Is it possible to export the current iPhone wallpaper?

I have a photo set as my current iPhone wallpaper, which I would like to save. I have forgotten where I stored this file on my computer originally, so I can't easily go back to place it back on my phone. It has since been deleted from my camera roll.

Is there any way to export the photo that is currently set as the wallpaper, so that I can change the wallpaper to something else, but save the other one?

You cannot export the wallpaper, depending on the pattern (if it were repetitive) it would be possible to take screen shots and after emailing these to your self you could edit in Photoshop (other editing software is available)

You would need to take one shot of a page in iOS with only one app, and then if it is a repeatable patern you can edit out or clone out the app on the screen and the apps at the bottom.

Alternatively you can or tap and hold an app to get to wiggle mode, and go to the far right to get a "clean" page, then screenshot this.

Not great but that is the only way, I'm afraid.

As an expansion to Macjack's answer, here's the process I just followed to retrieve the lock screen wallpaper on my phone.

Looking in the /Users/<youruser>/Library/Application Support/MobileSync/Backups folder is effective but very time consuming, especially if you have a lot of files/images in your backup (my phone a 16GB iPhone 5 that is pretty full had nearly 7000 files in there). However, the majority of them were not photos for me.

So I wrote a small script to extract the photos and rename them so they have the proper file extension. This makes it possible to use the image carousel preview for reviewing the images quickly.

Get the script here. (right click and 'Save link as' and save into your Downloads folder)

Now, open Terminal (type 'terminal' into spotlight). Then copy and paste this into the terminal window:

cd ~/Library/'Application Support'/MobileSync/Backups
chmod +x ~/Downloads/img-separator.sh
BACKUP=$(ls -t . | head -n1)
~/Downloads/img-separator.sh "$BACKUP"

What those four lines do, for non-programmers:

1. "moves" you into the Backups directory
2. Makes the script I wrote above "executable" (able to be run)
3. Gets the name of the newest backup
4. Runs my script, telling it the name of the backup to process

And here is a description of what the script does.