PPMTORLE(1)                                         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 ori-
       gins of PBMPLUS and Utah RLE files  are   in  the  upper
       left  and  lower left corners respectively, so this pro-
       gram 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 dis-
       play, the image must be dithered.  In order to produce a
       better  looking  image (on 8 bit displays), it is recom-
       mended 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 result-
              ing RLE image file will contain three color chan-
              nels and an alpha channel.

       -o outfile
              If  specified, the output will be written to this
              file.  If outfile is "-", or if it is not  speci-
              fied,  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".  How-
              ever, 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)
