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.

       It can also just change the tuple type of a single PAM image.

       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.  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.

       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) to convert a suitable PAM 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 information.  Taking a color image for example,
       this  would  be  a  PAM  with  tuple  type  "RGB_ALPHA".   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(RGB_ALPHA)  input  that  newer  programs
       require, do something like this:

       $ pamstack -tupletype=RGB_ALPHA myimage.ppm myalpha.pgm | \
             pamtouil >myimage.uil

OPTIONS

       In addition to the options common to all programs based on libnetpbm (most notably -quiet,
       see
        Common Options ⟨index.html#commonoptions⟩ ), pamstack recognizes  the  following  command
       line option:

       -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 recognize 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).

DOCUMENT SOURCE

       This  manual page was generated by the Netpbm tool 'makeman' from HTML source.  The master
       documentation is at

              http://netpbm.sourceforge.net/doc/pamstack.html