High-color sixel images don't work on many terminals

[j4james]

Describe the bug

In PR dylanaraps/neofetch#2316, the img2sixel converter was changed to use the -I high-color option. This can sometimes produce better quality images, but it's a non-standard extension which quite a few terminals don't support.

These are some of the terminals that won't always work correctly with the -I option: XTerm, Konsole, Rio, Mintty, Windows Terminal, Alacritty, St, Rxvt, and the vte library (the last four don't have Sixel by default, but it's available via a fork or patch).

On low-color images the issue may not be noticeable, but on high-color images it can result in the output being totally corrupted.

• Does this issue still occur in the master branch? YES

Expected behavior

Ideally the Sixel support should work on all Sixel-capable terminals, and not just those that support the high-color extension.

Screenshots

This is an example of how an image can be corrupted with the -I option:

And this is the same image without the -I option:

Config file

conf.txt

[j4james]

If there's a demand for it, perhaps there could be a separate hisixel backend that calls img2sixel with the -I option, and the default sixel backend could go back to its original configuration without the -I option.

[Neo-Desktop]

I think the idea of a hisixel backend would be a good option as I've currently run into this issue with a chosen image paired with windows terminal.