Connected Components

Splits a region into a list of multiple spatially disconnected regions.

Inputs

Region (Type: Region)

The input region.

DistanceX (Type: Int32)

A horizontal distance. Pixels within this horizontal distance are considered to be connected.

DistanceY (Type: Int32)

A vertical distance. Pixels within this horizontal distance are considered to be connected.

Outputs

Blobs (Type: RegionList)

The resulting list of disconnected regions.

BlobColors

A list of colors that can be used to color the regions in a way that expresses their separated nature by using different colors (the list contains six distinct colors that are repeated).

Comments

Usually, connectedness is specified using the terms 4-connected and 8-connected in the literature. 4-connected means that objects touching only at the diagonal pixels are separated, 8-connected means that such objects are not separated. The two distance parameters can be used to specify 4-connectedness (DistanceX == 0, DistanceY == 0) or 8-connectedness (DistanceX == 1, DistanceY == 1). Bigger values of the distance parameters can jump over gaps and still treat objects as being connected.

Using this pipeline:

the following region has been created by thresholding:

and the following list of regions has been created by separating objects with the Connected Components node: