ppmtosixel(1)            UNIX System V(26 April 1991)             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.









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