Manual: pamrestack

Pamrestack User Manual(1)			   General Commands Manual			   Pamrestack User Manual(1)

Updated:

NAME
       pamrestack - Rearrange rows of a Netpbm image

SYNOPSIS
       pamrestack

       [-width=width]

       [-trim={fill|crop|abort}]

       [-verbose]

       [pamfile]

       Minimum unique abbreviations of option are acceptable.  You may use double hyphens instead of single hyphen to denote
       options.	 You may use white space in place of the equals sign to separate an option name from its value.

DESCRIPTION
       This program is part of Netpbm(1).

       pamrestack rearranges the pixels of a Netpbm image into different size rows.  E.g. if an image is 100 pixels wide and
       50  pixels high, you can rearrange it to 125 wide and 40 high.  In that case, 25 pixels from the start of the 2nd row
       of the input would be moved to the end of the 1st row of input, 50 pixels from the 3rd row would be moved to the	 2nd
       row, etc.

       Put another way, pamrestack arranges all the input rows into one long sequence and produces output rows therefrom, in
       FIFO order.

       Input is from Standard Input if you don't specify the input file pamfile.

       Output is to Standard Output.

       pamrestack  works on a multi-image stream.  It cuts each image in the stream independently and produces a multi-image
       stream output.

OPTIONS
       In addition to the options common to all programs based on libnetpbm (most notably  -quiet,  see	  Common Options  ),
       pamrestack recognizes the following command line options:

       -width=width
	      The width of the output.	If this option is not specified, the output will
		consist of a single row wide enough to contain all the pixels of the input
		image.

       -trim={fill|crop|abort}
	      This  option specifies what to do when the new width does not cleanly divide the number of pixels in the input
	      image.

       fill

	      (Default) Complete the final row by adding black pixels as necessary.

       crop

	      Discard the final partial row.  If this means there is nothing to
		  output, fail the program.

       abort

	      Fail the program.

       -verbose
	      Print information about the processing to Standard Error.

USAGE
       pamrestack is a general editor with many possible uses.

       •
		  pamrestack can rearrange into rectangles single-dimension images
		  produced by programs such as ppmhist and pamseq.  This makes
		  the output easier to examine with a viewer.  Conversely, pamrestack
		  can be used to convert a normal rectangular image into one wide row or one
		  tall column if that is desirable for compression, conversion, or analysis.

       •
		  pamrestack can repair images corrupted by an incorrect width value
		  in the header.  Images grabbed from the framebuffer device often exhibit
		  this problem.

       •      pamrestack can be used with pamdice, pamundice,
		  pamcat, etc. to divide and combine images in the process of
		  interlacing.

EXAMPLES
       •      Rearrange the one-dimensional output of pamseq into a square:

	      pamseq 3 255 | pamrestack -width=4096

       •      Combine two files, each 600 pixels wide, one with the odd rows and
		another with the even rows, to construct an interlaced image:

	      pamcat -leftright oddrows.ppm evenrows.ppm | pamrestack -width=600

       •      Like the above, but invert all pixels in the even rows left to right
		to produce a serpentine interlace:

		pamflip -leftright evenrows.ppm |
		  pamcat -leftright oddrows.ppm - |
		    pamrestack -width 600

SEE ALSO
       pamseq(1), ppmhist(1), pnmshear(1), pamscale(1), pamdeinterlace(1), pamdice(1), pamundice(1), pamcat(1), pam(1)

HISTORY
       pamrestack was new in Netpbm 10.99 (June 2022).

AUTHOR
       By Akira F. Urushibata.	Contributed to the public domain by the author.

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/pamrestack.html

netpbm documentation										   Pamrestack User Manual(1)