I wanted to display images each with one or more pan / zoom shots. Both on Windows and Linux. I have a Zbox running Linux Mint that I use as a photo frame. As I looked around for programs, all of them created movies. I did a test with one of these programs and 5 slides took 2 minutes to render the 100MB video. This means that a slide show of 300 slides would take 5 hours to render a movie of 8GB. The images for this slide show are only about 200MB.
QtSlidePlayer allows building slide shows in a portable way and the program runs on either Windows or Linux. You can find the program at SourceForge.