Quote I am reading a book to my Grandson, and editting it in CyberStudio. Basically, the "video" feed is a series of PNG and JPG files of pages that are stretched to cover the appropriate period in the audio track corresponding to those pages. I wanted to add a page turning transition between those pages. The program will not allow it, probably because it expects video, or keyframes or something.
What to I need to do to have transitions between image files?

It is not clear from the post whether you have a video or still images on the timeline. If they are images then it should be easy to add the cross behavior page curl transition between each image.

If You have a video instead then split it in sections where the next slide in the video starts. You can then add the same type transition as you would for the images. An alternative would be to create a snapshot of each slide and place them with the correct duration on a lower track. Set the opacity to 50% so you can see and position them with the correct duration. Set the opacity back to 100% to finish.