Provided by: netpbm_10.0-15_amd64 bug


       pbmclean - flip isolated pixels in portable bitmap


       pbmclean [-minneighbors=N] [-black|-white] [pbmfile]

       You  can  use  the  minimum  unique  abbreviation of the options.  You can use two hyphens
       instead of one.  You can separate an option name from its value with white  space  instead
       of an equals sign.

       Before December 2001, pbmclean accepted -N instead of -minneighbors.


       pbmclean cleans up a PBM image of random specs.  It reads a PBM image as input and outputs
       a PBM that is the same as the input  except  with  every  pixel  which  has  less  than  N
       identical neighbours inverted.

       The default for N is 1 - only completely isolated pixels are flipped.

       (A  value  of N greater than 8 generates a completely inverted image (but use pnminvert to
       do that) -- or a completely white or completely black image  with  the  -black  or  -white

       pbmclean considers the area beyond the edges of the image to be white.  (This matters when
       you consider pixels right on the edge of the image).

       You can use pbmclean to clean up "snow" on bitmap images.



       -white Flip pixels of the specified color.  By default, if you specify neither -black  nor
              -white,  pbmclean  flips  both  black and white pixels which do not have sufficient
              identical neighbors.  If you specify -black, pbmclean leaves the white pixels alone
              and  just  erases  isolated  black pixels.  Vice versa for -white.  You may specify
              both -black and -white to get the same as the default behavior.




       Copyright (C) 1990 by Angus Duggan Copyright (C) 1989 by  Jef  Poskanzer.   Copyright  (C)
       2001 by Michael Sternberg.

       Permission  to  use,  copy, modify, and distribute this software and its documentation for
       any purpose and without fee is hereby granted, provided that the  above  copyright  notice
       appear in all copies and that both that copyright notice and this permission notice appear
       in supporting documentation.  This software is provided "as is" without express or implied

                                           18 Oct 2001                                pbmclean(1)