ST_MinDist4ma — Raster processing function that returns the minimum distance (in number of pixels) between the pixel of interest and a neighboring pixel with value.
Return the shortest distance (in number of pixels) between the pixel of interest and the closest pixel with value in the neighborhood.
The intent of this function is to provide an informative data point that helps infer the usefulness of the pixel of interest's interpolated value from ST_InvDistWeight4ma . This function is particularly useful when the neighborhood is sparsely populated.
This function is a specialized callback function for use as a callback parameter to ST_MapAlgebra .