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)