Can I Change the Wallpaper shown on my Samsung Galaxy S III?
Choose what you see on the Home screen (behind your shortcuts and widgets) and what you see on your device's lock screen.
Changing the Wallpaper
From the Home screen, touch Menu > Set wallpaper.
Select Home screen, Lock screen, or Home and lock screens, and choose from:
Gallery: Select a wallpaper from pictures you have taken with your camera or uploaded to your device.
Live wallpapers: Select an animated wallpaper. Not available if Lock screen is selected. Note: Using animated Live Wallpapers can deplete your battery faster than image wallpapers.
Wallpapers: Select from many still-life preloaded and downloaded wallpapers.
Photos: Select a wallpaper from photos stored in Google™ Photos. Available only when Home screen is selected.
Select a wallpaper and touch Done or Set wallpaper.