This tool can be used to calculate the difference between the elevation of each grid cell and the mean elevation of the centering local neighbourhood. This is similar to what a high-pass filter calculates for imagery data, but is intended to work with DEM data instead. This attribute measures the relative topographic position. `DiffFromMeanElev` utilizes an integral image approach (Crow, 1984) to ensure highly efficient filtering that is invariant with filter size.

The user must specify a digital elevation model (DEM) (`dem`) , and the size of the neighbourhood in the x and y directions (`filterx` and `filtery`), measured in grid size.

While `DevFromMeanElev` calculates the DIFF at a single, user-defined scale, the max_difference_from_mean tool can be used to output the per-pixel maximum DIFF value across a range of input scales.

## See Also

`DevFromMeanElev`, max_difference_from_mean

## Function Signature

`def difference_from_mean_elevation(self, dem: Raster, filter_size_x: int = 11, filter_size_y: int = 11) -> Raster: ...`

## Project Links

WbW Homepage User Manual Support WbW