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PPMTORLE(1)            DragonFly General Commands Manual           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
              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.

1                                July 30, 1990                     PPMTORLE(1)

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