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



Table Of Contents


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 abbreviation  of  option  is  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 specifi-
       cations get mixed in an unspecified way.

       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 overspec-
       ify,  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
       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.

       If you are splitting a single image into multiple  same-
       size  images, pamdice is faster than running pamcut mul-
       tiple 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  negative,  it refers to columns num-
              bered -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 non-
              negative 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.


       -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  Stan-
              dard Error.



SEE ALSO
       pnmcrop(1),   pamcomp(1),   pnmpad(1),  pnmcat(1),  pgm-
       slice(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)
