Pamstack User Manual(0) Pamstack User Manual(0)
pamstack - stack planes of multiple PAM images into one PAM image
pamstack [-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 =.
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.
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
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.
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
This specified 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.
netpbm documentation 01 May 2002 Pamstack User Manual(0)
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