NAME
      dvirle - convert dvi version 2 files,
      produced by TeX82, to RLE images

 SYNOPSIS
      dvirle [ -m number ] [ -h ] [ -s ] [ -d number ] [ -x xfilter ] [ -y
      yfilter ] infile.dvi

 DESCRIPTION
      Dvirle converts .dvi files produced by TeX(1)
      to RLE(5) format.  The basic process involves
      two passes.  In the first pass, the .dvi file
      is converted into a list of characters.  The
      second pass takes this list and converts it
      to RLE.  The image is filtered to produce
      gray-scale letters.  300dpi fonts are used,
      producing an unfiltered page size of
      approximately 2500x3500 pixels.  The default
      is to average this by 5 pixels in the X
      direction and 5 in the Y, producing a 510x708
      image.  The filtering parameters can be
      altered with the -x and -y flags.

      The -m number option is used to change the
      device magnification (which is in addition to
      any magnification defined in the TeX source
      file).  Number should be replaced by an
      integer which is 1000 times the magnification
      you want.  for example, -m 1315 would produce
      output magnified to 131.5% of true size.  The
      default is no magnification (1000).  Note,
      however, that a site will only support
      particular magnifications.  If you get error
      messages indicating that fonts are missing
      when using this option, you probably have
      picked an unsupported magnification.

      The -h flag, when supplied, causes the image
      to be converted "on its side" (rotated by 90
      degrees).

      Normally the first pass prints the page
      numbers from the .dvi file.  The -s flag
      suppresses these.

      The default maxdrift parameter is 2 pixels
      (1/100th of an inch); the -d option may be
      used to alter this.  The maxdrift parameter
      determines just how much font spacing is
      allowed to influence character positioning.
      The default value 2 allows a small amount of
      variation within words without allowing any
      letters to become too far out of position.

      The output file contains a number of separate
      RLE images concatenated, one for each page in
      the input.  These can be separated with
      rlesplit(1).  The output images have a single
      image channel and an identical "alpha"
      channel.  For compositing with a colored
      background, it will be necessary to use
      rleswap(1) to expand it to 3 color channels.

      The shell script topcrop will crop off the
      top 384 lines of the output image (assuming
      the default LaTeX page size and dvirle
      filtering parameters), making it suitable for
      viewing on a (384x512) frame buffer.
          topcrop <file.rle >cropfile.rle

      A better solution is to use something like
      the following LaTeX macros to set the page
      size so that, with the default filter
      parameters, the output images will be
      510x384.
      \newcommand{\maxpage}{                  %% Make page as large as possible
                \setlength{\topmargin}{0in}
                \setlength{\oddsidemargin}{0pt}
                \setlength{\evensidemargin}{0pt}
                \setlength{\marginparwidth}{0pt}
                \setlength{\marginparsep}{0pt}
                \setlength{\headheight}{0pt}
                \setlength{\headsep}{0pt}
                \setlength{\textwidth}{6.5in}}
      \newcommand{\plainpage}{                %% Page with space for headers
                \pagestyle{plain}
                \setlength{\textheight}{4.0667in}
                \setlength{\footheight}{12pt}
                \setlength{\footskip}{24pt}
                \maxpage}

      \newcommand{\headingspage}{             %% Page with headers
                \pagestyle{headings}
                \setlength{\textheight}{4.0667in}
                \setlength{\footheight}{12pt}
                \setlength{\footskip}{24pt}
                \maxpage}
      \newcommand{\emptypage}{                %% Page with no headers
                \pagestyle{empty}
                \setlength{\textheight}{4.4in}
                \setlength{\footheight}{0pt}
                \setlength{\footskip}{0pt}


 FILES
      dvirle1    first pass
      dvirle2    second pass

 SEE ALSO
      rleflip(1), rlesplit(1), rleswap(1), urt(1),
      RLE(5).

 AUTHOR
      The original (Versatec) version  was  written
      by   Janet   Incerpi   of  Brown  University.
      Richard  Furuta  and  Carl  Binding  of   the
      University   of   Washington   modified   the
      programs for  DVI  version  2  files.   Chris
      Torek  of  the University of Maryland rewrote
      both passes in order  to  make  them  run  at
      reasonable  speeds.  Spencer W. Thomas of the
      University of Utah converted  it  to  produce
      RLE images as output.

 BUGS
      The -h option  doesn't  work  properly.   Use
      rleflip(1) instead.

      Truncates pages wider than 2550  pixels  (8.5
      inches).

      Doesn't handle missing fonts gracefully.

      Should be a  single  program,  instead  of  a
      shell  script  and two programs.  Doesn't use
      the  usual  RLE  argument   and   file   name
      conventions.   Should  output  the  TeX  page
      numbers as picture comments.














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