NAME
pamstack - stack planes of multiple PAM images into one PAM image
SYNOPSIS
pamstack
[-tupletype tupletype]
[inputfilespec]
All options may be abbreviated to the shortest unique prefix.
DESCRIPTION
Reads multiple PAM or PNM images as input. Produces a PAM image as output,
consisting of all the planes (channels) of the inputs, stacked in the order
specified.
The output is the same dimensions as the inputs, except that the depth is
the sum of the depths of the inputs. It has the same maxval.
pamstack
fails if the inputs are not all the same width, height, and maxval. The
tuple type is a null string unless you specify the
-tupletype
option.
pamchannel
does the opposite of
pamstack:
It extracts individual planes from a single PAM.
Use
pamtopnm
to convert a suitable PAM image to a more traditional PNM (PBM, PGM, or
PPM) image.
One example of using
pamstack
is that some Netpbm programs accept as input a PAM that represents graphic
image with transparency information -- tuple type "RGBA". In Netpbm, such
images were traditionally represented as two images - a PPM for the color
and a PGM for the transparency. To convert a PPM/PGM pair into PAM(RGBA)
input that newer programs require, do something like this:
pamstack -tupletype=RGBA myimage.ppm myalpha.pgm | pamtouil >myimage.uil
OPTIONS
-tupletype tupletype
This specified the tuple type name to be recorded in the output. You may
use any string up to 255 characters. Some programs recognize some names. If
you omit this option, the default tuple type name is null.
SEE ALSO
AUTHOR
Copyright (C) by Bryan Henderson, San Jose CA 2000.08.05
