Returns the distance, as determined by the specified distance metric, to the nearest non-zero valued pixel in the input. The output contains values for all pixels within the given neighborhood size, regardless of the input's mask. Note: the default distance metric returns squared distance.

Image.fastDistanceTransform(neighborhood, units, metric)Image
this: imageImageThe input image.
neighborhoodInteger, default: 256Neighborhood size in pixels.
unitsString, default: "pixels"The units of the neighborhood, currently only 'pixels' are supported.
metricString, default: "squared_euclidean"Distance metric to use: options are `squared_euclidean`, `manhattan` or `chebyshev`.