pysixel

What is SIXEL?

SIXEL is one of image formats for terminal imaging introduced by DEC VT series. SIXEL image data scheme is represented as a terminal-friendly escape sequence. So if you want to show a SIXEL image file, all you have to do is "cat" it to your terminal.

See also more faster high quality C implementation libsixel: https://github.com/saitoha/libsixel

I heard SIXEL was supported by some old terminal applications, such as SAS, WordPerfect.

Nowadays netpbm and Gnuplot support this.

Requirements

If you want to view a SIXEL image, you have to get a terminal which support sixel graphics.

Now SIXEL feature is supported by the following terminals.

RLogin (Japanese terminal emulator)

http://nanno.dip.jp/softlib/man/rlogin/
tanasinn (Works with firefox)

http://github.com/saitoha/tanasinn/
mlterm

Works on each of X, win32/cygwin, framebuffer version. http://mlterm.sourceforge.net/
XTerm (compiled with --enable-sixel option) You should launch xterm with "-ti 340" option. the SIXEL palette is limited to a maximum of 16 colors. http://invisible-island.net/xterm/
DECterm
Kermit
WRQ Reflection
ZSTEM

Install

via github

$ git clone https://github.com/saitoha/PySixel.git
$ cd pysixel
$ python setup.py install

or via pip

$ pip install PySixel

Usage

PySixel provides a Command line tool:

$ sixelconv [options] filename

$ cat filename | sixelconv [options]

Options:

-h, --help                                            show this help message and exit
-8, --8bit-mode                                       Generate a sixel image for 8bit terminal or printer
-7, --7bit-mode                                       Generate a sixel image for 7bit terminal or printer
-r, --relative-position                               Treat specified position as relative one
-a, --absolute-position                               Treat specified position as absolute one
-x LEFT, --left=LEFT                                  Left position in cell size, or pixel size with unit 'px'
-y TOP, --top=TOP                                     Top position in cell size, or pixel size with unit 'px'
-w WIDTH, --width=WIDTH                               Width in cell size, or pixel size with unit 'px'
-e HEIGHT, --height=HEIGHT                            Height in cell size, or pixel size with unit 'px'
-t ALPHATHRESHOLD, --alpha-threshold=ALPHATHRESHOLD   Alpha threshold for PNG-to-SIXEL image conversion
-c, --chromakey                                       Enable auto chroma key processing
-n NCOLOR, --ncolor=NCOLOR                            Specify number of colors
-b, --body-only                                       Output sixel without header and DCS envelope
-f, --fast                                            The speed priority mode (default)
-s, --size                                            The size priority mode

Example

View an image file:

$ sixelconv test.png

Generate sixel file from an image file:

$ sixelconv < test.png > test.six

View generated sixel file:

$ cat test.six

Show sixel in xterm

$ curl ftp://invisible-island.net/xterm/xterm-301.tgz | tar xz
$ cd xterm-301
$ ./configure --enable-wide-chars --enable-sixel-graphics --enable-256-color
$ make
# make install
$ xterm -ti vt340 -e 'sixelconv -n16 ~/testdir/test.jpg'

Code Example

import sixel
writer = sixel.SixelWriter()
writer.draw('test.png')

Dependency

Pillow https://github.com/python-imaging/Pillow

Python imageloader module https://pypi.python.org/pypi/imageloader

Contributors

@cocuh (Python3 support)

Reference

Chris_F_Chiesa, 1990 : All About SIXELs ftp://ftp.cs.utk.edu/pub/shuford/terminal/all_about_sixels.txt

Netpbm http://netpbm.sourceforge.net/

It includes ppmtosixel command http://netpbm.sourceforge.net/doc/ppmtosixel.html

vt100.net http://vt100.net/