ee_extra.Spectral.core.spectralIndices#

ee_extra.Spectral.core.spectralIndices(x, index='NDVI', G=2.5, C1=6.0, C2=7.5, L=1.0, cexp=1.16, nexp=2.0, alpha=0.1, slope=1.0, intercept=0.0, gamma=1.0, omega=2.0, beta=0.05, k=0.0, fdelta=0.581, kernel='RBF', sigma='0.5 * (a + b)', p=2, c=1.0, lambdaN=858.5, lambdaR=645.0, lambdaG=555.0, online=False, drop=False)[source]#

Computes one or more spectral indices (indices are added as bands) for an image or image collection.

Parameters:

  • x (Union[Image, ImageCollection]) – Image or Image Collectionto compute indices on. Must be scaled to [0,1].

  • index (Union[str, List[str]]) – Index or list of indices to compute.

  • G (Union[float, int]) – Gain factor. Used just for index = ‘EVI’.

  • C1 (Union[float, int]) – Coefficient 1 for the aerosol resistance term. Used just for index = ‘EVI’.

  • C2 (Union[float, int]) – Coefficient 2 for the aerosol resistance term. Used just for index = ‘EVI’.

  • L (Union[float, int]) – Canopy background adjustment. Used just for index = [‘EVI’,’SAVI’].

  • cexp (Union[float, int]) – Exponent used for OCVI.

  • nexp (Union[float, int]) – Exponent used for GDVI.

  • alpha (Union[float, int]) – Weighting coefficient used for WDRVI.

  • slope (Union[float, int]) – Soil line slope. Used just for index = [‘ATSAVI’,’SAVI2’, ‘TSAVI’, ‘WDVI’].

  • intercept (Union[float, int]) – Soil line intercept. Used just for index = [‘ATSAVI’,’SAVI2’, ‘TSAVI’, ‘WDVI’].

  • gamma (Union[float, int]) – Weighting coefficient used for ARVI.

  • omega (Union[float, int]) – Weighting coefficient used for MBWI.

  • beta (Union[float, int]) – Calibration parameter used for NDSIns.

  • k (Union[float, int]) – Slope parameter by soil used for NIRvH2.

  • fdelta (Union[float, int]) – Adjustment factor used for SEVI.

  • kernel (str) – Kernel used for kernel indices. One of ‘linear’, ‘RBF’, ‘poly’.

  • sigma (Union[float, str]) – Length-scale parameter. Used for kernel = ‘RBF’. If str, this must be an expression including ‘a’ and ‘b’. If numeric, this must be positive.

  • p (Union[float, int]) – Kernel degree. Used for kernel = ‘poly’.

  • c (Union[float, int]) – Free parameter that trades off the influence of higher-order versus lower-order terms. Used for kernel = ‘poly’. This must be greater than or equal to 0.

  • online (bool) – Whether to retrieve the most recent list of indices directly from the GitHub repository and not from the local copy.

  • lambdaN (Union[float, int]) – NIR wavelength used for NIRvH2 and NDGI.

  • lambdaR (Union[float, int]) – Red wavelength used for NIRvH2 and NDGI.

  • lambdaG (Union[float, int]) – Green wavelength used for NDGI.

  • drop (bool) – Whether to drop all bands except the new spectral indices.

Return type:

Union[Image, ImageCollection]

Returns:

Image or Image Collection with the computed spectral index, or indices, as new bands.

Examples

>>> import ee
>>> from ee_extra.Spectral.core import spectralIndices
>>> ee.Initialize()
>>> S2 = ee.ImageCollection("COPERNICUS/S2_SR")
>>> spectralIndices(S2,["NDVI","SAVI"],L = 0.5)