We get it. You imported some photos and then decided that they must never, ever appear in one of your books. Or perhaps you just want to stay organized. In any case, here's how to delete photos from your book project's photo library.
Oh, and don't worry, BookSmart makes its own copies of images you load into the program. Deleting an undesired picture from BookSmart will not remove the source JPG or PNG from your computer.
In your book project, make sure "My Photos" is visible and expanded on the left side of your BookSmart screen.
Select the images that you want to delete by clicking on them. Remember: You can select many pictures at a time by holding down the Shift key and clicking. Hit the Delete key on your keyboard or right-click and select delete.
If you've finished placing all pictures on your pages and you want to reduce your file size to save disk space, you can remove all unused images. Simply use the filter to show only Unused Photos, then highlight and delete those images.
Please note: iPhoto images can not be deleted from your BookSmart image library, but you can use the Filter menu to hide all or some of them.