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Method for out-of-focus camera calibration
Journal article   Peer reviewed

Method for out-of-focus camera calibration

Tyler Bell, Jing Xu and Song Zhang
Applied optics. Optical technology and biomedical optics, Vol.55(9), pp.2346-2352
03/20/2016
DOI: 10.1364/AO.55.002346
PMID: 27140572

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Abstract

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.

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