Shell Script for automating background images in linux works both with url as well as downloaded imagesgsettings
point the shell script using arguments(script.sh url ) to the url image you want to get the shell script will download and resize it using imagemagick to best suit the current dimentions of your home screen (multiple images from url not implemented)
Point the script to the directory(script.sh Loc ) in which the image is located and the script will randonly get the images from there and display it
1.PUT ALL THE IMAGES U WANT INTO ONE FOLDER
2. Give the parameters accordingly
its that simple
Note
to get better results add it to a cronjob of the system