Yeah sixels look really nice. I usually use gnome-terminal which doesn't seem to support it, which is why I never really built sixel for myself in the first place. But it looks worthwhile to build support in for it.
Considering I already have a framework to support both Braille and normal ASCII art, I think it should be possible to work in sixel support with graceful fallback to Unicode and ASCII. I think the way I have it set up, only the termgraphics library would need to be changed, without needing to change the visualization logic.
Your post made me create an account to respond to you and upload a few screenshots of what I use along with binaries. Check github.com/csdvrx/sixel-gnuplot - you will see it's not just nice but also super practical.
apt-get install mlterm and you're done!
For fallback, I agree: a braille support in gnuplot would be great when sixel support is not available.
Interesting. Just tried that. It works, but it seems like it doesn't support a lot of Unicode (including Chinese which is my system language and used in a lot of my text files) so it's kind of a deal-breaker to use on a day to day basis.
If gnome-terminal and other mainstream terminals supported sixel though that would be really amazing.
Nevertheless though it would be nice to build support into ROSshow for sixel since it's not that difficult to launch mlterm just for ROS visualizations, and for people who use English only, and in hopes that gnome-terminal will support it one day.
I use the following with mintty on windows: (or mlterm on linux)
#!/bin/bash
export GNUTERM="sixelgd size 1280 720 truecolor font arial 10"
gnuplot-nox -e "set title '$HOST'; plot '<cat'"
Then it's just cat something | '{ print $5}' | tail -n +500 | sixel-plot.sh
I put an example with a screenshot and recompiled gnuplot binaries (debian) on http://github.com/csdvrx/sixel-gnuplot