Novel camera calibration method based on two crossed straight lines

Abstract

The invention relates to a novel camera calibration method based on two crossed straight lines. The method comprises the following steps: (1), manufacturing a calibration object; (2), shooting and imaging; (3), detecting the coordinate of a pixel; (4), building an equation for each picture; (5), constructing a linear system of equations according to equations of all pictures shot in the step (2) to obtain the equations in the step (4), and solving the linear system of equations to obtain the a camera parameter matrix; and (6), performing non-linear optimization on the result in the step (5), constructing a target function, and using the minimum target function to obtain the minimum distance between the estimated image position of the camera matrix and the actual image position. According to the invention, the constraints of difficulty in free movement of the calibration object in the shooting process are eliminated, so as to achieve better calibration accuracy; and particularly, a pre-treatment technique provided by the invention in the calibration process is beneficial to improving the accuracy and the stability of the calibration algorithm through maintaining the linear relation of the calibration object to reduce the coordinate error of an image point.

Description

technical field [0001] The present invention relates to the technical field of camera calibration, in particular to the calibration technology based on a calibration object, and specifically refers to a new camera calibration method based on two intersecting straight lines. Background technique [0002] Camera calibration is one of the key technologies in photogrammetry, 3D imaging and image geometry correction. Its main function is to estimate the internal parameters of the camera. The accuracy of the calibration results and the stability of the calibration algorithm directly affect the accuracy of subsequent work. In recent years, international and domestic scholars have proposed many new camera calibration technologies [1-5], which can be roughly classified into two categories: calibration object calibration technology and self-calibration technology. The former needs to make a specific calibration object, which can achieve good calibration accuracy, while the latter dir...

AI Technical Summary

Problems solved by technology

The collinear three-point or non-collinear three-point calibration object is simple and easy to make, but there is a motion constraint between the camera and the calibration object during the calibration process. For example, literature [4] requires a distance between one end point of the calibration object and the camera The relative position of must remain unchanged, which requires precise setting of the scene, thus making the calibration process more complicated

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