eolearn.features.ndi

A collection of bands extraction EOTasks

class eolearn.features.ndi.NormalizedDifferenceIndexTask(input_feature, output_feature, bands, acorvi_constant=0, undefined_value=nan)[source]

Bases: MapFeatureTask

The task calculates a Normalized Difference Index (NDI) between two bands A and B as:

\(NDI = \dfrac{A-B+c}{A+B+c}\),

where c is provided as the acorvi_constant argument. For the reasoning behind using the acorvi_constant in the equation, check the article Using NDVI with atmospherically corrected data.

Parameters:

  • input_feature (Feature) – A source feature from which to take the bands.

  • output_feature (Feature) – An output feature to which to write the NDI.

  • bands (tuple[int, int]) – A list of bands from which to calculate the NDI.

  • acorvi_constant (float) – A constant to be used in the NDI calculation. It is set to 0 by default.

  • undefined_value (float) – A value to override any calculation result that is not a finite value (e.g.: inf, nan).

map_method(feature)[source]
Parameters:

feature (ndarray) – An eopatch on which to calculate the NDI.

Return type:

ndarray