Ppmtosixel User Manual(0) Ppmtosixel User Manual(0)
ppmtosixel - convert a PPM image to DEC sixel format
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.
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.
-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
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.
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.
netpbm documentation 26 April 1991 Ppmtosixel User Manual(0)
Man(1) output converted with