Outlier Mask
Create a mask marking pixels that deviate more than N standard deviations from the mean. Quick way to identify noise spikes and defects. Equivalent to Gwyddion's outliers.c module.
Inputs
| Name |
Type |
Required |
Description |
| field |
DATA_FIELD |
Yes |
Input surface |
Outputs
| Name |
Type |
Description |
| mask |
IMAGE |
Binary mask of outlier pixels |
Controls
| Name |
Type |
Default |
Description |
| sigma_threshold |
FLOAT |
3.0 |
Number of standard deviations beyond which a pixel is an outlier (1.0-10.0) |
| mode |
dropdown |
both |
Which outliers to flag: both (high and low), high only, or low only |
Notes
- A pixel is flagged if its z-score (data - mean) / std exceeds the threshold.
- 3σ catches ~0.3% of pixels in a Gaussian distribution. Use 2σ for aggressive filtering or 5σ for conservative.
- The resulting mask can be fed to Laplace Interpolation or Fractal Interpolation to fill the defects.
- For a uniform (constant) field, no pixels are flagged regardless of threshold.
