NAME

       ppmtosixel - convert a PPM image to DEC sixel format

SYNOPSIS

       ppmtosixel

       [-raw]

       [-margin]

       [-7bit]

       [ppmfile]

DESCRIPTION

       This program is part of Netpbm(1).

       ppmtosixel  reads  a  PPM image as input and produces sixel commands (SIX) as output.  The
       output is formatted for color printing (e.g. for a DEC LJ250 color inkjet printer) or  for
       color display on DEC VT terminals and terminal emulators (VT240 and beyond).

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

OPTIONS

       In addition to the options common to all programs based on libnetpbm (most notably -quiet,
       see
        Common Options ⟨index.html#commonoptions⟩ ), ppmtosixel recognizes the following  command
       line options:

       -raw   If you specify this, 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 you don't specify -margin, the image will start  at  the  left  margin  (of  the
              window,  paper,  or  whatever).   If you do specify -margin, a 1.5 inch left margin
              will offset the image.

       -7bit  If you don't specify -7bit, each control code will be expressed as a single,  8-bit
              "C1" character.  If you do specify -7bit, each control code will be expressed using
              two,   7-bit    "C0"    characters.     (See    C0    and    C1    control    codes
              ⟨https://en.wikipedia.org/wiki/C0_and_C1_control_codes⟩  for more information.)  In
              other words, -7bit produces more portable sixel files,  and  its  absence  produces
              smaller sixel files.

              This option was new in Netpbm 11.04 (September 2023).

PRINTING

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

LIMITATIONS

       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(1)

AUTHOR

       Copyright (C) 1991 by Rick Vinci.

DOCUMENT SOURCE

       This manual page was generated by the Netpbm tool 'makeman' from HTML source.  The  master
       documentation is at

              http://netpbm.sourceforge.net/doc/ppmtosixel.html