Operators

# dilation_seq (Operator)

## Name

dilation_seq — Dilate a region sequentially.

## Signature

dilation_seq(Region : RegionDilation : GolayElement, Iterations : )

## Description

dilation_seq computes the sequential dilation of the input region Region with the selected structuring element GolayElement from the Golay alphabet. This is done by executing the operator dilation_golay with all rotations of the structuring element Iterations times. The following structuring elements can be selected:

'l', 'd', 'c', 'f', 'h', 'k'.

In order to compute the skeleton of a region, usually the elements 'l' and 'm' are used. Only the “foreground elements” (even rotation numbers) are used. The elements 'i' and 'e' result in unchanged output regions. The elements 'l', 'm' and 'f2' are identical for the foreground. The Golay elements, together with all possible rotations, are described with the operator golay_elements.

## Parallelization

• Multithreading type: reentrant (runs in parallel with non-exclusive operators).
• Automatically parallelized on tuple level.

## Parameters

Region (input_object)  region(-array) object

Regions to be dilated.

RegionDilation (output_object)  region(-array) object

Dilated regions.

GolayElement (input_control)  string (string)

Structuring element from the Golay alphabet.

Default value: 'h'

List of values: 'c', 'd', 'f', 'h', 'k', 'l'

Iterations (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 (lin)

Minimum increment: 1

Recommended increment: 1

## Complexity

Let F be the area of an input region. Then the runtime complexity for one region is:

## Result

dilation_seq 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.