pnmarith(1)

NAME

   pnmarith - perform arithmetic on two portable anymaps

SYNOPSIS

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

DESCRIPTION

   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.

SEE ALSO

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

AUTHOR

   Copyright  (C) 1989, 1991 by Jef Poskanzer.  Lightly modified by Marcel
   Wijkstra <wijkstra@fwi.uva.nl>

                            26 August 1993                     pnmarith(1)

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Free and Open Source Software