

r.neighbors - 

r.neighbors looks at each \cell\ in a raster input file and examines
the \category values\ assigned to the cell in some user-defined
"neighborhood" around it.  It outputs a new raster map layer in which
each cell is assigned a category value that is a user-specified
function of the values in that cell's neighborhood.  For example, each
cell in the output layer might be assigned a category value equal to the
average of the category values appearing in its 3 X 3 cell
"neighborhood" in the input layer.

Manual entry for \r.neighbors\
