Head tracking and color video acquisition via near infrared luminance keying

A system for detecting and tracking the head location of a user within an area, comprising:

• a rear projection screen located in a position substantially behind the user;
• means for illuminating the rear projection screen with light having a wavelength in the near-infrared spectrum;
• means for projecting a video of a location remote from the user onto the rear projection screen, the projecting means emitting light having a wavelength outside of the near-infrared spectrum;
• and
• a camera unit located in a position substantially in front of the user, the camera unit including a near-infrared camera and a color camera maintained in a stacked relationship with respect to each other, wherein the near-infrared camera detects head location based on luminance differences between the illuminated rear projection screen and a video object in relative proximity to the projection screen.

A head detection and tracking system, comprising:

• a rear projection screen located in a position substantially behind a user;
• an illuminator operative to uniformly illuminate the rear projection screen with light having a wavelength in the near-infrared spectrum;
• a projector operative to project a video image of a location remote from the user onto the rear projection screen, the projector emitting light having a wavelength outside of the near-infrared spectrum;
• and
• a camera unit located in a position substantially in front of the user, the camera unit including a near-infrared camera and a color camera maintained in a stacked relationship with respect to each other, wherein the near-infrared camera detects the head location of the user based on luminance differences between the uniformly illuminated rear projection screen and a video object in relative proximity to the rear projection screen.