pamcut
Section: User Commands (1)
Updated: 03 August 2000
Index
Return to Main Contents
NAME
pamcut - cut a rectangle out of a PAM, PBM, PGM, or PPM image
SYNOPSIS
pamcut
[-left leftcol]
[-right rightcol]
[-top toprow]
[-bottom bottomrow]
[-width width]
[-height height]
[-pad]
[-verbose]
[
left right width height
]
[pnmfile]
All options may be abbreviated to the shortest unique prefix.
DESCRIPTION
Reads a PAM, PBM, PGM, or PPM image as input. 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,
-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,
right,
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
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 output. 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 output, numbered the
same as for
-top.
- -width
-
The number of columns to be in the output. Must be positive.
- -height
-
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.
- -verbose
-
Print information about the processing to Standard Error.
SEE ALSO
pnmcrop(1),
pnmpad(1),
pnmcat(1),
pgmslice(1),
pnm(5)
AUTHOR
Copyright (C) 1989 by Jef Poskanzer.
Index
- NAME
-
- SYNOPSIS
-
- DESCRIPTION
-
- OPTIONS
-
- SEE ALSO
-
- AUTHOR
-
This document was created by
man2html,
using the manual pages.
Time: 19:49:13 GMT, April 27, 2011