ClassesClasses | | Operators

eccentricity_points_xldeccentricity_points_xldEccentricityPointsXldEccentricityPointsXld (Operator)

Name

eccentricity_points_xldeccentricity_points_xldEccentricityPointsXldEccentricityPointsXld — Anisometry of contours or polygons treated as point clouds.

Signature

eccentricity_points_xld(XLD : : : Anisometry)

Herror eccentricity_points_xld(const Hobject XLD, double* Anisometry)

Herror T_eccentricity_points_xld(const Hobject XLD, Htuple* Anisometry)

void EccentricityPointsXld(const HObject& XLD, HTuple* Anisometry)

HTuple HXLD::EccentricityPointsXld() const

static void HOperatorSet.EccentricityPointsXld(HObject XLD, out HTuple anisometry)

HTuple HXLD.EccentricityPointsXld()

Description

The operator eccentricity_points_xldeccentricity_points_xldEccentricityPointsXldEccentricityPointsXldEccentricityPointsXld calculates the shape feature AnisometryAnisometryAnisometryAnisometryanisometry derived from the geometric moments of the point cloud given by the contour or polygon XLDXLDXLDXLDXLD (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.

Calculation: If the ellipse radii Ra, Rb (elliptic_axis_points_xldelliptic_axis_points_xldEllipticAxisPointsXldEllipticAxisPointsXldEllipticAxisPointsXld) are given, the following applies:

The anisometry of a circle is 1.0.

eccentricity_points_xldeccentricity_points_xldEccentricityPointsXldEccentricityPointsXldEccentricityPointsXld should be used if the contour XLDXLDXLDXLDXLD 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_xldeccentricity_xldEccentricityXldEccentricityXldEccentricityXld does not produce useful results. To test whether the contours or polygons intersect themselves, test_self_intersection_xldtest_self_intersection_xldTestSelfIntersectionXldTestSelfIntersectionXldTestSelfIntersectionXld 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 polygons in XLDXLDXLDXLDXLD.

Execution Information

Parameters

XLDXLDXLDXLDXLD (input_object)  xld(-array) objectHXLDHXLDHobject

Contours or polygons to be examined.

AnisometryAnisometryAnisometryAnisometryanisometry (output_control)  real(-array) HTupleHTupleHtuple (real) (double) (double) (double)

Anisometry of the contours or polygons.

Assertion: Anisometry >= 1.0

Result

The operator eccentricity_points_xldeccentricity_points_xldEccentricityPointsXldEccentricityPointsXldEccentricityPointsXld 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>)set_system("no_object_result",<Result>)SetSystem("no_object_result",<Result>)SetSystem("no_object_result",<Result>)SetSystem("no_object_result",<Result>). If necessary an exception is raised.

Possible Predecessors

gen_contours_skeleton_xldgen_contours_skeleton_xldGenContoursSkeletonXldGenContoursSkeletonXldGenContoursSkeletonXld, edges_sub_pixedges_sub_pixEdgesSubPixEdgesSubPixEdgesSubPix, threshold_sub_pixthreshold_sub_pixThresholdSubPixThresholdSubPixThresholdSubPix, gen_contour_polygon_xldgen_contour_polygon_xldGenContourPolygonXldGenContourPolygonXldGenContourPolygonXld, test_self_intersection_xldtest_self_intersection_xldTestSelfIntersectionXldTestSelfIntersectionXldTestSelfIntersectionXld

Alternatives

eccentricity_xldeccentricity_xldEccentricityXldEccentricityXldEccentricityXld

See also

elliptic_axis_points_xldelliptic_axis_points_xldEllipticAxisPointsXldEllipticAxisPointsXldEllipticAxisPointsXld, moments_region_2ndmoments_region_2ndMomentsRegion2ndMomentsRegion2ndMomentsRegion2nd, select_shape_xldselect_shape_xldSelectShapeXldSelectShapeXldSelectShapeXld

Module

Foundation


ClassesClasses | | Operators