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Large-scale scene calibration method based on non-perpendicular vanishing points

The existing calibration method used in the large-scale scene generally utilizes the perpendicular vanishing points formed by the structured information on the buildings in the scene. Aimed at meeting the situations that no vanishing points exist or the existing vanishing points deviate verticality to a small degree, a two-step calibration method is proposed in this paper. Firstly, we place two designed marker poles in the scene to introduce in a pair of vanishing points and figure out the camera parameters by assuming that the introduced pair of vanishing points are perpendicular, secondly, we construct the error function when the vanishing points are non-perpendicular, and use the worked-out camera parameters as initial values to optimize the error function to obtain the accurate value of the parameters. The simulation and real experiments both show that the method is effective, accurate and robust.