Provided by: netpbm_10.0-15_i386 bug


       pnmarith - perform arithmetic on two portable anymaps


       pnmarith        -add|-subtract|-multiply|-difference|-minimum|-maximum.
       pnmfile1 pnmfile2


       Reads two portable anymaps as input.  Performs the specified arithmetic
       operation,  and  produces  a  portable anymap as output.  The two input
       anymaps must be the same width and height.

       The arithmetic is performed between corresponding  pixels  in  the  two
       anymaps,  as  if  maxval  was 1.0, black was 0.0, and a linear scale in
       between.  Results that fall outside of [0..1) are truncated.

       The operator -difference calculates  the  absolute  value  of  pnmarith
       -subtract pnmfile1 pnmfile2, i.e. no truncation is done.

       All flags can be abbreviated to their shortest unique prefix.


       pbmmask(1), pnmpaste(1), pnminvert(1), pnm(5)


       Copyright  (C) 1989, 1991 by Jef Poskanzer.  Lightly modified by Marcel
       Wijkstra <>

                                26 August 1993                     pnmarith(1)