NAME

       pamundice - combine grid of images (tiles) into one

EXAMPLE

           $ pamdice myimage.ppm -outstem=myimage_part -width=10 -height=8
           $ pamundice myimage_part_%1d_%1a.ppm -across=10 -down=8 >myimage.ppm

           $ pamundice myimage.ppm myimage_part_%2a -across=13 -hoverlap=9

SYNOPSIS

       pamundice

       [-across=n]

       [-down=n]

       [-hoverlap=pixels]

       [-voverlap=pixels]

       [-verbose]

       {input_filename_pattern, -listfile=filename}

       You  can  use  the  minimum  unique  abbreviation of the options.  You can use two hyphens
       instead of one.  You can separate an option name from its value with white  space  instead
       of an equals sign.

DESCRIPTION

       This program is part of Netpbm(1).

       pamundice  reads  a  bunch  of Netpbm images as input and combines them as a grid of tiles
       into a single output image of the same kind on Standard Output.

       You can optionally make the pieces overlap.

       The images can either be in files whose names indicate where they go in the
         output (e.g. 'myimage_part_03_04' could be the image for Row 3,
         Column 4 - see the input_filename_pattern argument) or listed in a
         file, with a -listfile option.

       The input images must all have the same format (PAM, PPM, etc.)  and maxval  and  for  PAM
       must  have  the  same  depth  and tuple type.  All the images in a rank (horizontal row of
       tiles) must have the same height.  All the images in a file  (vertical  column  of  tiles)
       must  have the same width.  But it is not required that every rank have the same height or
       every file have the same width.

       pamdice is the inverse of pamundice.  You can use pamundice to reassemble an image  sliced
       up  by  pamdice.   You  can  use  pamdice  to  recreate  the  tiles of an image created by
       pamundice, but to do this, the original ranks must all have been the  same  height  except
       for  the  bottom  one  and the original files must all have been the same width except the
       right one.

       One use for this is to process an image in pieces when the whole image  is  too  large  to
       process.  For example, you might have an image so large that an image editor can't read it
       all into memory or processes it very slowly.  You can split it into  smaller  pieces  with
       pamdice, edit one at a time, and then reassemble them with pamundice.

       Of course, you can also use pamundice to compose various kinds of checkerboard images, for
       example, you could write a program to render a chessboard by computing an  image  of  each
       square, then using pamundice to assemble them into a board.

       An  alternative to join images in a single direction (i.e. a single rank or a single file)
       is pnmcat.  pnmcat gives you more flexibility than  pamundice  in  identifying  the  input
       images: you can supply them on Standard Input or as a list of arbitrarily named files.

       To  join piecewise photographs, use pnmstitch instead of pamundice, because it figures out
       where the pieces overlap, even if they don't overlap exactly vertically or horizontally.

       To create an image of the same tile repeated in a grid, that's pnmtile.

       pnmindex does a similar thing to pamundice: it combines a bunch of small images in a  grid
       into  a  big one.  But its purpose is to produce a an index image of the input images.  So
       it leaves space between them and has labels for them, for example.

ARGUMENTS

       Unless you use a -listfile option,, there is one non-option argument, and it is mandatory:
       input_filename_pattern.  This tells pamundice what files contain the input tiles.

       pamundice  reads the input images from files which are named with a pattern that indicates
       their positions in the combined image.  For example, tile_00_05.ppm could be the 6th  tile
       over in the 1st rank, while tile_04_01 is the 2nd tile over in the 5th rank.

       You  cannot  supply any of the data on Standard Input, and the files must be the kind that
       pamundice can close and reopen and read the same image a second time (e.g. a regular  file
       is fine; a named pipe is probably not).

       input_filename_pattern  is  a  printf-style  pattern.   (See the standard C library printf
       subroutine).  For the example above, it would  be  tile_%2d_%2a.ppm.   The  only  possible
       conversion specifiers are:

       d      "down": The rank (row) number, starting with 0.

       a      "across": The file (column) number, starting with 0.

       %      The per cent character (%).

       The  number  between  the % and the conversion specifier is the precision and is required.
       It says how many characters of the file name are described by that conversion.   The  rank
       or file number is filled with leading zeroes as necessary.

       So  the  example tile_%2d_%2a.ppm means to get the name of the file that contains the tile
       at Rank 0, File 5, you:

       •      replace the "%2d" with the rank number, as a 2 digit decimal number: "00"

       •      Replace the "%2a" with the file number, as a 2 digit decimal number: "05"

       Note that this pattern describes  file  names  that  pamdice  produces,  except  that  the
       precision  may  be  more  or less.  (pamdice uses however many digits are required for the
       highest numbered image).

OPTIONS

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

       -across=N
              This is the number of tiles across in the grid, i.e. the number of  tiles  in  each
              rank, or the number of files.

              Default is 1.

       -down=N
              This  is  the  number of tiles up and down in the grid, i.e. the number of tiles in
              each file, or the number of ranks.

              Default is 1.

       -hoverlap=pixels
              This is the amount in pixels to overlap the tiles  horizontally.   pamundice  clips
              this  much off the right edge of every tile before joining it to the adjacent image
              to the right.  The tiles along the right edge remain whole.

              There must not be any input image narrower than this.

              Note that this undoes the effect of the same -hoverlap option of pamdice.

              Default is zero -- no overlap.

       -voverlap=pixels
              This is analogous to -hoverlap, but pamundice clips the bottom edge of  each  image
              before joining it to the one below.

       -listfile=filename
              This  option  names a file that contains the names of all the input files.  This is
              an alternative to specifying a file name pattern as an argument.

              The named file contains file name, one per line.  Each file contains the
                image for one tile, in row-major order, top to bottom, left to right.  So
                the first file is the upper left tile, the second is the one to right of
                that, etc.  The number of lines in the file must be equal to the number of
                tiles in the output, the product of the -across and -down
                values.

              The file names have no meaning to pamundice.  You can use the same
                file multiple times to have identical tiles in the output.

              This option was new in Netpbm 10.90 (March 2020).

       -verbose
              Print information about the processing to Standard Error.

HISTORY

       pamundice was new  in  Netpbm  10.39  (June  2007).   Before  that,  pnmcat  is  the  best
       substitute.

SEE ALSO

       pamdice(1), pnmcat(1), pnmindex(1), pnmtile(1), pnm(1) pam(1)

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/pamundice.html