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# SplitRegionIntoComponents

Header: | AVL.h |
---|---|

Namespace: | avl |

Module: | FoundationBasic |

Splits a region into an array of regions. Operates by merging blobs in accordance to the inMaxDistance parameter.

### Syntax

C++

C#

void avl::SplitRegionIntoComponents ( const avl::Region& inRegion, atl::Optional<int> inMaxDistance, float inDistanceBalance, atl::Optional<float> inMaxJointDiameter, atl::Optional<int> inMaxJointWidth, atl::Optional<int> inMaxJointHeight, const int inMinComponentArea, atl::Optional<int> inMaxComponentArea, bool inRemoveBoundaryBlobs, atl::Array<avl::Region>& outComponents )

### Parameters

Name | Type | Range | Default | Description | |
---|---|---|---|---|---|

inRegion | const Region& | Input region | |||

inMaxDistance | Optional<int> | 0 - | 5 | ||

inDistanceBalance | float | -1.0 - 1.0 | Defines how much important the distance between regions in x coordinate is according to distance in y coordinate | ||

inMaxJointDiameter | Optional<float> | 0.0 - | NIL | ||

inMaxJointWidth | Optional<int> | 0 - | NIL | ||

inMaxJointHeight | Optional<int> | 0 - | NIL | ||

inMinComponentArea | const int | 0 - | 1 | Minimal area of a resulting component | |

inMaxComponentArea | Optional<int> | 0 - | NIL | Maximal area of a resulting component | |

inRemoveBoundaryBlobs | bool | False | Flag indicating whether the blobs on border of the input region should be removed or not | ||

outComponents | Array<Region>& |

### Description

The filter splits the input region into blobs and iteratively joins some of them into bigger components.
Only blobs that are distant from each other by at most inMaxDistance can be joined. The joining order
is determined based on modified distance between two blobs, so the closest ones are joined first.
This modified distance between two blobs is computed as follows:

- The shortest segment connecting two blobs is computed.
- The segment is scaled by \[ 0.5 \cdot (1 + inDistanceBalance) \] along the X axis and by \[ 0.5 \cdot (1 - inDistanceBalance) \] along the Y axis.
- Finally the length of the so scaled segment is computed.

### Examples

### Remarks

This filter is mostly used in **Blob Analysis Technique** please refer to our **Machine Vision Guide - Blob Analysis** article.

### See Also

- SplitRegionIntoBlobs – Splits a region into an array of regions corresponding to its connected components.

- SplitRegionIntoExactlyNComponents – Splits a region into a fixed-size array of regions.