Mask Shift
Translate a binary mask by an integer pixel offset. Choose how out-of-bounds regions are filled: zero (empty), wrap (periodic roll), or mirror (reflected padding). Equivalent to Gwyddion's mask_shift.c.
Inputs
| Name |
Type |
Required |
Description |
| mask |
IMAGE |
Yes |
Binary mask to shift |
| field |
DATA_FIELD |
No |
Optional field for preview background display |
Outputs
| Name |
Type |
Description |
| mask |
IMAGE |
Shifted binary mask |
Controls
| Name |
Type |
Default |
Description |
| shift_x |
INT |
0 |
Horizontal shift in pixels (-1000 to 1000). Positive values shift right. |
| shift_y |
INT |
0 |
Vertical shift in pixels (-1000 to 1000). Positive values shift down. |
| border_mode |
dropdown |
zero |
How to handle edges: zero fills vacated region with empty mask, wrap rolls periodically, mirror reflects at boundaries |
Notes
- Shift values are in pixels, not physical units.
- zero mode: the mask is rolled and the vacated strip is cleared to zero (unmasked). Useful when the shifted region should not wrap around.
- wrap mode: uses periodic rolling (
np.roll). The total number of masked pixels is preserved. Suitable for periodic or tiled data.
- mirror mode: pads with reflected values before cropping, so edges are filled with a mirrored copy of the mask boundary. Avoids hard cutoffs at the border.
