10.67. Create Feature Boundaries (2D)
Group (Subgroup)
Surface Meshing (Generation)
Description
This Filter extracts the 2D boundaries between Features in an Image Geometry and builds an Edge Geometry that traces the outlines of those features. An Image Geometry is a regular grid of rectangular cells (pixels in 2D). A Feature is a connected region of cells that share the same identifier, recorded in a Feature IDs array (one integer label per cell). An Edge Geometry is a node-based geometry made of straight line segments (edges); here each edge lies on the interface between two cells that belong to different features.
The filter operates only in the XY plane and requires the input Image Geometry to have a Z dimension of 1 (a single slice).
NOTE: The Feature IDs array can be any integer type, not just the signed int32 type used by typical feature-id arrays. This means it can operate directly on scalar images that have not been segmented. For example, the user could run a simple threshold to create a uint8 mask (a boolean per-cell flag stored as 0/1) and feed that mask in as the Feature IDs input. This is useful for outlining just the sample border when there is overscan — extra collected area surrounding the actual sample — or for outlining specific regions of a 2D Image Geometry.
The algorithm scans the Feature IDs array and identifies boundaries where adjacent cells have different feature IDs. For each such boundary, an edge (line segment) is created along the shared cell interface. The resulting Edge Geometry contains:
Shared Vertex List: 3D coordinates of all unique vertices at feature boundaries
Shared Edge List: connectivity pairs defining the line segments between those vertices
Z Value Source
The Z Value Source parameter provides the following choices:
Use min z value from Image geometry [0]: Uses the origin Z value of the input Image Geometry as the Z coordinate for all generated vertices.
Use max z value from Image geometry [1]: Uses the origin Z plus the spacing times the Z dimension as the Z coordinate for all generated vertices.
Use Custom z Offset [2]: Lets the user specify an arbitrary Z coordinate value for all generated vertices.
Algorithm Details
The algorithm uses a two-pass approach for efficiency:
Count Pass: Scans to count the total number of boundary edges (both vertical and horizontal).
Populate Pass: Creates the vertices and edge connectivity.
After edge creation, duplicate vertices are eliminated to ensure a clean, connected edge network.
Example Output
Required Input Sources
Image Geometry – a 2D Image Geometry (Z dimension of 1) holding the Feature IDs.
Feature IDs – a per-cell integer array. It may be a true segmentation produced by Segment Features (Scalar), or any per-cell integer/mask array produced by a thresholding filter such as Multi-Threshold Objects.
Input Geometry
Parameter Name |
Parameter Type |
Parameter Notes |
Description |
|---|---|---|---|
Input Image Geometry |
Geometry Selection |
Image |
The input image geometry to create grain boundaries. |
Input Cell Data
Parameter Name |
Parameter Type |
Parameter Notes |
Description |
|---|---|---|---|
Feature Ids |
Array Selection |
Allowed Types: int8, uint8, int16, uint16, int32, uint32, int64, uint64 Comp. Shape: 1 |
The feature ids that will be used to draw the boundary edge geometry. |
Z Value Options
Parameter Name |
Parameter Type |
Parameter Notes |
Description |
|---|---|---|---|
Z Value Source |
Choices |
Select the source for the Z coordinate of the generated vertices |
|
Custom Z Value |
Scalar Value |
Float32 |
The custom Z offset value for the generated vertices |
Edge Extraction Options
Parameter Name |
Parameter Type |
Parameter Notes |
Description |
|---|---|---|---|
Extract Edges of Virtual Sample |
Bool |
Whether to extract the outer edges of the image geometry |
Output Geometry
Parameter Name |
Parameter Type |
Parameter Notes |
Description |
|---|---|---|---|
Output Edge Geometry |
DataGroupCreation |
The name of the created Edge Geometry |
Example Pipelines
ExtractFeatureBoundaries2D.d3dpipeline
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.