[abcdef123xyz]

You can try the sixel branch in tmux - the top of the branch does some conversion and scaling (currently fits image to the pane and scales to the terminal xpixel/ypixel) so it might interfere too much but if you just took b34111b3 and d2e3f3c1 you would have plain passthrough (I might make a separate branch for that actually).

There is still a lot of work to do, I haven't decided if the best option would be to store all images in a big list and draw them separately when needed, or whether to mark the cells they cover and draw the SIXEL when the cell is drawn. SIXEL seems to have some strange behaviours and xterm seems to have a few bugs so I'm not sure how close to emulate everything - it might be better just to do it a sensible way. I don't think many applications will rely on being able to draw on top of SIXELs or have partial characters appear underneath.

I couldn't get img2sixel to generate the right colours, but convert from ImageMagick worked.