orientation_points_xldorientation_points_xldOrientationPointsXldOrientationPointsXld (Operator)


orientation_points_xldorientation_points_xldOrientationPointsXldOrientationPointsXld — Orientation of contours or polygons treated as point clouds.


orientation_points_xld(XLD : : : Phi)

Herror orientation_points_xld(const Hobject XLD, double* Phi)

Herror T_orientation_points_xld(const Hobject XLD, Htuple* Phi)

void OrientationPointsXld(const HObject& XLD, HTuple* Phi)

HTuple HXLD::OrientationPointsXld() const

static void HOperatorSet.OrientationPointsXld(HObject XLD, out HTuple phi)

HTuple HXLD.OrientationPointsXld()


The operator orientation_points_xldorientation_points_xldOrientationPointsXldOrientationPointsXldOrientationPointsXld calculates the orientation of the point clouds given by the contours or polygons XLDXLDXLDXLDXLD (i.e., the order of the points in the contour or polygon is not taken into account). The orientation Phi is calculated the same way as in elliptic_axis_points_xldelliptic_axis_points_xldEllipticAxisPointsXldEllipticAxisPointsXldEllipticAxisPointsXld. 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.

In addition, the contour point p_{m} with maximum distance to the center of gravity c is calculated. If the angle between the vector and the vector given by Phi is greater than , the value of is added to the angle. If XLDXLDXLDXLDXLD consists of only two points, PhiPhiPhiPhiphi is given by the direction from the first point towards the second point.

orientation_points_xldorientation_points_xldOrientationPointsXldOrientationPointsXldOrientationPointsXld 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 orientation_xldorientation_xldOrientationXldOrientationXldOrientationXld 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 orientations are stored in a tuple in the same order as the respective contours or polygons in XLDXLDXLDXLDXLD.

Execution Information


XLDXLDXLDXLDXLD (input_object)  xld(-array) objectHXLDHXLDHobject

Contours or polygons to be examined.

PhiPhiPhiPhiphi (output_control)  angle.rad(-array) HTupleHTupleHtuple (real) (double) (double) (double)

Orientation of the contours or polygons (radians).

Assertion: - pi < Phi && Phi <= pi

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


orientation_xldorientation_xldOrientationXldOrientationXldOrientationXld, elliptic_axis_points_xldelliptic_axis_points_xldEllipticAxisPointsXldEllipticAxisPointsXldEllipticAxisPointsXld, smallest_rectangle2_xldsmallest_rectangle2_xldSmallestRectangle2XldSmallestRectangle2XldSmallestRectangle2Xld

See also