thinning_seqthinning_seqThinningSeqthinning_seqThinningSeqThinningSeq (Operator)

Name

thinning_seqthinning_seqThinningSeqthinning_seqThinningSeqThinningSeq — Remove the result of a hit-or-miss operation from a region (sequential).

Signature

Description

thinning_seqthinning_seqThinningSeqthinning_seqThinningSeqThinningSeq calculates the sequential thinning of the input regions with a structuring element from the Golay alphabet (GolayElementGolayElementGolayElementGolayElementGolayElementgolayElement). To do so, thinning_seqthinning_seqThinningSeqthinning_seqThinningSeqThinningSeq calls the operator thinning_golaythinning_golayThinningGolaythinning_golayThinningGolayThinningGolay with all possible rotations of the structuring element IterationsIterationsIterationsIterationsIterationsiterations times. If IterationsIterationsIterationsIterationsIterationsiterations is chosen large enough, the operator calculates the skeleton of a region if the structuring elements 'l' or 'm' are used. For the element 'c' the background and foreground are exchanged in order to have an effect on the interior boundary of a region. If a very large value or 'maximal' is passed for IterationsIterationsIterationsIterationsIterationsiterations the iteration stops if no more changes occur. The following structuring elements are available:

'l'

Skeleton, similar to skeletonskeletonSkeletonskeletonSkeletonSkeleton. This structuring element is also used in morph_skizmorph_skizMorphSkizmorph_skizMorphSkizMorphSkiz.

'm'

A skeleton with many “hairs” and multiple (parallel) branches.

'd'

A skeleton without multiple branches, but with many gaps, similar to morph_skeletonmorph_skeletonMorphSkeletonmorph_skeletonMorphSkeletonMorphSkeleton.

'c'

Uniform erosion of the region.

'e'

One pixel wide lines are shortened. This structuring element is also used in morph_skizmorph_skizMorphSkizmorph_skizMorphSkizMorphSkiz.

'i'

Isolated points are removed. (Only IterationsIterationsIterationsIterationsIterationsiterations = 1 is useful.)

'f'

Y-junctions are eliminated. (Only IterationsIterationsIterationsIterationsIterationsiterations = 1 is useful.)

'f2'

One pixel long branches and corners are removed. (Only IterationsIterationsIterationsIterationsIterationsiterations = 1 is useful.)

'h'

A kind of inner boundary, which, however, is thicker than the result of boundaryboundaryBoundaryboundaryBoundaryBoundary, is generated. (Only IterationsIterationsIterationsIterationsIterationsiterations = 1 is useful.)

'k'

Junction points are eliminated, but also new ones are generated.

The Golay elements, together with all possible rotations, are described with the operator golay_elementsgolay_elementsGolayElementsgolay_elementsGolayElementsGolayElements.

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

Complexity

Let F be the area of an input region. Then the runtime complexity for one region is:

Result

thinning_seqthinning_seqThinningSeqthinning_seqThinningSeqThinningSeq returns 2 (H_MSG_TRUE) if all parameters are correct. The behavior in case of empty or no input region can be set via:

• no region: set_system('no_object_result',<RegionResult>)

• empty region: set_system('empty_region_result',<RegionResult>)

Otherwise, an exception is raised.

Possible Predecessors

thresholdthresholdThresholdthresholdThresholdThreshold, regiongrowingregiongrowingRegiongrowingregiongrowingRegiongrowingRegiongrowing, connectionconnectionConnectionconnectionConnectionConnection, union1union1Union1union1Union1Union1, watershedswatershedsWatershedswatershedsWatershedsWatersheds, class_ndim_normclass_ndim_normClassNdimNormclass_ndim_normClassNdimNormClassNdimNorm, gen_circlegen_circleGenCirclegen_circleGenCircleGenCircle, gen_ellipsegen_ellipseGenEllipsegen_ellipseGenEllipseGenEllipse, gen_rectangle1gen_rectangle1GenRectangle1gen_rectangle1GenRectangle1GenRectangle1, gen_rectangle2gen_rectangle2GenRectangle2gen_rectangle2GenRectangle2GenRectangle2, draw_regiondraw_regionDrawRegiondraw_regionDrawRegionDrawRegion, gen_region_pointsgen_region_pointsGenRegionPointsgen_region_pointsGenRegionPointsGenRegionPoints, gen_struct_elementsgen_struct_elementsGenStructElementsgen_struct_elementsGenStructElementsGenStructElements, gen_region_polygon_filledgen_region_polygon_filledGenRegionPolygonFilledgen_region_polygon_filledGenRegionPolygonFilledGenRegionPolygonFilled

Possible Successors

pruningpruningPruningpruningPruningPruning, reduce_domainreduce_domainReduceDomainreduce_domainReduceDomainReduceDomain, select_shapeselect_shapeSelectShapeselect_shapeSelectShapeSelectShape, area_centerarea_centerAreaCenterarea_centerAreaCenterAreaCenter, connectionconnectionConnectionconnectionConnectionConnection, complementcomplementComplementcomplementComplementComplement

Alternatives

skeletonskeletonSkeletonskeletonSkeletonSkeleton, morph_skizmorph_skizMorphSkizmorph_skizMorphSkizMorphSkiz, expand_regionexpand_regionExpandRegionexpand_regionExpandRegionExpandRegion

See also

hit_or_miss_seqhit_or_miss_seqHitOrMissSeqhit_or_miss_seqHitOrMissSeqHitOrMissSeq, erosion_golayerosion_golayErosionGolayerosion_golayErosionGolayErosionGolay, differencedifferenceDifferencedifferenceDifferenceDifference, thinning_golaythinning_golayThinningGolaythinning_golayThinningGolayThinningGolay, thinningthinningThinningthinningThinningThinning, thickening_seqthickening_seqThickeningSeqthickening_seqThickeningSeqThickeningSeq

Module

Foundation