10.81. Erode/Dilate Mask

Group (Subgroup)

Processing (Cleanup)

Description

This Filter grows or shrinks the true region of a boolean mask array by one cell-layer per iteration, using standard image-morphology operations. The mask is a cell-level boolean array (typically produced by a threshold operation such as Multi-Threshold Objects) where true marks cells of interest and false marks excluded cells.

Only the Mask array is modified; no other cell data is changed.

The example images below show the IPF-colored data after the filter has run. Black pixels are cells where the mask is false; colored pixels are where the mask is true.

Before Dilation	After Dilation

Before Erosion	After Erosion

When to Use This Filter

Erode the mask to discard the boundary layer of valid cells. Useful before computing feature-level statistics from EBSD data, since cells right at the sample edge are often unreliable even after passing a quality threshold.
Dilate the mask to recover cells that were marked invalid by an over-aggressive threshold but lie immediately adjacent to valid data.

Opening and Closing

Chaining an erode and a dilate pass (with equal iteration counts) performs the two classic compound morphology operations:

Fig. 1: Opening (erode then dilate) removes small isolated true regions and thin protrusions while returning the larger region to about its original size; Closing (dilate then erode) fills small holes and gaps while preserving the outer boundary.

Iterations and Direction

Number of Iterations is in cell-layers. An iteration count of 3 grows or shrinks the true region by 3 cells.
X Direction, Y Direction, and Z Direction toggle whether the morphology is applied along that axis. Disable an axis to perform anisotropic morphology – useful when serial-sectioning resolution is anisotropic (typically Z is coarser than X and Y) and you want to limit growth or shrinking along the fine axes.

Required Input Sources

Mask Array – a boolean cell-level array, typically produced by Multi-Threshold Objects applied to an EBSD confidence index, image quality, or similar scalar.

Input Parameter(s)

Parameter Name	Parameter Type	Parameter Notes	Description
Operation	Choices		Whether to dilate (0) or erode (1)
Number of Iterations	Scalar Value	Int32	Number of erode/dilate iterations to perform
X Direction	Bool		Whether to erode/dilate in the X direction
Y Direction	Bool		Whether to erode/dilate in the Y direction
Z Direction	Bool		Whether to erode/dilate in the Z direction

Input Cell Data

Parameter Name	Parameter Type	Parameter Notes	Description
Selected Image Geometry	Geometry Selection	Image	The target geometry
Mask Array Path	Array Selection	Allowed Types: boolean Comp. Shape: 1	Boolean array where true voxels are used. False voxels are ignored.

Example Pipelines

License & Copyright

Please see the description file distributed with this Plugin

DREAM3D-NX Help

If you need help, need to file a bug report or want to request a new feature, please head over to the DREAM3DNX-Issues GitHub site where the community of DREAM3D-NX users can help answer your questions.