Pamstack User Manual(0)				       Pamstack User Manual(0)



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.  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 ALSO
       pam(1) pamchannel(1)


HISTORY
       pamstack was new in Netpbm 10.0 (June 2002).



netpbm documentation		10 January 2006	       Pamstack User Manual(0)