NAME

       pamcut - cut a rectangle out of a PAM, PBM, PGM, or PPM image

SYNOPSIS

       pamcut

       [-left colnum]

       [-right colnum]

       [-top rownum]

       [-bottom rownum]

       [-width cols]

       [-height rows]

       [-pad]

       [-cropleft numcols]

       [-cropright numcols]

       [-croptop numrows]

       [-cropbottom numrows]

       [-verbose]

       [left top width height]

       [pnmfile]

       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).

       pamcut  reads a PAM, PBM, PGM, or PPM image as input and extracts the specified rectangle,
       and produces the same kind of image as output.

       You can specify either the rectangle to cut out and keep or specify the edges to crop  off
       and discard, or a combination.

       To  request  edges  be  cropped  off,  use  options  -cropleft,  -cropright, -croptop, and
       -cropbottom to indicate how many rows or columns to discard.

       For example, -cropleft=50 -cropright=200 means to discard the leftmost  50  and  rightmost
       200 columns.

       To  specify  the rectangle to keep, use -left, -right, -top, -bottom, -width, -height, and
       -pad options.

       For example, -left=50 -right=200 means to keep the 150 columns between Columns 50 and  200
       inclusive.

       You can code any mixture of the options.  What you don't specify defaults.  Those defaults
       are in favor of minimal cutting and in favor of cutting the right and  bottom  edges  off.
       It  is  an error to overspecify, i.e. to specify all three of -left, -right, and -width or
       -top, -bottom, and -height or right as well as -cropright.

       There is an older way to specify the rectangle to keep: positional  arguments.   Arguments
       were  the  only  way  available  before  July  2000,  but  you  should not use them in new
       applications.  Options are easier to remember and read, more expressive, and allow you  to
       use defaults.

       If  you use both options and arguments, the two specifications get mixed in an unspecified
       way.

       To use arguments, specify all four of the left, top, width, and  height  arguments.   left
       and top have the same effect as specifying them as the argument of a -left or -top option,
       respectively.  width and height have the same effect as specifying them as the argument of
       a  -width  or  -height  option, respectively, where they are positive.  Where they are not
       positive, they have the same effect as specifying one less than the value as the  argument
       to a -right or -bottom option, respectively.  (E.g. width = 0 makes the cut go all the way
       to the right edge).  Before July 2000, negative numbers were not  allowed  for  width  and
       height.

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

       Output is to Standard Output.

       pamcut  works on a multi-image stream.  It cuts each image in the stream independently and
       produces a multi-image stream output.  Before Netpbm 10.32 (March 2006),  it  ignored  all
       but the first image in the stream.

       If  you are splitting a single image into multiple same-size images, pamdice is faster and
       easier than running pamcut multiple times.

       pamcomp is also useful for cutting and padding an image to a certain size.  You  create  a
       background image of the desired frame dimensions and overlay the subject image on it.

OPTIONS

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

       -left=colnum
              The column number of the leftmost column to be in the output.  Columns left of this
              get cut out.  If a nonnegative number, it refers to columns numbered from 0 at  the
              left,  increasing  to  the right.  If negative, it refers to columns numbered -1 at
              the right, decreasing to the left.

       -right=colnum
              The column number of the rightmost column to be in the output, numbered the same as
              for -left.  Columns to the right of this get cut out.

       -top=rownum
              The  row  number  of  the topmost row to be in the output.  Rows above this get cut
              out.  If a nonnegative number it refers  to  rows  numbered  from  0  at  the  top,
              increasing  downward.  If negative, it refers to columns numbered -1 at the bottom,
              decreasing upward.

       -bottom=rownum
              The row number of the bottom-most row to be in the output, numbered the same as for
              -top.  Rows below this get cut out.

       -width=cols
              The number of columns to be in the output.  Must be positive.

       -height=rows
              The number of rows to be in the output.  Must be positive.

       -cropleft

       -cropright

       -croptop

       -cropbottom
              These  options  tell how many rows or columns to crop from the left, right, top, or
              bottom edges, respectively.

              The value must not be negative.

              These option were new in Netpbm  10.85  (December  2018).   Before  that,  you  can
              achieve the same thing with -left, top, and negative values for -right and -bottom.
              Remember to subtract one in the latter case; e.g. the equivalent of -cropright=1 is
              -right=-2.

       -pad   If  the  rectangle you specify is not entirely within the input image, pamcut fails
              unless you also specify -pad.  In that case, it pads the output with  black  up  to
              the  edges  you  specify.   You can use this option if you need to have an image of
              certain dimensions and have an image of arbitrary dimensions.

              pnmpad also adds borders to an image, but you specify their width directly.

              pamcomp does a more general form of this padding.  Create a background image of the
              frame  dimensions and overlay the subject image on it.  You can use options to have
              the subject image in the center of the frame or  against  any  edge  and  make  the
              padding any color (the padding color is the color of the background image).

       -verbose
              Print information about the processing to Standard Error.

SEE ALSO

       pnmcrop(1), pamdice(1), pamcomp(1), pnmpad(1), pnmcat(1), pgmslice(1), pnm(1)

HISTORY

       pamcut was derived from pnmcut in Netpbm 9.20 (May 2001).  It was the first Netpbm program
       adapted to the new PAM format and programming library.

       The predecessor pnmcut was one of the oldest tools in the Netpbm package.

AUTHOR

       Copyright (C) 1989 by Jef Poskanzer.

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/pamcut.html