pamcut



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 abbreviation of option is acceptable.  You may use dou-
       ble 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.

       To use options, just code any mixture of the -left, -right, -top, -bot-
       tom, -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 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 pnm-
       file.

       Output is to Standard Output.

       If you are splitting a single image  into  multiple  same-size  images,
       pamdice is faster 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 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 nega-
              tive, 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, num-
              bered 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 Standard Error.




SEE ALSO

       pnmcrop(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  pack-
       age.




AUTHOR

       Copyright (C) 1989 by Jef Poskanzer.



netpbm documentation             05 April 2005           Pamcut User Manual(0)

Man(1) output converted with man2html