dilation2Dilation2Dilation2dilation2dilation2🔗

Short description🔗

dilation2Dilation2Dilation2dilation2dilation2 — Dilate a region (using a reference point).

Signature🔗

dilation2( region Region, region StructElement, out region RegionDilation, point.y Row, point.x Column, integer Iterations )

Description🔗

dilation2Dilation2 dilates the input regions with a structuring element (StructElementstructElementstruct_element) having the reference point (Rowrowrow,Columncolumncolumn). dilation2Dilation2 has a similar effect as dilation1Dilation1, the difference is that the reference point of the structuring element can be chosen arbitrarily. The parameter Iterationsiterationsiterations 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 \(n\).

An empty region is generated in case of an empty structuring element.

Structuring elements (StructElementstructElementstruct_element) can be generated with operators such as gen_circleGenCircle, gen_rectangle1GenRectangle1, gen_rectangle2GenRectangle2, gen_ellipseGenEllipse, draw_regionDrawRegion, gen_region_polygonGenRegionPolygon, gen_region_pointsGenRegionPoints, etc.

Attention🔗

A dilation always results in enlarged regions. Closely spaced regions which may touch or overlap as a result of the dilation are still treated as two separate regions. If the desired behavior is to merge them into one region, the operator union1Union1 has to be called first.

Execution information🔗

Execution information

Multithreading type: reentrant (runs in parallel with non-exclusive operators).
Multithreading scope: global (may be called from any thread).

Parameters🔗

Regionregionregion (input_object) region(-array) → objectHObjectHRegionHObjectHobject

Regions to be dilated.

StructElementstructElementstruct_element (input_object) region → objectHObjectHRegionHObjectHobject

Structuring element.

RegionDilationregionDilationregion_dilation (output_object) region(-array) → objectHObjectHRegionHObjectHobject *

Dilated regions.

Rowrowrow (input_control) point.y → (integer)HTuple (Hlong)HTuple (int / long)intHtuple (Hlong)

Row coordinate of the reference point.

Default: 00

Columncolumncolumn (input_control) point.x → (integer)HTuple (Hlong)HTuple (int / long)intHtuple (Hlong)

Column coordinate of the reference point.

Default: 00

Iterationsiterationsiterations (input_control) integer → (integer)HTuple (Hlong)HTuple (int / long)intHtuple (Hlong)

Number of iterations.

Default: 11
Suggested values: 1, 2, 3, 4, 5, 7, 11, 17, 25, 32, 64, 128
Value range: 1 ≤ Iterations (lin)
Minimum increment: 1
Recommended increment: 1

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:

\[\begin{eqnarray*} O(\sqrt{F1} \cdot \sqrt{F2} \cdot \textrm{Iterations}) \enspace . \end{eqnarray*}\]

Result🔗

dilation2Dilation2 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.

Combinations with other operators🔗

Combinations

Possible predecessors

thresholdThreshold, regiongrowingRegiongrowing, connectionConnection, union1Union1, watershedsWatersheds, class_ndim_normClassNdimNorm, gen_circleGenCircle, gen_ellipseGenEllipse, gen_rectangle1GenRectangle1, gen_rectangle2GenRectangle2, draw_regionDrawRegion, gen_region_pointsGenRegionPoints, gen_region_polygon_filledGenRegionPolygonFilled

Possible successors

reduce_domainReduceDomain, add_channelsAddChannels, select_shapeSelectShape, area_centerAreaCenter, connectionConnection

Alternatives

minkowski_add1MinkowskiAdd1, minkowski_add2MinkowskiAdd2, dilation1Dilation1

Module🔗

Foundation