A curious project presented at SIGGRAPH: it's called Instant replay and it's done by folks from Mitsubishi Electric Research Laboratories (MERL).

Real-world, slow-motion instant replay for air hockey. This new space-labeling technology tracks the pucks with a high degree of accuracy and speed (1cm/500Hz) in natural illumination without visible tags.

This system uses infrared optical data projection and hardware tags to provide tracking data for many objects that are moving and rotating very quickly. Because the tags are very inexpensive, many of them can be deployed in harsh conditions.

The core technical innovation of this work is the system's space-labeling technology. The projectors are inexpensive, solid-state, high-speed devices that project invisible (infrared) patterns 10,000 times a second. By sensing 20 patterns (1/500th of a second), passive tags are able to decode their own location. Because the entire space is labeled, the speed of the system remains constant no matter how many tags are tracked. The tags use very inexpensive, off-the-shelf IR-decoding modules and microcontrollers. The projectors are also very inexpensive. In addition to decoding their location, the tags have the ability to detect their orientation and record incident illumination.

Why do I blog this? yet another location detection technology (just keeping track of stuff).