Abstract: In applications where it is desired to determine the locations of image features, such as eye monitoring to determine the direction that a person is gazing, determining the point at which he is gazing, or measuring the motions of his eye using a camera to capture an optical image of the eye and image processing to extract information about the eye's gaze point and/or orientation, there is provided a method and apparatus for precise location of image features such as edge coordinates between the pupil anc iris of the eye and of the center coordinates of light reflections off the cornea of the eye.

Abstract: It is sometimes required to track randomly moving objects with precision and high speed. This inventioin pertains to a mirro rotation assembly that provides precise, high-speed pitch and yaw tracking by rotating a low-moment-of-inertia mirror rather than rotating a heavier double gimballed mirror assembly or the camera-lens assembly itself. By pivoting the mirror on a single bearing point and controlling the mirror surface pitch and yaw by driving two mirror tie points along circumferential paths around the bearing point, a low moment of inertia is obtained. The low moment of inertia together with mirror velocity rather than position control permits higher speed tracking while maintaining the required precision. The velocity control strategy minimizes image blur resulting from unpredicted object motions.

Abstract: A system for focussing a lens on a point light source is provided that includes an opaque member disposed near the lens. The member cast a shadow having a distinguishable orientation in the image of the light source. An image processing device determines the focus condition and range to the point light source from the orientation and size of the shadow.