Extend Pad
Add configurable borders around a DATA_FIELD using various padding methods. Useful for preparing data for FFT-based operations that suffer from edge artifacts, or for aligning fields of different sizes. Equivalent to Gwyddion's extend.c module.
Inputs
| Name |
Type |
Required |
Description |
| field |
DATA_FIELD |
Yes |
Input field to pad |
Outputs
| Name |
Type |
Description |
| padded |
DATA_FIELD |
Field with added borders |
Controls
| Name |
Type |
Default |
Description |
| left |
INT |
0 |
Number of pixels to add on the left edge (0–1024) |
| right |
INT |
0 |
Number of pixels to add on the right edge (0–1024) |
| top |
INT |
0 |
Number of pixels to add on the top edge (0–1024) |
| bottom |
INT |
0 |
Number of pixels to add on the bottom edge (0–1024) |
| method |
dropdown |
mirror |
Padding method: mean (fill with field mean), edge (replicate border pixels), mirror (reflect across edge), periodic (tile the field), or zero (fill with zeros) |
Notes
- Mirror and periodic padding avoid sharp discontinuities at the border and are recommended before FFT-based filtering.
- Edge padding replicates the outermost row/column of pixels into the border region.
- Zero padding fills borders with 0.0 and can introduce step artifacts; consider mean padding as an alternative.
- The output field's physical dimensions are extended proportionally to the added pixels.
