How to Change Login Background in Ubuntu 12.04

Changing the desktop background is easy and probably everyone has already done it. What about tweaking your machine even further to your liking? What about changing the background of the LOGIN screen? Let's do it!

By default, Ubuntu 12.04 uses the following file as its login background,

/usr/share/backgrounds/warty-final-ubuntu.png

To change this  default background what one can do is to do a backup of this original image and copy your background here with the same name. Probably not the most elegant solution, but it serves its purpose.

1. Make a backup of the original image
   

   sudo mv /usr/share/backgrounds/warty-final-ubuntu.png /usr/share/backgrounds/warty-final-ubuntu_backup.png

2. Copy the image you want to use as background
   

   sudo cp ~/MyBackground.png /usr/share/backgrounds/warty-final-ubuntu.png

   Where "MyBackground.png" is the image you want to set as login background. Use absolute paths for copying, that is /home/user/......
   
3. Reboot or relog to your your system to be welcome by the new login background.

Note:

If you wish to undo the changes or simply use another background picture for the login screen, simply copy back either the original image or the new one you like.

• The background of your selection must be a *.png file, matching screen size.
• The name has to be warty-final-ubuntu.png