\
.\" This man page was generated by the Netpbm tool 'makeman' from HTML source.
.\" Do not hand-hack it!  If you have bug fixes or improvements, please find
.\" the corresponding HTML page on the Netpbm website, generate a patch
.\" against that, and send it to the Netpbm maintainer.
.TH "Pamrestack User Manual" 0 "" "netpbm documentation"

Updated:
.SH NAME
pamrestack - Rearrange rows of a Netpbm image

.UN synopsis
.SH SYNOPSIS

\fBpamrestack\fP

[\fB-width=\fP\fIwidth\fP]

[\fB-trim=\fP{\fBfill\fP|\fBcrop\fP|\fBabort\fP}]

[\fB-verbose\fP]

[\fIpamfile\fP]
.PP
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.

.UN description
.SH DESCRIPTION
.PP
This program is part of
.BR "Netpbm" (1)\c
\&.
.PP
\fBpamrestack\fP 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.
.PP
Put another way, \fBpamrestack\fP arranges all the input rows into one
long sequence and produces output rows therefrom, in FIFO order.
.PP
Input is from Standard Input if you don't specify the input
file \fIpamfile\fP.
.PP
Output is to Standard Output.
.PP
\fBpamrestack\fP works on a multi-image stream.  It cuts each image in the
stream independently and produces a multi-image stream output.


.UN options
.SH OPTIONS
.PP
In addition to the options common to all programs based on libnetpbm
(most notably \fB-quiet\fP, see 
.UR index.html#commonoptions
 Common Options
.UE
\&), \fBpamrestack\fP recognizes the following
command line options:


.TP
\fB-width=\fP\fIwidth\fP
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.

.TP
\fB-trim=\fP{\fBfill\fP|\fBcrop\fP|\fBabort\fP}
This option specifies what to do when the new width does not cleanly
divide the number of pixels in the input image.


.TP
\fBfill\fP
  
(Default) Complete the final row by adding black pixels as necessary.

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

.TP
\fBabort\fP
  
Fail the program..

  
.TP
\fB-verbose\fP
Print information about the processing to Standard Error.



.UN usage
.SH USAGE  
.PP
\fBpamrestack\fP is a general editor with many possible uses.

.IP \(bu

    \fBpamrestack\fP can rearrange into rectangles single-dimension images
    produced by programs such as \fBppmhist\fP and \fBpamseq\fP.  This makes
    the output easier to examine with a viewer.  Conversely, \fBpamrestack\fP
    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.

.IP \(bu

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

.IP \(bu
\fBpamrestack\fP can be used with \fBpamdice\fP, \fBpamundice\fP,
    \fBpnmcat\fP, etc. to divide and combine images in the process of
    interlacing.
  


.UN examples
.SH EXAMPLES


.IP \(bu
Rearrange the one-dimensional output of \fBpamseq\fP into a square:

.nf
\f(CW
pamseq 3 255 | pamrestack -width=4096
\fP

.fi

.IP \(bu
Combine two files, each 600 pixels wide, one with the odd rows and
  another with the even rows, to construct an interlaced image:

.nf
\f(CW
pnmcat -leftright oddrows.ppm evenrows.ppm | pamrestack -width=600
\fP

.fi


.IP \(bu
Like the above, but invert all pixels in the even rows left to right
  to produce a serpentine interlace:

.nf
\f(CW
  pamflip -leftright evenrows.ppm |
    pnmcat -leftright oddrows.ppm - |
      pamrestack -width 600
\fP

.fi



.UN seealso
.SH SEE ALSO
.BR "pamseq" (1)\c
\&,
.BR "ppmhist" (1)\c
\&,
.BR "pnmshear" (1)\c
\&,
.BR "pamscale" (1)\c
\&,
.BR "pamdeinterlace" (1)\c
\&,
.BR "pamdice" (1)\c
\&,
.BR "pamundice" (1)\c
\&,
.BR "pnmcat" (1)\c
\&,
.BR "pam" (1)\c
\&


.UN history
.SH HISTORY
.PP
\fBpamrestack\fP was new in Netpbm 10.99 (June 2022).


.UN author
.SH AUTHOR

By Akira F. Urushibata.  Contributed to the public domain by the author.
.SH DOCUMENT SOURCE
This manual page was generated by the Netpbm tool 'makeman' from HTML
source.  The master documentation is at
.IP
.B http://netpbm.sourceforge.net/doc/pamrestack.html
.PP