man > pamundice(1)

Pamundice User Manual(1)               General Commands Manual              Pamundice User Manual(1)

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 pa‐
       mundice 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 subrou‐
       tine).   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 be‐
              fore 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)