I got simple way to get the ubuntu version name to display on my desktop background.
For this I dont have to edit any wallpaper in Graphics Editor.Just installed the SLIDEWALL application.
Here is the link about it SLIDEWALL APPLICATION

After installing the application i just gone through the codes how it works which is in /opt/extras.ubuntu.com/slidwall

Even the config file is in /home//.local/share/slidewall

What I have done is in /home//.local/share/slidewall/live created a folder name ubuntudsk and pasted the wallpaper i wanted.

then little editing done in gimp and created a logo of same wallpaper size with foreground layer transparent. and pasted this logo file in same folder.

you should look out the /home//.local/share/slidewall/live/ folder and see the clock.ini file in it. Wallpaper should be of same exact size and logo file too.

you should created alike the same other folder of your own and create the same logo file with different name as it count in the copied folder.

What is done the app looks for the particular time,day,date image_name and paste it on wallpaper in it. So I have created as many as logo file with different file name and pasted over there.

So now whenever date,time,day change it just draws the same logo image on my background.

Try it.Below is how it works

BEFORE EDITING SLIDEWALL it looks like

AFTER EDITING SLIDEWALL i got what i want