ppmtosixel(1)                                       ppmtosixel(1)

       ppmtosixel - convert a portable pixmap into DEC sixel for-

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

       Reads a portable pixmap as input.  Produces sixel commands
       (SIX) as output.  The output is formatted for color print-
       ing, 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.

       -raw   If  specified,  each  pixel  will   be   explicitly
              described in the image file.  If -raw is not speci-
              fied, 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.

              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.

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

       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.


       Copyright (C) 1991 by Rick Vinci.

                          26 April 1991                         1