Name
eccentricity_xldeccentricity_xldEccentricityXldeccentricity_xldEccentricityXldEccentricityXld — Shape features derived from the ellipse parameters of contours or polygons.
The operator eccentricity_xldeccentricity_xldEccentricityXldeccentricity_xldEccentricityXldEccentricityXld calculates the three shape
features AnisometryAnisometryAnisometryAnisometryAnisometryanisometry, BulkinessBulkinessBulkinessBulkinessBulkinessbulkiness, and
StructureFactorStructureFactorStructureFactorStructureFactorStructureFactorstructureFactor derived from the geometric moments for each input
contour or polygon. If the
input contour or polygon is not closed it will be closed automatically.
Calculation:
If the ellipse radii Ra, Rb (see elliptic_axis_xldelliptic_axis_xldEllipticAxisXldelliptic_axis_xldEllipticAxisXldEllipticAxisXld)
and the enclosed area A of the contour or polygon are given,
the following applies:
AnisometryAnisometryAnisometryAnisometryAnisometryanisometry = Ra / Rb
BulkinessBulkinessBulkinessBulkinessBulkinessbulkiness = pi Ra Rb / A
StructureFactorStructureFactorStructureFactorStructureFactorStructureFactorstructureFactor = AnisometryAnisometryAnisometryAnisometryAnisometryanisometry * BulkinessBulkinessBulkinessBulkinessBulkinessbulkiness - 1
The anisometry of a circle is 1.0.
It should be noted that eccentricity_xldeccentricity_xldEccentricityXldeccentricity_xldEccentricityXldEccentricityXld only returns useful
results if the contour or polygon encloses a region in the plane. In
particular, the contour or polygon must not intersect itself. This
is particularly important if open contours or polygons are passed
because they are closed automatically, which can produce a
self-intersection. To test whether the contours or polygons
intersect themselves, test_self_intersection_xldtest_self_intersection_xldTestSelfIntersectionXldtest_self_intersection_xldTestSelfIntersectionXldTestSelfIntersectionXld can be
used. If the contour or polygon intersects itself, a useful value
for the anisometry can be calculated with
eccentricity_points_xldeccentricity_points_xldEccentricityPointsXldeccentricity_points_xldEccentricityPointsXldEccentricityPointsXld.
If more than one contour is passed the results are stored in tuples,
the index of a value in the tuple corresponding to the index of a
contour in the input.
- 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.
Anisometry of the contours or polygons.
Assertion: Anisometry >= 1.0
Bulkiness of the contours or polygons.
Structure factor of the contours or polygons.
The operator eccentricity_xldeccentricity_xldEccentricityXldeccentricity_xldEccentricityXldEccentricityXld 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>)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_xldgen_contours_skeleton_xldGenContoursSkeletonXldgen_contours_skeleton_xldGenContoursSkeletonXldGenContoursSkeletonXld,
edges_sub_pixedges_sub_pixEdgesSubPixedges_sub_pixEdgesSubPixEdgesSubPix,
threshold_sub_pixthreshold_sub_pixThresholdSubPixthreshold_sub_pixThresholdSubPixThresholdSubPix,
gen_contour_polygon_xldgen_contour_polygon_xldGenContourPolygonXldgen_contour_polygon_xldGenContourPolygonXldGenContourPolygonXld,
test_self_intersection_xldtest_self_intersection_xldTestSelfIntersectionXldtest_self_intersection_xldTestSelfIntersectionXldTestSelfIntersectionXld
eccentricity_points_xldeccentricity_points_xldEccentricityPointsXldeccentricity_points_xldEccentricityPointsXldEccentricityPointsXld
elliptic_axis_xldelliptic_axis_xldEllipticAxisXldelliptic_axis_xldEllipticAxisXldEllipticAxisXld,
moments_region_2ndmoments_region_2ndMomentsRegion2ndmoments_region_2ndMomentsRegion2ndMomentsRegion2nd,
select_shape_xldselect_shape_xldSelectShapeXldselect_shape_xldSelectShapeXldSelectShapeXld,
area_center_xldarea_center_xldAreaCenterXldarea_center_xldAreaCenterXldAreaCenterXld
Foundation