Grain Visualization
Visualize labeled grains as geometric shapes — inscribed discs, bounding boxes, centroid markers, or fitted ellipses. Produces a mask image with the chosen shapes and a labeled field where each grain has a unique integer value. Equivalent to Gwyddion's grain selection visualization (grain_makesel).
Inputs
| Name |
Type |
Required |
Description |
| field |
DATA_FIELD |
Yes |
Source data field providing spatial reference and calibration |
| mask |
IMAGE |
Yes |
Binary grain mask (white = grain region) |
Outputs
| Name |
Type |
Description |
| result |
IMAGE |
Visualization mask with geometric shapes drawn for each grain |
| labeled |
DATA_FIELD |
Labeled field where each connected grain region has a unique integer value |
Controls
| Name |
Type |
Default |
Description |
| style |
dropdown |
inscribed_disc |
Visualization style: inscribed_disc, bounding_box, centroid, or ellipse |
| fill |
BOOLEAN |
False |
When enabled, shapes are filled; when disabled, only outlines are drawn |
Notes
- inscribed_disc: Draws a circle at each grain centroid with the inscribed disc radius (maximum of the distance transform within the grain).
- bounding_box: Draws an axis-aligned rectangle around each grain's bounding box.
- centroid: Draws small cross markers at each grain's centroid.
- ellipse: Fits an ellipse to each grain using the inertia tensor to determine the major/minor axes and orientation angle.
- When fill is disabled, outlines are drawn with approximately 1-2 pixel thickness.
- The labeled output assigns each connected grain region a unique positive integer; background pixels are zero.
- The mask and field must have the same pixel dimensions.
