Name
elliptic_axis_points_xld elliptic_axis_points_xld EllipticAxisPointsXld elliptic_axis_points_xld EllipticAxisPointsXld EllipticAxisPointsXld — Parameters of the equivalent ellipse of contours or polygons treated as
point clouds.
Herror elliptic_axis_points_xld (const Hobject XLD , double* Ra , double* Rb , double* Phi )
Herror T_elliptic_axis_points_xld (const Hobject XLD , Htuple* Ra , Htuple* Rb , Htuple* Phi )
Herror elliptic_axis_points_xld (Hobject XLD , double* Ra , double* Rb , double* Phi )
Herror elliptic_axis_points_xld (Hobject XLD , HTuple* Ra , HTuple* Rb , HTuple* Phi )
double HXLD ::EllipticAxisPointsXld (double* Rb , double* Phi ) const
HTuple HXLDArray ::EllipticAxisPointsXld (HTuple* Rb , HTuple* Phi ) const
void EllipticAxisPointsXld (const HObject& XLD , HTuple* Ra , HTuple* Rb , HTuple* Phi )
HTuple HXLD ::EllipticAxisPointsXld (HTuple* Rb , HTuple* Phi ) const
double HXLD ::EllipticAxisPointsXld (double* Rb , double* Phi ) const
The operator elliptic_axis_points_xld elliptic_axis_points_xld EllipticAxisPointsXld elliptic_axis_points_xld EllipticAxisPointsXld EllipticAxisPointsXld calculates the radii
(Ra Ra Ra Ra Ra ra , Rb Rb Rb Rb Rb rb ) and the orientation (Phi Phi Phi Phi Phi phi , in radians)
of the ellipse
having the same orientation and the same aspect ratio as the point cloud
given by the contour or polygon
XLD XLD XLD XLD XLD 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.
Calculation:
If the moments
,
and
are normalized to the area (see moments_points_xld moments_points_xld MomentsPointsXld moments_points_xld MomentsPointsXld MomentsPointsXld ),
the major radius Ra Ra Ra Ra Ra ra and the minor radius Rb Rb Rb Rb Rb rb are calculated
as:
The orientation Phi Phi Phi Phi Phi phi , i.e., the angle between the major axis
and the x (column) axis, is defined by:
elliptic_axis_points_xld elliptic_axis_points_xld EllipticAxisPointsXld elliptic_axis_points_xld EllipticAxisPointsXld EllipticAxisPointsXld should be used if the contour XLD XLD XLD XLD XLD XLD
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
elliptic_axis_xld elliptic_axis_xld EllipticAxisXld elliptic_axis_xld EllipticAxisXld EllipticAxisXld does not produce useful results. To test whether
the contours or polygons intersect themselves,
test_self_intersection_xld test_self_intersection_xld TestSelfIntersectionXld test_self_intersection_xld TestSelfIntersectionXld TestSelfIntersectionXld can be used.
If more than one contour or polygon is passed, the results are stored
in tuples in the same order as the respective contours or polygons in
XLD XLD XLD XLD XLD XLD .
Multithreading type: reentrant (runs in parallel with non-exclusive operators).
Multithreading scope: global (may be called from any thread).
Automatically parallelized on tuple level.
Contours or polygons to be examined.
Ra Ra Ra Ra Ra ra (output_control) real(-array) → HTuple HTuple HTuple VARIANT Htuple (real) (double ) (double ) (double ) (double ) (double )
Major radius.
Assertion: Ra >= 0.0
Rb Rb Rb Rb Rb rb (output_control) real(-array) → HTuple HTuple HTuple VARIANT Htuple (real) (double ) (double ) (double ) (double ) (double )
Minor radius.
Assertion: Rb >= 0.0 && Rb <= Ra
Angle between the major axis and the column axis
(radians).
Assertion: - pi / 2 < Phi && Phi <= pi / 2
Let n be the number of points of the contour or polygon.
Then the run time is O(n).
elliptic_axis_points_xld elliptic_axis_points_xld EllipticAxisPointsXld elliptic_axis_points_xld EllipticAxisPointsXld EllipticAxisPointsXld returns 2 (H_MSG_TRUE) if the input is not
empty. If the input is empty the behavior can be set via
set_system(::'no_object_result',<Result>:) set_system("no_object_result",<Result>) SetSystem("no_object_result",<Result>) set_system("no_object_result",<Result>) SetSystem("no_object_result",<Result>) SetSystem("no_object_result",<Result>) . If necessary,
an exception is raised.
gen_contours_skeleton_xld gen_contours_skeleton_xld GenContoursSkeletonXld gen_contours_skeleton_xld GenContoursSkeletonXld GenContoursSkeletonXld ,
edges_sub_pix edges_sub_pix EdgesSubPix edges_sub_pix EdgesSubPix EdgesSubPix ,
threshold_sub_pix threshold_sub_pix ThresholdSubPix threshold_sub_pix ThresholdSubPix ThresholdSubPix ,
gen_contour_polygon_xld gen_contour_polygon_xld GenContourPolygonXld gen_contour_polygon_xld GenContourPolygonXld GenContourPolygonXld ,
test_self_intersection_xld test_self_intersection_xld TestSelfIntersectionXld test_self_intersection_xld TestSelfIntersectionXld TestSelfIntersectionXld
area_center_points_xld area_center_points_xld AreaCenterPointsXld area_center_points_xld AreaCenterPointsXld AreaCenterPointsXld ,
gen_ellipse_contour_xld gen_ellipse_contour_xld GenEllipseContourXld gen_ellipse_contour_xld GenEllipseContourXld GenEllipseContourXld
elliptic_axis_xld elliptic_axis_xld EllipticAxisXld elliptic_axis_xld EllipticAxisXld EllipticAxisXld ,
smallest_rectangle2 smallest_rectangle2 SmallestRectangle2 smallest_rectangle2 SmallestRectangle2 SmallestRectangle2
moments_xld moments_xld MomentsXld moments_xld MomentsXld MomentsXld ,
smallest_circle_xld smallest_circle_xld SmallestCircleXld smallest_circle_xld SmallestCircleXld SmallestCircleXld ,
smallest_rectangle1_xld smallest_rectangle1_xld SmallestRectangle1Xld smallest_rectangle1_xld SmallestRectangle1Xld SmallestRectangle1Xld ,
smallest_rectangle2_xld smallest_rectangle2_xld SmallestRectangle2Xld smallest_rectangle2_xld SmallestRectangle2Xld SmallestRectangle2Xld ,
shape_trans_xld shape_trans_xld ShapeTransXld shape_trans_xld ShapeTransXld ShapeTransXld
R. Haralick, L. Shapiro
“Computer and Robot Vision”
Addison-Wesley, 1992, pp. 73-75
Foundation