# Opening

Apply the morphological opening operation on a binary mask. The morphological opening of a binary mask $$I$$ is defined as the dilation of the erosion of the mask: $$\textrm{Opening}\left(I\right) = \textrm{Dilatation}\left(\textrm{Erosion}\left(I\right)\right)$$.

This filter removes small foreground structures in the mask. The size of the affected structures is controlled by the shape and size of the kernel.

## Inputs

Type: Image4DBool, Required, Single

## Outputs

#### Out

A binary mask with the same spatial properties as the input mask.

Type: Image4DBool

## Settings

#### Kernel Selection

The shape of the structuring element.

Values: Annulus, Ball, Box, Cross

The radius of the kernel in the X direction, specified in voxels.