dilation2 ( Region, StructElement : RegionDilation : Row, Column, Iterations : )

Dilate a region (using a reference point).

dilation2 dilates the input regions with a structuring element (StructElement) having the reference point (Row,Column). dilation2 has a similar effect as dilation1, the difference being that the reference point of the structuring element can be chosen arbitrarily. The parameter Iterations 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 (StructElement) can be generated with operators such as circle, rectangle1, rectangle2, ellipse, draw_region, store_polygon, store_coord, etc.


Attention

A dilation always results in the regions being enlarged. Closely spaced regions which may touch or overlap as a result of the dilation are still treated as two separate regions. If the desired behaviour is to merge them into one region, the operator union1 has to be called first.


Parameters

Region (input_object)
region(-array) -> object
Regions to be dilated.

StructElement (input_object)
region -> object
Structuring element.

RegionDilation (output_object)
region(-array) -> object
Dilated regions.

Row (input_control)
point.y -> integer
Row coordinate of the reference point.
Default value: 0

Column (input_control)
point.x -> integer
Column coordinate of the reference point.
Default value: 0

Iterations (input_control)
integer -> integer
Number of iterations.
Default value: 1
Suggested values: 1, 2, 3, 4, 5, 7, 11, 17, 25, 32, 64, 128
Range of values: 1 <= Iterations
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. The the runtime complexity for one region is:

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


Result

dilation2 returns TRUE if all parameters are correct. The behavior in case of empty or no input region can be set via:

  a) no region:    set_system(::'no_object_result',<RegionResult>:)
  b) empty region: set_system(::'empty_region_result',<RegionResult>:)
Otherwise, an exception is raised.


Possible Predecessors

threshold__, regiongrowing__, connection, union1, watersheds, class_ndim1__, circle, ellipse, rectangle1, rectangle2, draw_region, store_coord, struct_elements, store_filled_polygon


Possible Successors

reduce_domain, add_channels, select_shape, area_center, connection


Alternatives

minkowski_add1, minkowski_add2, dilation1, dilation_golay, dilation_seq


See also

erosion1, erosion2, opening, closing



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