This is just a very simple technique, and a one click thing. But it will be useful from time to time.
Sometimes, you face this when you are scanning your pictures, taking pictures from an uneven ground or even some stranger taking your picture may end up like this.
All you need is a photoshop CS2 or CS3. If you can do that with an older version, let me know.
Now you just have to do the following:-
- File > Automate > Crop and Straighten Photos
- You may want to crop some of the mess or whitespot.
Source for this Straighten Pictures Tutorial
