gen_contours_skeleton_xldgen_contours_skeleton_xldGenContoursSkeletonXldGenContoursSkeletonXld (Operator)


gen_contours_skeleton_xldgen_contours_skeleton_xldGenContoursSkeletonXldGenContoursSkeletonXld — Convert a skeleton into XLD contours.


gen_contours_skeleton_xld(Skeleton : Contours : Length, Mode : )

Herror gen_contours_skeleton_xld(const Hobject Skeleton, Hobject* Contours, const Hlong Length, const char* Mode)

Herror T_gen_contours_skeleton_xld(const Hobject Skeleton, Hobject* Contours, const Htuple Length, const Htuple Mode)

void GenContoursSkeletonXld(const HObject& Skeleton, HObject* Contours, const HTuple& Length, const HTuple& Mode)

HXLDCont HRegion::GenContoursSkeletonXld(Hlong Length, const HString& Mode) const

HXLDCont HRegion::GenContoursSkeletonXld(Hlong Length, const char* Mode) const

HXLDCont HRegion::GenContoursSkeletonXld(Hlong Length, const wchar_t* Mode) const   (Windows only)

static void HOperatorSet.GenContoursSkeletonXld(HObject skeleton, out HObject contours, HTuple length, HTuple mode)

HXLDCont HRegion.GenContoursSkeletonXld(int length, string mode)


gen_contours_skeleton_xldgen_contours_skeleton_xldGenContoursSkeletonXldGenContoursSkeletonXldGenContoursSkeletonXld converts the input skeleton (e.g., edges) SkeletonSkeletonSkeletonSkeletonskeleton, which is assumed to contain mostly one pixel wide regions (see skeletonskeletonSkeletonSkeletonSkeleton), into XLD contours.

The algorithm first attempts to transform the regions to contain only line segments in 8-neighborhood. In a second step, the junction points are labeled. After this, gen_contours_skeleton_xldgen_contours_skeleton_xldGenContoursSkeletonXldGenContoursSkeletonXldGenContoursSkeletonXld tries to generate contours which end in junction or end points, in particular for junction points of the following configurations (in all four possible rotations): 1 0 1 1 0 1 1 0 0 1 0 0 0 1 0 0 1 0 0 2 0 0 2 0 0 2 1 0 2 1 0 2 1 1 2 1 0 0 1 1 0 1 0 1 0 1 0 0 0 1 0 0 1 0 where 0 = background, 1 = foreground, and 2 = junction point.

After this, all contours having at least LengthLengthLengthLengthlength points are returned. Since contours are split at junction points, possibly long contours may be split into several short segments because of short adjacent lines, even if they are longer than LengthLengthLengthLengthlength points, if ModeModeModeModemode = 'filter' was selected. This can be avoided by setting ModeModeModeModemode = 'generalize1'. In this case, the contours are generated as if the segments shorter than LengthLengthLengthLengthlength were not contained in the input region. In order to preserve line segments, which are split into very short segments by the crossing of short lines, ModeModeModeModemode = 'generalize2' can be selected. In this case, line segments are preserved if they end in two junction points, even if they are shorter than LengthLengthLengthLengthlength.

Execution Information


SkeletonSkeletonSkeletonSkeletonskeleton (input_object)  region objectHRegionHRegionHobject

Skeleton of which the contours are to be determined.

ContoursContoursContoursContourscontours (output_object)  xld_cont-array objectHXLDContHXLDContHobject *

Resulting contours.

LengthLengthLengthLengthlength (input_control)  integer HTupleHTupleHtuple (integer) (int / long) (Hlong) (Hlong)

Minimum number of points a contour has to have.

Default value: 1

Suggested values: 1, 2, 3, 5, 10, 20

ModeModeModeModemode (input_control)  string HTupleHTupleHtuple (string) (string) (HString) (char*)

Contour filter mode.

Default value: 'filter' "filter" "filter" "filter" "filter"

List of values: 'filter'"filter""filter""filter""filter", 'generalize1'"generalize1""generalize1""generalize1""generalize1", 'generalize2'"generalize2""generalize2""generalize2""generalize2"

Possible Predecessors


Possible Successors

smooth_contours_xldsmooth_contours_xldSmoothContoursXldSmoothContoursXldSmoothContoursXld, get_contour_xldget_contour_xldGetContourXldGetContourXldGetContourXld, gen_polygons_xldgen_polygons_xldGenPolygonsXldGenPolygonsXldGenPolygonsXld

See also

edges_imageedges_imageEdgesImageEdgesImageEdgesImage, thresholdthresholdThresholdThresholdThreshold, get_region_contourget_region_contourGetRegionContourGetRegionContourGetRegionContour