Do some simple filtering on grey scale images.

Online Help:

Usage: /vol/vssp/local/trees/amma-4/linux/bin/BWFilt [options] 
   -optload () [] Load options from a file.  
   -optsave () [] Save options to a file.  
   -if () [] Input format type. 
   -of () [] Output format type. 
   -s (3) [3] Size of filter to use.  
   -r (FALSE) [FALSE] Use rank order filter.
   -rs (FALSE) [FALSE] Use soft rank order filter.
   -ns (FALSE) [FALSE] Use Square filter. (default)
   -nc (FALSE) [FALSE] Use Circular filter. 
   -nb (FALSE) [FALSE] Use City-Block filter. 
   -ss (TRUE) [TRUE] Sub-sample image.
   -v (FALSE) [FALSE] Verbose mode. 
   -seq (FALSE) [FALSE] Process a sequence. 
   arg (in.pgm) [in.pgm] Input file name. 
   arg (out.pgm) [out.pgm] Output file name. 
   -help (TRUE) [FALSE] Print usage information. 

Dependancies:
   -r and -ss and -rs are mutually exclusive
   -ns and -nc and -nb are mutually exclusive