High precision and fast calibration method of fish-eye camera based on two-dimensional turntable

Abstract

Camera calibration is a prerequisite for spatial position measurement. The fish-eye camera can increase the field of view, but at the same time, the distortion it brings is more serious. It is difficult to obtain high accuracy when using traditional methods to calibrate the fish-eye camera. Therefore, this paper proposes a fast calibration method for fisheye cameras, which makes the calibration process convenient and fast, and improves the calibration accuracy. The camera is fixed on a high-precision two-dimensional turntable, and the turntable rotates according to the set law through a fully automatic program. At the same time, the camera captures the bright spots in the collimator and extracts the pixel coordinates of its centroid. Collect several sets of data, use the bicubic interpolation method to expand the data, find the relationship between the pixel coordinates of the centroid of the bright spot and the rotation angle of the turntable. Finally, the three-dimensional space coordinates can be obtained by binocular vision triangulation to verify the calibration accuracy. The above method bypasses the traditional camera optical imaging model and distortion model, but uses traversal and interpolation. Experiments show that the accuracy of this method can reach the centimeter level in long-distance, large field of view, and severely distorted scenes.