Proximity based trigger of photos/videos

I'm basically working on a patch that will transition from one photo/video to another based on distance from a proximity sensor.

I have the proximity sensors dialed and reporting back distance information fine. I've been able to trigger audio/video events based on distance.

What I want to do now is have a different image load (crossfading from last image) when a certain distance increment is crossed. So: Person is 100" away from sensor show image 1, person is 90" from sensor show image 2, and so on. Preferable with a cross fade between images.

Another idea was to make the images a video clip and have the persons proximity scrub through the video at a certain speed.

Has anyone done anything similar or have any ideas?

Thanks!