erosion2erosion2erosion2Erosion2Erosion2 (Operator)

Name

erosion2erosion2erosion2Erosion2Erosion2 — Erode a region (using a reference point).

Signature

Description

erosion2erosion2erosion2Erosion2Erosion2 erodes the input regions with a structuring element (StructElementStructElementStructElementStructElementstructElement) having the reference point (RowRowRowRowrow,ColumnColumnColumnColumncolumn). erosion2erosion2erosion2Erosion2Erosion2 has a similar effect as erosion1erosion1erosion1Erosion1Erosion1, the difference is that the reference point of the structuring element can be chosen arbitrarily. The parameter IterationsIterationsIterationsIterationsiterations determines the number of iterations which are to be performed with the structuring element. The result of iteration n-1 is used as input for iteration n.

A maximum region is generated in case of an empty structuring element.

Structuring elements (StructElementStructElementStructElementStructElementstructElement) can be generated with operators such as gen_circlegen_circlegen_circleGenCircleGenCircle, gen_rectangle1gen_rectangle1gen_rectangle1GenRectangle1GenRectangle1, gen_rectangle2gen_rectangle2gen_rectangle2GenRectangle2GenRectangle2, gen_ellipsegen_ellipsegen_ellipseGenEllipseGenEllipse, draw_regiondraw_regiondraw_regionDrawRegionDrawRegion, gen_region_polygongen_region_polygongen_region_polygonGenRegionPolygonGenRegionPolygon, gen_region_pointsgen_region_pointsgen_region_pointsGenRegionPointsGenRegionPoints, etc.

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 F1 be the area of the input region, and F2 be the area of the structuring element. Then the runtime complexity for one region is:

    O(sqrt(F1) * sqrt(F2) * Iterations) .

Result

erosion2erosion2erosion2Erosion2Erosion2 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

thresholdthresholdthresholdThresholdThreshold, regiongrowingregiongrowingregiongrowingRegiongrowingRegiongrowing, watershedswatershedswatershedsWatershedsWatersheds, class_ndim_normclass_ndim_normclass_ndim_normClassNdimNormClassNdimNorm, gen_circlegen_circlegen_circleGenCircleGenCircle, gen_ellipsegen_ellipsegen_ellipseGenEllipseGenEllipse, gen_rectangle1gen_rectangle1gen_rectangle1GenRectangle1GenRectangle1, gen_rectangle2gen_rectangle2gen_rectangle2GenRectangle2GenRectangle2, draw_regiondraw_regiondraw_regionDrawRegionDrawRegion, gen_region_pointsgen_region_pointsgen_region_pointsGenRegionPointsGenRegionPoints, gen_struct_elementsgen_struct_elementsgen_struct_elementsGenStructElementsGenStructElements, gen_region_polygon_filledgen_region_polygon_filledgen_region_polygon_filledGenRegionPolygonFilledGenRegionPolygonFilled

Possible Successors

reduce_domainreduce_domainreduce_domainReduceDomainReduceDomain, select_shapeselect_shapeselect_shapeSelectShapeSelectShape, area_centerarea_centerarea_centerAreaCenterAreaCenter, connectionconnectionconnectionConnectionConnection

Alternatives

minkowski_sub2minkowski_sub2minkowski_sub2MinkowskiSub2MinkowskiSub2, minkowski_sub1minkowski_sub1minkowski_sub1MinkowskiSub1MinkowskiSub1, erosion1erosion1erosion1Erosion1Erosion1, erosion_golayerosion_golayerosion_golayErosionGolayErosionGolay, erosion_seqerosion_seqerosion_seqErosionSeqErosionSeq

See also

transpose_regiontranspose_regiontranspose_regionTransposeRegionTransposeRegion, gen_circlegen_circlegen_circleGenCircleGenCircle, gen_rectangle2gen_rectangle2gen_rectangle2GenRectangle2GenRectangle2, gen_region_polygongen_region_polygongen_region_polygonGenRegionPolygonGenRegionPolygon

Module

Foundation