I have some upcoming shoots where we'll have wide shots with a person carrying a cell phone. The idea is to have a set of icons floating above the phone that follow its movement. If we have the person travel across the screen — say from left to right — I figure a simple 2D track can handle that since there won't be any significant Z axis movement.
However, it would be nice to have the person approach the camera from a distance and have the track still work. Any suggestions on how to effect this? I've thought of perhaps having the actor wear clothing with distinctive patterns or jewelry that stands out a bit so that I can do object tracking on those and offset to approximate the location of the phone. The person will be in business clothes which makes it just a bit more challenging. I've also considered attaching a few LEDs to the phone.
If the shot were a close-up I'd go the normal route of putting the usual trackers on the phone. Given the distance from the camera, I don't know if that's going to help much and whether it would be possible to derive much in the way of orientation and scale information.