sertit.rasters_rio.hillshade¶
- hillshade(dst: Union[str, tuple, rasterio.io.DatasetReader], azimuth: float = 315, zenith: float = 45) -> (<class 'numpy.ma.core.MaskedArray'>, <class 'dict'>)[source]¶
Compute the hillshade of a DEM from an azimuth and elevation angle (in degrees).
Goal: replace gdaldem CLI (https://gdal.org/programs/gdaldem.html)
NB: altitude = 90 - zenith
Warning
It uses a 2nd order gradient instead of Horn’s or Zevenbergen & Thorne’s formula
z_factor is fixed to 1.0
scale managed by dst resolution
Reference: - https://git.earthdata.nasa.gov/projects/GEE/repos/gdal-enhancements-for-esdis/browse/gdal-1.10.0/apps/gdaldem.cpp