Simple object tracking prototypes in one and two dimensions using a cheap webcam. The tracking data is used to control the state of an LED array (via USB connection to an Arduino which manages the LED driver).
The eventual goal from this project is to develop a cheap, robust, system for tracking multiple people as they move through a space, allowing the room to react to their presence and movement. Essentially, to provide an easy and cost-effective means for developing installations like this one, which tend to be quite expensive to produce. To keep the cost as low as possible these early prototypes used the cheapest USB webcam I was able to find, which wound up costing less than the circuitry needed to control the LEDs. For a large-scale installation, the cost of LED controllers, lights, etc., easily outstrips the cost of the cameras, so future prototypes will use RGB-D sensors which allow for much more accurate object detection and tracking than a normal webcam.
The cost of driver chips, however, is non-negligible for a project large enough to fill a room. The cheaper drivers tend to only come in surface-mount packages, so prototyping is going a little slowly as I make breakout boards to use in testing. I'm currently focusing on using the TLC5947 driver for LED arrays, which seems to be quite cost-effective.