I've been asked to design a system which will reliably track a person walking back and forth across a room, and move a video projector back and forth so that the center of the projected image is (more or less) located on the center of the person's body.

It's for a Modern Dance installation.

Picture a video projector mounted on the head of a standard photographic tripod and you'll have a good idea of what I have in mind.

The projector will have to pan back and forth over a 100 degree arc, but won't need to tilt up or down. Control will be via geared steppers & position sensors, or plain servomotors. And trapezoidal accelleration curves and all that.

I've considered having the performer wear a bracelet or belt containing several high-powered IR LEDs. I could then mount a generic video camera on top of the projector so that they move together. An IR filter on the front of the camera would let me only 'see' the bright spot.

If I can capture the video signal 5-10x per second and break it down to it's basic pixel elements, I can then send pan the projector back and forth until the captured hot spot matches the 'x = halfway' position in the pixel matrix.

Thus, the center of the projected image will more or less match the X position of the dancer's belt/bracelet.

What am I missing? Is there an easier way to do this?

Thoughts?

John