Comix is a manga type viewer that works a bit like irfanview. Originally, I started using feh, which works from the command line but Comix seemed to meet my needs.
For Ubuntu 20.04 - MComix is a clone of Comix
Ubuntu has a command line image viewer called feh. Use apt-get to install it.
It has some basic commands, use the arrow keys to cycle through pictures, the v key to toggle to full screen.
[Shift]+[<] or [>] to rotate a picture
[Esc] or [Q] to quite