Camera self-calibration method based on two vanishing points

Abstract

The present invention discloses a camera self-calibration method based on two vanishing points. With two groups of orthogonal parallel lines as self-calibration patterns, four and more sequence images of different viewing points are obtained, a Harris-based sub-pixel angle detection method is used to extract four intersections of self-calibration patterns in each image, and the image coordinates of the two vanishing points are calculated. According to a projection geometry characteristic that a light center is perpendicular to the connection line of the two vanishing points, the constraint equations of camera intrinsic parameters are listed, and the intrinsic parameters such as a image plane main point coordinate (u0, v0) and normalized focal lengths fx and fy are obtained. According to the method, a calibration plate and a calibration block are not needed, the acquisition of camera motion information and the world coordinate information of the self-calibration patterns are not needed, the calibration process is convenient, a shooting requirement is not high, the algorithm is simple and efficient, and large visual field, zoom and remote vision detection applications can be satisfied. The calibration precision is better than the precision of a three-vanishing-point self-calibration method, and the calibration of high precision can be completed by using a low-resolution camera.

Description

technical field [0001] The invention relates to a camera self-calibration method based on two vanishing points. Background technique [0002] Camera calibration is the process of solving the camera parameters by determining the mapping relationship between the 3D coordinates of the space point and the 2D coordinates projected onto the image (see: Li Yunxiang. Research on Camera Calibration and 3D Reconstruction Technology [D]. Qingdao University, 2009). Camera calibration is the process of quantitatively recovering 3D data from 2D images in computer vision. It is a necessary and key link to complete 3D reconstruction of images. It is widely used in 3D modeling, navigation, and video surveillance. Whether in image measurement or machine vision applications, the accuracy of camera parameter calibration results and the stability of algorithms directly affect the accuracy of camera work results. Therefore, camera calibration is the premise of doing a good job in the follow-up w...

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Problems solved by technology

LiuYing et al. proposed a camera calibration method based on coplanar vanishing points (see: LiuY, WuYX, WuMP, "PlanarVanishingPointsBasedCameraCalibration," IEEEComputerSociety, 460-463(2004)), this method requires the production of precisely positioned lattice templates, strict matching Image points and template points, the process is more complicated

Hu Zhaozheng proposed an algorithm that only use

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