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)