An interesting and practical example of computational photography from CMU. An example of projector/cameras (PROCAM) system
A camera senses oncoming cars, falling precipitation and other objects of interest, such as road signs. The one million light beams can then be adjusted accordingly, some dimmed to spare the eyes of oncoming drivers, while others might be brightened to highlight street signs or the traffic lane. The changes in overall illumination are minor, however, and generally not noticeable by the driver.