Navigating and selecting a portion of a screen by utilizing a state of an object as viewed by a camera

A computer system is described including a camera, a display device (e.g., a display monitor) having a display screen, and a processing system coupled to the camera and the display device. The camera produces image signals representing one or more images of an object under the control of a user. The processing system receives the image signals, and uses the image signals to determine a state of the object. The state of the object may be, for example, a position of the object, an orientation of the object, or motion of the object. Dependent upon the state of the object, the processing system controls cursor movement and selection of a selectable item at a current cursor location. The object may be a body part of the user, such as a face, a hand, or a foot. The object may also be a prominent feature of a body part, such as a nose, a corner of a mouth, a corner of an eye, a finger, a knuckle, or a toe. The object may also be an object held by, attached to, or worn by the user. The object may be selected by the user or selected automatically by the processing system. Multiple images may be chronologically ordered with respect to one another.