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>