You need to have xwallpaper (and therefore also some version of the X window manager) and bash installed.
background-changer.sh <directory> <time>
It takes the images to from <directory>
and displays them in order, waiting <time>
in between.
<time>
can be any time in the format used by the sleep
function on your system takes.
It skips images that are removed from the directory and adds images that are moved into the directory to its cycle.
$ ./background-changer.sh Pictures/background/ 1m
This uses the pictures located in Pictures/background
and changes the background every minute.