compactness_xldcompactness_xldcompactness_xldCompactnessXldCompactnessXld (Operator)

Name

compactness_xldcompactness_xldcompactness_xldCompactnessXldCompactnessXld — Shape factor for the compactness of contours or polygons.

Signature

Description

The operator compactness_xldcompactness_xldcompactness_xldCompactnessXldCompactnessXld calculates the compactness of each input contour or polygon in XLDXLDXLDXLDXLD. The input contour or polygon must not intersect itself, otherwise the resulting parameter is not meaningful (Whether the input contour or polygon intersects itself or not can be determined with test_self_intersection_xldtest_self_intersection_xldtest_self_intersection_xldTestSelfIntersectionXldTestSelfIntersectionXld). If the input contour or polygon is not closed it will be closed automatically.

Calculation:

If L is the length and F
the area enclosed by the contour or polygon the shape factor
CompactnessCompactnessCompactnessCompactnesscompactness
is defined as:

                     CompactnessCompactnessCompactnessCompactnesscompactness = L^2 / (4 F pi))

The shape factor CompactnessCompactnessCompactnessCompactnesscompactness of a circle is 1. If the contour or polygon encloses an elongated area CompactnessCompactnessCompactnessCompactnesscompactness is larger than 1. The operator compactness_xldcompactness_xldcompactness_xldCompactnessXldCompactnessXld responds to the course of the contour or polygon (roughness). If more than one contour or polygon is passed, the shape factors are stored in a tuple in the same order as the respective contours or polygons in XLDXLDXLDXLDXLD.

Parallelization

• Multithreading type: reentrant (runs in parallel with non-exclusive operators).
• Multithreading scope: global (may be called from any thread).
• Automatically parallelized on tuple level.

Parameters

Result

The operator compactness_xldcompactness_xldcompactness_xldCompactnessXldCompactnessXld 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>)set_system("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_xldgen_contours_skeleton_xldGenContoursSkeletonXldGenContoursSkeletonXld, edges_sub_pixedges_sub_pixedges_sub_pixEdgesSubPixEdgesSubPix, threshold_sub_pixthreshold_sub_pixthreshold_sub_pixThresholdSubPixThresholdSubPix, gen_contour_polygon_xldgen_contour_polygon_xldgen_contour_polygon_xldGenContourPolygonXldGenContourPolygonXld, test_self_intersection_xldtest_self_intersection_xldtest_self_intersection_xldTestSelfIntersectionXldTestSelfIntersectionXld

Alternatives

circularity_xldcircularity_xldcircularity_xldCircularityXldCircularityXld, convexity_xldconvexity_xldconvexity_xldConvexityXldConvexityXld, eccentricity_xldeccentricity_xldeccentricity_xldEccentricityXldEccentricityXld

See also

area_center_xldarea_center_xldarea_center_xldAreaCenterXldAreaCenterXld, select_shape_xldselect_shape_xldselect_shape_xldSelectShapeXldSelectShapeXld

Module

Foundation