pamcut
Updated: 03 August 2000
Table Of Contents
NAME
pamcut - cut a rectangle out of a PAM, PBM, PGM, or PPM image
SYNOPSIS
pamcut [-left leftcol] [-right rightcol] [-top toprow] [-bot-
tom bottomrow]
[-width width] [-height height] [-pad] [-verbose] [left top
width height]
[pnmfile]
Minimum unique abbreviation of option is acceptable. You may
use double
hypens 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.
pamcut reads a PAM, PBM, PGM, or PPM image as input and ex-
tracts 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 Ju-
ly 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, -bottom,
-width, and -height options. What you don't specify defaults.
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 val-
ue 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 multiple times.
OPTIONS
-left
The column number of the leftmost column to be in the
output. 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
The column number of the rightmost column to be in the
output,
numbered the same as for -left.
-top
The row number of the topmost row to be in the out-
put. 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
The row number of the bottom-most row to be in the out-
put, numbered
the same as for -top.
-width
The number of columns to be in the output. Must be pos-
itive.
-height
The number of rows to be in the output. Must be posi-
tive.
-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 dimen-
sions and have an
image of arbitrary dimensions.
pnmpad also adds borders to an image, but you specify
their width
directly.
-verbose
Print information about the processing to Standard Er-
ror.
SEE ALSO
pnmcrop, pnmpad, pnmcat, pgmslice, pnm
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.
_________________________________________________________________
Table Of Contents
* NAME
* SYNOPSIS
* DESCRIPTION
* OPTIONS
* SEE ALSO
* AUTHOR
UNIX/Linux commands referenced on this page:
- cut
- as
- more
- top
- less
- column
- at
- pnmpad
- pnmcrop
- pnmcat
- pgmslice
- pnmcut