Method for out of focus camera calibration.
State of the art camera calibration methods assume that the camera is at least nearly in focus and thus fail if the camera is substantially defocused. This paper presents a method which enables the accurate calibration of an out of focus camera. Specifically, the proposed method uses a digital display (e.g. liquid crystal display monitor) to generate fringe patterns that encode feature points into the carrier phase; these feature points can be accurately recovered, even if the fringe patterns are substantially blurred (i.e. the camera is substantially defocused) Experiments demonstrated that the proposed method can accurately calibrate a camera regardless of the amount of defocusing: the focal length difference is approximately 0.2% when the camera is focused compared to when the camera is substantially defocused.
Applied optics