Pamstack User Manual(0) Pamstack User Manual(0)NAMEpamstack - stack planes of multiple PAM images into one PAM image
SYNOPSISpamstack [-tupletype tupletype] [inputfilespec ...]
All options may be abbreviated to the shortest unique prefix. You may
use two hyphens instead of one. You may separate an option from its
value with a space instead of =.
DESCRIPTION
This program is part of Netpbm(1).
pamstack reads multiple PAM or PNM images as input and produces a PAM
image as output, consisting of all the planes (channels) of the inputs,
stacked in the order specified.
For any one (but not more) of the input files, you may specify '-' to
mean Standard Input. If you specify no arguments at all, the input is
one file: Standard Input.
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. pam‐
stack fails if the inputs are not all the same width, height, and max‐
val. The tuple type is a null string unless you specify the -tupletype
option.
pamstack works with multi-image streams. It stacks the 1st image in
all the streams into one output image (the first one in the output
stream), then stacks the 2nd image in all the streams into the 2nd
image in the output stream, and so on, until one of the streams runs
dry. It's like a matrix operation.
Before Netpbm 10.32 (February 2006), pamstack ignored all but the first
image in each input stream.
pamchannel does the opposite of pamstack: It extracts individual
planes from a single PAM.
Use pamtopnm(1)toconvertasuitablePAM image to a more traditional PNM
(PBM, PGM, or PPM) image. (But there's no need to do that if you're
going to feed it to a modern Netpbm program -- they all take suitable
PAM input directly).
One example of using pamstack is that some Netpbm programs accept as
input a PAM that represents graphic image with transparency informa‐
tion. Taking a color image for example, this would be a PAM with tuple
type "RGB_ALPHA". In Netpbm, such images were traditionally repre‐
sented as two images - a PPM for the color and a PGM for the trans‐
parency. To convert a PPM/PGM pair into PAM(RGB_ALPHA) input that
newer programs require, do something like this:
$ pamstack -tupletype=RGB_ALPHA myimage.ppm myalpha.pgm | \
pamtouil >myimage.uil
OPTIONS-tupletype tupletype
This specifies the tuple type name to be recorded in the output.
You may use any string up to 255 characters. Some programs rec‐
ognize some names. If you omit this option, the default tuple
type name is null.
SEE ALSOpam(1)pamchannel(1)HISTORYpamstack was new in Netpbm 10.0 (June 2002).
netpbm documentation 10 January 2006 Pamstack User Manual(0)