If you try to close a Microsoft Office application when you've got a ton of its stuff on the clipboard (e.g. a whole word doc), it prompts you to ask if you would like to access that data after the application is closed.
In this day and age, does it really matter if I have say 10MB of stuff on the clipboard?
As I write my image processing app, should I follow the same rule as Office, or just forget about it and leave the data there?