
the contour or polygon is not taken into account to avoid that it receives
twice the weight of the other points.
If the ellipse radii Ra, Rb (
given, the following applies:
The anisometry of a circle is 1.0.
eccentricity_points_xld should be used if the contour
intersects itself or if it is not possible to close the contour using a line
from end to start point without self-intersection, because in this case
eccentricity_xld does not produce useful results. To test whether
the contours or polygons intersect themselves,
test_self_intersection_xld can be used.
If more than one contour or polygon is passed, the values of the anisometry
are stored in a tuple in the same order as the respective contours or
Contours or polygons to be examined.
Anisometry of the contours or polygons.
Anisometry >= 1.0
eccentricity_points_xld returns the value 2 (H_MSG_TRUE)
if the input is not empty. The behavior in case of empty input (no
input contours available) is set via the operator
set_system('no_object_result',<Result>). If necessary an
exception is raised.