Terrain Mask |

### Terrain Mask

The Terrain Mask operator uses a DEM to determine large slopes in elevation over a window. This is useful for feature extraction on plateaus by masking out mountainous areas.

The following parameters are used by the operator:

1. Digital Elevation Model: The choice of elevation model.
2. DEM Resampling Method: Resampling method applied to the DEM in order to match the image resolution.
3. Window Size: Convolution filter window size.
4. Threshold: The threshold difference in metres between the minimum and maximum elevation within a window.

If the slope between the min and max elevations within a window exceeds the threshold then the operator will mask out the pixel.