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Pamcut User Manual(0)                                    Pamcut User Manual(0)



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]

       [-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.

       There are two ways to specify the rectangle to cut: arguments and options.  Options are easier to remember  and
       read,  more expressive, and allow you to use defaults.  Arguments were the only way available before July 2000.

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

       In any case, remember that you are specifying the rectangle to keep,  not  the  bits  to  discard.   Otherwise,
       you'll  be tempted to believe that -right=9 means to delete the 9 rightmost columns.  (It really means keep the
       stuff up to Column 9 and delete the rest).

       To use options, just code any mixture of the -left, -right, -top, -bottom, -width, and -height  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.

       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 pos-
       itive.  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
       -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 nega-
              tive, it refers to columns numbered -1 at the right, decreasing to the left.

              To delete N columns at the left edge, specify -left=N.

              To delete N columns at the right edge, specify -left=--(N+1).


       -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.

              To delete N rows at the top, specify -top=N.

              To delete N rows at the bottom, specify -bottom=-(N+1).


       -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.


       -pad   If  the rectangle you specify is not entirely within the input image, pamcut fails unless you also spec-
              ify -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 back-
              ground 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.



netpbm documentation             05 April 2005           Pamcut User Manual(0)