Cross-Correlate
Compute 2D cross-correlation between two fields. The correlation peak indicates the offset where the two fields best match. Useful for drift measurement and feature alignment. Equivalent to Gwyddion crosscor.c.
Inputs
| Name |
Type |
Required |
Description |
| field_a |
DATA_FIELD |
Yes |
First input field |
| field_b |
DATA_FIELD |
Yes |
Second input field |
Outputs
| Name |
Type |
Description |
| correlation |
DATA_FIELD |
Cross-correlation map |
Controls
| Name |
Type |
Default |
Description |
| mode |
dropdown |
same |
Output size: full (Na+Nb-1), same (same as field_a), or valid (overlapping region only) |
| normalize |
BOOLEAN |
True |
Normalize the result to [-1, 1] by dividing by the product of RMS values |
Notes
- Both fields must be of compatible numpy array types; very different sizes in full mode produce large outputs.
- Mean is subtracted before correlation; absolute offset information is lost.
