pnmarith(1)                                           pnmarith(1)


NAME
       pnmarith - perform arithmetic on two portable anymaps

SYNOPSIS
       pnmarith -add|-subtract|-multiply pnmfile1 pnmfile2

DESCRIPTION
       Reads  two portable anymaps as input.  Performs the speci-
       fied 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.

       All flags can be abbreviated to their shortest unique pre-
       fix.

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

AUTHOR
       Copyright (C) 1989, 1991 by Jef Poskanzer.
































                         13 January 1991                        1