The Lee Sigma filter is a low-pass filter used to smooth the input image (`input`). The user must specify the dimensions of the filter (`filterx` and `filtery`) as well as the sigma (`sigma`) and M (`m`) parameter.

## Reference

Lee, J. S. (1983). Digital image smoothing and the sigma filter. Computer vision, graphics, and image processing, 24(2), 255-269.

## See Also

mean_filter, gaussian_filter

## Function Signature

`def lee_filter(self, raster: Raster, filter_size_x: int = 11, filter_size_y: int = 11, sigma: float = 10.0, m_value: float = 5.0) -> Raster: ...`

## Project Links

WbW Homepage User Manual Support WbW