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ppmtosixel(1)


NAME

   ppmtosixel - convert a portable pixmap into DEC sixel format

SYNOPSIS

   ppmtosixel [-raw] [-margin] [ppmfile]

DESCRIPTION

   Reads  a  portable  pixmap  as input.  Produces sixel commands (SIX) as
   output.  The output is formatted for color printing,  e.g.  for  a  DEC
   LJ250 color inkjet printer.

   If  RGB values from the PPM file do not have maxval=100, the RGB values
   are rescaled.  A printer control header and a  color  assignment  table
   begin  the  SIX  file.  Image data is written in a compressed format by
   default.  A printer control footer ends the image file.

OPTIONS

   -raw   If specified, each pixel will be  explicitly  described  in  the
          image  file.   If  -raw is not specified, output will default to
          compressed  format  in  which  identical  adjacent  pixels   are
          replaced  by  "repeat  pixel"  commands.  A raw file is often an
          order of magnitude larger than a compressed file and prints much
          slower.

   -margin
          If -margin is not specified, the image will be start at the left
          margin (of the window,  paper,  or  whatever).   If  -margin  is
          specified, a 1.5 inch left margin will offset the image.

PRINTING

   Generally,  sixel files must reach the printer unfiltered.  Use the lpr
   -x option or cat filename > /dev/tty0?.

BUGS

   Upon rescaling, truncation of the least significant bits of RGB  values
   may  result  in  poor color conversion.  If the original PPM maxval was
   greater than 100, rescaling also reduces the image  depth.   While  the
   actual  RGB  values  from  the  ppm file are more or less retained, the
   color palette of the LJ250 may not match the  colors  on  your  screen.
   This seems to be a printer limitation.

SEE ALSO

   ppm(5)

AUTHOR

   Copyright (C) 1991 by Rick Vinci.

                             26 April 1991                   ppmtosixel(1)



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