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An accurate approach for calibrating rotational angle of camera

In order to obtain the scene information of a larger or 360 degrees field of view, it is necessary to accurately know the rotational angle of a camera around a fixed axis, which directly affects the quality of point cloud registration and integration. This paper presents a novel rotational angle calibration method by using an extra large viewing-angle camera and high precise checkerboard. The large viewing-angle camera is fixed and has the same imaging direction as the calibrated camera. The checkerboard is placed in front of the two cameras to determine their relative positions. The experimental results show that the error between the actual rotational angle and the calibration result is below 0.0959 degrees. The proposed calibration method can accurately and effectively obtain the rotational angle of a camera.