How do I file a png image in the appropriate folder to have as choice for wallpaper?

[Shabakthanai]

In the root folders, I found a folder in /usr/share/wallpapers that appears to store the wallpapers for Kubuntu 13.10. I have an image that I have used as wallpaper for the login screen, the splash screen that appears next on screen, and the Desktop. It appears when I boot on the Login Screen, but not the other two. I have attempted to move a 1920 x 1080, which is the same for both monitors, but am unable to make the transfer. I tried drag and drop and cut and paste, neither made the trip. I also opened Dolphin in super user state using kdesudo Dolphin, and still the transfer would not work. What am I doing wrong?

Sometimes too much time passes between when I do something until the next time I need the same result. I seem to be unable to retain the needed skill. Thanks for any help.

By the way, are the images for splash-screen, login-screen and desktop-background, stored in the same location?

I attempted to find the appropriate folder in the hidden files, but couldn't find it. Any ideas at all? Thanks!

[oshunluvr]

You are not root, therefore you cannot move a wallpaper to a root owned directory. Either launch dolphin as root:

kdesudo dolphin

or just leave the wallpaper where it is and select it for your desktop. Right click on the desktop, select "Default Desktop Settings" and click the "Open" button. Then navigate to the desired image.