1. A gesture recognition interface system comprising: a first IR light source and a second IR light source positioned to illuminate a retroreflective background surface; a first IR filtered camera operative to receive a first plurality of images based on a first reflected light contrast difference between the retroreflective background surface and a sensorless input object caused by the first IR light source and a second IR filtered camera operative to receive a second plurality of images based on a second reflected light contrast difference between the retroreflective background surface and the sensorless input object caused by the second IR light source, the first and second pluralities of images being respective silhouette images of the sensorless input object; and a controller operative to determine a given input gesture based on changes in relative locations of the sensorless input object in the first plurality of images and the second plurality of images, and being further operative to initiate a device input associated with the given input gesture.