How may I quit iPhoto without saving modifications? I am working with a huge photo library and from time to time I experiment quick editing on some pictures. Sometimes I also make uncontrolled changes which apply on a set of pictures I can't correctly see.

In these situations I would like to be able to exit iPhoto without saving these unwanted modifications.

I didn't find any preference permetting to achieve this wanted behaviour. Hopefully I have this basic function on most applications which can modify files or libraries beyond what the user can see.

Is there any hidden defaults of iPhoto which would give access to such a simple function?

I am actually running iPhoto '11, but I'm interested by this function for any version running on Lion, Mountain Lion &amp; Mavericks.
From the menu at the top select "Photos > Revert to Original".

This also works if you select multiple photos/events.