

r.thin - 

r.thin scans a \raster\ file and thins non-zero cells that denote
linear features into linear features having a single cell width.
The program will thin only the non-zero cells of the input raster
file within the current \geographic region\ settings.  The cell width
of the thinned output raster file will be equal to the cell
\resolution\ of the currently set geographic region.

Manual entry for \r.thin\
