erosion2erosion2Erosion2Erosion2 (Operator)

Name

erosion2erosion2Erosion2Erosion2 — Erode a region (using a reference point).

Signature

erosion2(Region, StructElement : RegionErosion : Row, Column, Iterations : )

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_circleGenCircleGenCircleGenCircle, gen_rectangle1gen_rectangle1GenRectangle1GenRectangle1GenRectangle1, gen_rectangle2gen_rectangle2GenRectangle2GenRectangle2GenRectangle2, gen_ellipsegen_ellipseGenEllipseGenEllipseGenEllipse, draw_regiondraw_regionDrawRegionDrawRegionDrawRegion, gen_region_polygongen_region_polygonGenRegionPolygonGenRegionPolygonGenRegionPolygon, gen_region_pointsgen_region_pointsGenRegionPointsGenRegionPointsGenRegionPoints, etc.

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) → object

Regions to be eroded.

StructElementStructElementStructElementStructElementstructElement (input_object) region → object

Structuring element.

RegionErosionRegionErosionRegionErosionRegionErosionregionErosion (output_object) region(-array) → object

Eroded regions.

RowRowRowRowrow (input_control) point.y → (integer)

Row coordinate of the reference point.

Default value: 0

Typical range of values: 0 ≤ Row Row Row Row row ≤ 511 (lin)

Minimum increment: 1

Recommended increment: 1

ColumnColumnColumnColumncolumn (input_control) point.x → (integer)

Column coordinate of the reference point.

Default value: 0

Typical range of values: 0 ≤ Column Column Column Column column ≤ 511 (lin)

Minimum increment: 1

Recommended increment: 1

IterationsIterationsIterationsIterationsiterations (input_control) integer → (integer)

Number of iterations.

Default value: 1

Suggested values: 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 12, 15, 17, 20, 30, 40, 50

Typical range of values: 1 ≤ Iterations Iterations Iterations Iterations 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:

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.