Wallpaper Auto Change Version 1.0.0 Wallpaper config file generator for ubuntu usage: wac -i[input directory] -o[output file] [-r] -k[keep time] -t[tran time] [input directory] Directory where to scan the photo files [output file] Generated config file [keep time] how long to keep a wall paper, in seconds [tran time] duration to change another wall paper, in seconds Wall paper config file in Ubuntu is at (1)[/usr/share/backgrounds/contest] and (2)[/usr/share/gnome-background-properties], put the generated config file to (1), and make a wallpaper config file at (2) which refers to the generated config file at (1). Finally goto Ubuntu Settings - Background and select the wallpaper config with the name you just set at (2).