PPMTORLE(1) 1 (July 30, 1990) PPMTORLE(1)
NAME
ppmtorle - convert a PBMPLUS/ppm image file into an RLE
image file.
SYNOPSIS
ppmtorle [ -h ] [ -v ] [ -a ] [ -o outfile ] [ infile.ppm ]
DESCRIPTION
This program converts PBMPLUS full-color (ppm) image files
into Utah RLE(5) image files. PBMPLUS/ppm image files
contain the image dimensions and image data in the form of
RGB triplets. When converting to an RLE file, the alpha
channel may be optionally computed. The origins of PBMPLUS
and Utah RLE files are in the upper left and lower left
corners respectively, so this program automatically "flips"
the image. The input can consist of several concatenated
ppm images, in which case, the output will consist of
several concatenated RLE images.
The RLE file will contain a "true color" image (24 bits).
These RLE files may then be viewed using any RLE image
viewer. When they are displayed on an 8 bit display, the
image must be dithered. In order to produce a better
looking image (on 8 bit displays), it is recommended that
the image be quantizing (to 8 bit mapped color) prior to its
display. This may be done by piping the output of this
program into the Utah mcut(1) or rlequant(1) utilities. An
example of this is shown later.
OPTIONS
-v This option will cause ppmtorle to operate in verbose
mode. The header information is written to "stderr".
Actually, there is not much header information stored
in a PBMPLUS file, so this information is minimal.
-h This option allows the header of the PBMPLUS image to
be dumped to "stderr" without converting the file. It
is equivalent to using the -v option except that no
file conversion takes place.
-a This option will cause ppmtorle to use the RGB data to
compute an alpha channel in the resulting RLE file.
For any non-zero RGB data, the alpha channel will
contain a value of 255. The resulting RLE image file
will contain three color channels and an alpha channel.
-o outfile
If specified, the output will be written to this file.
If outfile is "-", or if it is not specified, the
output will be written to the standard output stream.
infile.ppm
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PPMTORLE(1) 1 (July 30, 1990) PPMTORLE(1)
The name of the PBMPLUS image data file to be
converted. This file must end in ".ppm". However, it
is not necessary to supply the ".ppm" extension as it
will be added to the supplied name if not already
there.
EXAMPLES
ppmtorle-v test.ppm -o test.rle
While running in verbose mode, convert test.ppm to RLE
format and store resulting data in test.rle.
ppmtorle test | mcut >test.rle
Convert test.ppm to RLE format and convert to 8 bit
mapped color before storing data in test.rle
ppmtorle-h test
Dump the header information of the PBMPLUS file called
test.ppm.
SEE ALSO
mcut(1), pgmtorle(1), rlequant(1), rletoppm(1), urt(1),
RLE(5).
AUTHOR
Wesley C. Barris
Army High Performance Computing Research Center (AHPCRC)
Minnesota Supercomputer Center, Inc.
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