compactness_xld — Shape factor for the compactness of contours or polygons.
The operator compactness_xld calculates the compactness of each input contour or polygon in XLD. 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_xld). If the input contour or polygon is not closed it will be closed automatically.
If L is the length and F the area enclosed by the contour or polygon the shape factor Compactness is defined as: Compactness = L^2 / (4 F pi))
The shape factor Compactness of a circle is 1. If the contour or polygon encloses an elongated area Compactness is larger than 1. The operator compactness_xld 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 XLD.
Contours or polygons to be examined.
Compactness of the input contours or polygons.
Assertion: Compactness >= 1.0 || Compactness == 0
The operator compactness_xld 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>). If necessary an exception is raised.
gen_contours_skeleton_xld, edges_sub_pix, threshold_sub_pix, gen_contour_polygon_xld, test_self_intersection_xld
circularity_xld, convexity_xld, eccentricity_xld