In slide animation!
I am looking for a way to 'modify' images in themselves during a show. EG as an extreme example, alter the image from positive to negative (before making a transition). I can do a transition from one image to the next using two images but more gradual changes within the image itself do not seem possible. (I could make lots if layers in photoshop but I think the changes would be too slow.) Being able to make 'in-image' changes could open up many visual possibilities.