As you may already know, Ubuntu 12.10 (Quantal Quetzal) changes your login screen image based on your desktop backgrounds. So, whatever image you set as your default desktop wallpaper is also be applied to your login screen.
If you don’t want your login screen to carry the same desktop wallpaper, you can follow the tutorial below to change that. It’s easy to change.
- Change Ubuntu 12.10 Login Image
To get stated, press Ctrl – Alt – T on your keyboard to open the terminal. When it opens, run the command.
Next, run the commands below to create connection to the X server as lightdmxhost +SI:localuser:lightdm
Then run the command below to assume and run scripts as lightdm.su lightdm -s /bin/bash
Next, run the commands below to disable dynamic background switching.gsettings set com.canonical.unity-greeter draw-user-backgrounds 'false'
Finally, run the commands below to add the image your wish to show up on the login screen. You must replace the path-to-image with the correct path to the image stored on your computer.gsettings set com.canonical.unity-greeter background '/path-to-image.png'
Restart / Login and enjoy!
To remove the dotted-lines added by Ubuntu, run the commands below.gsettings set com.canonical.unity-greeter draw-grid 'false'