Abstract: A system is mounted within eyewear or headwear to unobtrusively produce and track reference locations on the surface of one or both eyes of an observer. The system utilizes multiple illumination sources and/or multiple cameras to generate and observe glints from multiple directions. The use of multiple illumination sources and cameras can compensate for the complex, three-dimensional geometry of the head and anatomical variations of the head and eye region that occurs among individuals. The system continuously tracks the initial placement and any slippage of eyewear or headwear. In addition, the use of multiple illumination sources and cameras can maintain high-precision, dynamic eye tracking as an eye moves through its full physiological range. Furthermore, illumination sources placed in the normal line-of-sight of the device wearer increase the accuracy of gaze tracking by producing reference vectors that are close to the visual axis of the device wearer.

Abstract: A scene illumination system is provided that produces spatially uniform or controlled brightness levels for machine vision applications. The system includes a camera, multiple light sources that preferentially illuminate different regions within the camera's field-of-view, and a processing unit coupled to the camera and light sources. Focal regions of the light sources within the camera's field-of-view are sampled to determine average regional brightness and compared to target brightness levels. The processing unit controls the light/sources to increase or decrease illumination levels to converge toward the target brightness levels within the field-of-view. This modulation of the light sources may be repeated with successive video images until target brightness levels are achieved.