crop a portable anymap
see also :
pnmcut - pnmfile
[-right] [-top] [-bottom]
All options may
be abbreviated to their shortest unique prefix or specified
with double hyphens.
add an example, a script, a trick and tips
ps2ppm.sh < $base.ps |
pnmcrop > $base.ppm__
pnmpaste $base.ppm__ 0 0 $base.ppm_ | pnmcrop > $base.ppm
convert $base.ppm sgi:$base.rgb
( pngtopnm < "$1" | pnmcrop | ppmchange black white white
black | pnmtopng -transparent black > "$1".tmp ) 2>/dev/null
#( pngtopnm < "$1" | pnmcrop |
pnmtopng -transparent white > "$1".tmp ) 2>/dev/null
date >> $LOGFILE
( pngtopnm < "$1" | pnmcrop | pnmtopng -transparent white >
>> $LOGFILE 2>&1
pnmcrop < $1.ppm | ppmtogif
Reads a PBM,
PGM, or PPM image as input. Removes borders that are the
background color, and produces the same type of image as
don’t specify otherwise, pnmcrop assumes the
background color is whatever color the top left and right
corners of the image are and if they are different colors,
something midway between them. You can specify that the
background is white or black with the -white and
-black options or make pnmcrop base its guess
on all four corners instead of just two with
pnmcrop chops off any stripe of background color it
finds, on all four sides. You can tell pnmcrop to
remove only specific borders with the -left,
-right, -top, and -bottom options.
If you want to
chop a specific amount off the side of an image, use
If you want to
add different borders after removing the existing ones, use
pnmcat or pnmcomp.
Take white to be the background
color. pnmcrop removes borders which are white.
Take black to be the background color. pnmcrop
removes borders which are black.
Determine the background color from the colors of the
four corners of the input image. pnmcrop removes
borders which are of the background color.
If at least
three of the four corners are the same color, pnmcrop
takes that as the background color. If not, pnmcrop
looks for two corners of the same color in the following
order, taking the first found as the background color: top,
left, right, bottom. If all four corners are different
colors, pnmcrop assumes an average of the four colors
as the background color.
-sides option slows pnmcrop down, as it reads
the entire image to determine the background color in
addition to the up to three times that it would read it
Remove any left border.
Remove any right border.
Remove any top border.
Remove any bottom border.
Print on Standard Error
information about the processing, including exactly how much
is being cropped off of which sides.
pnmfile , pnm
1989 by Jef Poskanzer.