pnmarith

pnmarith(1)                 General Commands Manual                pnmarith(1)

NAME
       pnmarith - perform arithmetic on two portable anymaps

SYNOPSIS
       pnmarith  -add|-subtract|-multiply|-difference|-minimum|-maximum.  pnm-
       file1 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 be-
       tween.  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)