xrspatial.morphology.morph_black_tophat#

xrspatial.morphology.morph_black_tophat(agg, kernel=None, boundary='nan', name='black_tophat')[source]#

Black top-hat: closing minus original.

Isolates dark features that are smaller than the structuring element.

Parameters:

  • agg (xarray.DataArray) – 2D raster of numeric values.

  • kernel (numpy.ndarray or None) – 2D structuring element with odd dimensions. Defaults to a 3x3 square.

  • boundary (str, default 'nan') – Edge handling: 'nan', 'nearest', 'reflect', or 'wrap'.

  • name (str, default 'black_tophat') – Name for the output DataArray.

Returns:

Black top-hat raster (closing - original).

Return type:

xarray.DataArray

Examples

>>> from xrspatial.morphology import morph_black_tophat
>>> dark = morph_black_tophat(elevation, kernel=circle_kernel)