mhsetroot
wallpaper setting untility has frontend gmhsetroot on SF
... any size you want center screen, vertically, horizontally, diagonally.
Flip the monitor screen separately either vertically, horizontally, diagonally.
Flip them both at the same time in opposing angles for some really cools effects.
Set the background color with two separate colors w/ gradient for added eye candy.
Set the image full screen, center, fill, and tile all at original image size.
..and More