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.
add an example, a script, a trick and tips
examples
source
INPUT="$(cat "$@"
| base64)"
pamstack -tupletype=RGB_ALPHA
<(echo
"$INPUT" | base64
-d | pngtopnm)
\
<(echo
"$INPUT" | base64
-d | pngtopnm -alpha)
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
pam
author
Copyright (C)
by Bryan Henderson, San Jose CA 2000.08.05