Operator Reference

HALCON Operator Reference / Morphology / Region
ClassesClasses | | Operators

erosion_rectangle1erosion_rectangle1ErosionRectangle1ErosionRectangle1erosion_rectangle1 (Operator)

erosion_rectangle1erosion_rectangle1ErosionRectangle1ErosionRectangle1erosion_rectangle1 — Erode a region with a rectangular structuring element.

Signature

erosion_rectangle1(Region : RegionErosion : Width, Height : )

Herror erosion_rectangle1(const Hobject Region, Hobject* RegionErosion, const Hlong Width, const Hlong Height)

Herror T_erosion_rectangle1(const Hobject Region, Hobject* RegionErosion, const Htuple Width, const Htuple Height)

void ErosionRectangle1(const HObject& Region, HObject* RegionErosion, const HTuple& Width, const HTuple& Height)

HRegion HRegion::ErosionRectangle1(Hlong Width, Hlong Height) const

static void HOperatorSet.ErosionRectangle1(HObject region, out HObject regionErosion, HTuple width, HTuple height)

HRegion HRegion.ErosionRectangle1(int width, int height)

def erosion_rectangle1(region: HObject, width: int, height: int) -> HObject

Description

erosion_rectangle1erosion_rectangle1ErosionRectangle1ErosionRectangle1erosion_rectangle1 applies an erosion with a rectangular structuring element to the input regions RegionRegionRegionregionregion. The size of the structuring rectangle is WidthWidthWidthwidthwidth x HeightHeightHeightheightheight. The operator results in reduced regions, and the areas smaller than the rectangular mask are eliminated.

erosion_rectangle1erosion_rectangle1ErosionRectangle1ErosionRectangle1erosion_rectangle1 is a very fast operation because the height of the rectangle enters only logarithmically into the runtime complexity, while the width does not enter at all. This leads to excellent runtime efficiency, even in the case of very large rectangles (edge length > 100).

Regions containing small connecting strips between large areas are separated only seemingly. They remain logically one region.

Attention

To reduce a region by the same amount in all directions, WidthWidthWidthwidthwidth and HeightHeightHeightheightheight must be odd. If this is not the case, the region is eroded by a smaller amount at the right or at the bottom, respectively, than at the left or at the top.

Execution Information

  • 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

RegionRegionRegionregionregion (input_object)  region(-array) → objectHRegionHObjectHObjectHobject

Regions to be eroded.

RegionErosionRegionErosionRegionErosionregionErosionregion_erosion (output_object)  region(-array) → objectHRegionHObjectHObjectHobject *

Eroded regions.

WidthWidthWidthwidthwidth (input_control)  extent.x → HTupleintHTupleHtuple (integer) (int / long) (Hlong) (Hlong)

Width of the structuring rectangle.

Default: 11

Suggested values: 1, 2, 3, 4, 5, 11, 15, 21, 31, 51, 71, 101, 151, 201

Value range: 1 ≤ Width Width Width width width ≤ 511 (lin)

Minimum increment: 1

Recommended increment: 1

HeightHeightHeightheightheight (input_control)  extent.y → HTupleintHTupleHtuple (integer) (int / long) (Hlong) (Hlong)

Height of the structuring rectangle.

Default: 11

Suggested values: 1, 2, 3, 4, 5, 11, 15, 21, 31, 51, 71, 101, 151, 201

Value range: 1 ≤ Height Height Height height height ≤ 511 (lin)

Minimum increment: 1

Recommended increment: 1

Complexity

Let F1 be the area of an input region and H be the height of the rectangle. Then the runtime complexity for one region is:

Result

erosion_rectangle1erosion_rectangle1ErosionRectangle1ErosionRectangle1erosion_rectangle1 returns 2 ( H_MSG_TRUE) if all parameters are correct. The behavior in case of empty or no input region can be set via:

Otherwise, an exception is raised.

Possible Predecessors

thresholdthresholdThresholdThresholdthreshold, regiongrowingregiongrowingRegiongrowingRegiongrowingregiongrowing, watershedswatershedsWatershedsWatershedswatersheds, class_ndim_normclass_ndim_normClassNdimNormClassNdimNormclass_ndim_norm

Possible Successors

reduce_domainreduce_domainReduceDomainReduceDomainreduce_domain, select_shapeselect_shapeSelectShapeSelectShapeselect_shape, area_centerarea_centerAreaCenterAreaCenterarea_center, connectionconnectionConnectionConnectionconnection

Alternatives

erosion1erosion1Erosion1Erosion1erosion1, minkowski_sub1minkowski_sub1MinkowskiSub1MinkowskiSub1minkowski_sub1

See also

gen_rectangle1gen_rectangle1GenRectangle1GenRectangle1gen_rectangle1

Module

Foundation

ClassesClasses | | Operators