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 pamcat.
       pamcat 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 ), 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, pamcat is the best substitute.

SEE ALSO

       pamdice(1), pamcat(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

netpbm documentation                              26 April 2020                         Pamundice User Manual(1)