DVIRLE(1)                                             DVIRLE(1)





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  con-
       verts 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 magni-
       fication (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  magnifi-
       cation  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  unsup-
       ported magnification.

       The  -h flag, when supplied, causes the image to be con-
       verted "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 suit-
       able 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}
                 \maxpage}

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.



1                         May 12, 1987                DVIRLE(1)
