Created attachment 8235 
mlterm with img2sixel

Sixel ("six pixels") is a method to show / send pixels (images) using only a terminal. That means, one can show pictures without X11 or Wayland. Old terminals such as mlterm support sixel. Escape codes are used to transmit the pixels.

Recently the libsixel poject is fairly active. Using tools such as img2sixel, one can show images in the console, even when working remotely over ssh.

Practical uses are e.g. when viewing images or pdf attachments in mutt, when using ranger remotely to organize files, and so on. When no X over ssh is available, or when it works very slow, then Sixel is nice to have. If offers far better image quality then other methods, such as the clever chafa program. Tools such as w3m and neofetch can be used with Sixel. Also gnuplot can make use of it, see e.g. here:

https://mintty.github.io/mintty-gnuplot.png

For Windows users, Mintty supports Sixel.

Unfortunately xfce4-terminal does not work with Sixel :-(

Note that the author of kitty has implemented an alternative method which also makes use of Escape codes. See the links below.

As older terminals, such as xterm -ti vt340, mlterm and urxvt can be used with Sixel, and modern ones such as alacritty are planning to implement support, I hope that such an enhancement might bring joy to the xfce4-terminal as well.

References:

- https://github.com/saitoha/libsixel
- https://en.wikipedia.org/wiki/Sixel
- https://github.com/ranger/ranger/wiki/Image-Previews
- https://mintty.github.io/
- https://github.com/jwilm/alacritty/issues/910

Kitty terminal graphics protocol, an alternative:

- https://sw.kovidgoyal.net/kitty/graphics-protocol.html
- https://github.com/kovidgoyal/kitty/issues/33

Also interesting:

- https://hpjansson.org/chafa/