FotoAlbum maintains a backup of any image that is modified. This includes any rotations, flipping or EXIF updates that are done. Backups are not made before any external tools are used. If you want to ensure that original images are maintained when using external tools, be sure to save the file as a different filename when using the tool.
To restore an image to the original state (before any modifications), select the image(s) and choose the "Edit->Revert to original" menu option. This will overwrite any changes you made to these file(s). If you have done a lot of modifications to the file using external tools, be careful when using this option.
Note: Only one copy of an image is ever maintained. It is the original file before any changes were made. If multiple modifications are made, only the first (original) backup is kept. Backups are not made everytime a modification is made.