Method for solving parameters in parabolic catadioptric camera through three unparallel straight lines in checkerboard

Abstract

The invention relates to a method for linearly solving parameters in a parabolic catadioptric camera through three unparallel straight lines in a checkerboard. The method is characterized in that only linear elements are utilized, and a template is composed of the three unparallel straight lines on the checkerboard; parabolic catadioptric images of the straight lines are quadratic curves, the parabolic catadioptric camera is used for taking an image of a target, image points of the target are extracted from the image first, fitting is conducted to obtain the curve equation, and the intersection points of every two curves are solved, six sets of orthogonal fading points on the image plane are then obtained according to the geometric properties of a circle and the cross ratio invariance property, and the parameters in the parabolic catadioptric camera are linearly solved for constraints on images of the absolute quadratic curves through the orthogonal fading points. According to the method, the target can be calibrated in a full-automatic mode, and errors caused by measurement in the calibration process are reduced. Due to the fact that the straight lines are the simpler and more comprehensive elements, calibration accuracy is improved in the calibration process of the camera.

Description

technical field [0001] The invention belongs to the field of computer research and relates to a straight line template for solving internal parameters of a parabolic catadioptric camera. Using three non-parallel straight lines on the checkerboard as calibration templates, using the geometric properties of circles and cross-ratio invariance to obtain six groups of orthogonal blanking points, linearly determine the internal parameters of the parabolic catadioptric camera. Background technique [0002] One of the basic tasks of computer vision is to restore the geometric information of objects in three-dimensional space from the two-dimensional image information obtained by the camera, so as to recognize and reconstruct the geometric shape of objects in three-dimensional space. In this process, the relationship between the three-dimensional geometric position of the spatial object point and its corresponding point in the image must be determined, and this relationship is determ...

AI Technical Summary

Problems solved by technology

The document "Plane-based calibration of central catadioptric cameras", (S.Gasparini, P.Sturm, J.P.Barreto, IEEE 12th International Conference on Computer Vision, pp. 1195-1202, 2009) uses a two-dimensional template with control points , these control points can be corner points, drawn points or any points that are easy to extract from the image, but this method needs to use an iterative method to solve the internal and external parameters

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