Spectral Indices¶
Spectral indices output a single value between -1 and 1 for each pixel. Unless you want to display a grayscale image, you probably want to apply a colormap after computing the index.
normalizedDifference¶
Computes the normalized difference of two bands:
normalized_difference = (x - y) / (x + y)
normalized_difference always uses the first two bands in the pre-assembled
image as x and y respectively.
To create the Normalized difference vegetation index (NDVI), for
example, you would pass the near-infrared band and the red band as the first two
images to the imageBands prop in the combineBands module.
enhancedVegetationIndex¶
Computes the Enhanced Vegetation Index (EVI).
Layers are expected to exist as near-infrared, red, and blue bands on the
input image, respectively. For example, with Landsat 8 data, you would pass
bands 5, 4, and 2 to the imageBands prop in the combineBands
module in that order.
soilAdjustedVegetationIndex¶
Computes the Soil Adjusted Vegetation Index (SAVI).
Layers are expected to exist as near-infrared and red bands on the input
image, respectively. For example, with Landsat 8 data, you would pass bands 5
and 4 to the imageBands prop in the combineBands module in
that order.
modifiedSoilAdjustedVegetationIndex¶
Computes the Modified Soil Adjusted Vegetation Index (MSAVI).
Layers are expected to exist as near-infrared and red bands on the input
image, respectively. For example, with Landsat 8 data, you would pass bands 5
and 4 to the imageBands prop in the combineBands module in
that order.