Cross-ratio-invariance-based linear-array camera calibration method containing eight-diagram coding information

Abstract

The invention, which relates to the technical field of camera calibration, provides a cross-ratio-invariance-based linear-array camera calibration method containing eight-diagram coding information. According to the method, the eight-diagram theory is applied to the design of a linear-array camera calibration plate, so that a pattern of the calibration plate contains the coding information; on thebasis of cross-ratio invariance of projection, intersection points of the pattern on the calibration plate and the view plane of the camera are obtained; calculation is carried out by using the intersection points and corresponding pixel values to obtain internal and external parameters of the linear-array camera and the obtained internal and external parameters of the linear-array camera are used as initial values; and a final calibration result is obtained by using a nonlinear optimization method under an actual imaging model. According to method provided by the invention, the position of the view field line is distinguished clearly without moving the calibration plate; the calibration plate is made simply and the cost is low; and calibration of the linear-array camera is carried out simply and quickly.

Description

technical field [0001] The invention relates to the technical field of camera calibration, in particular to a calibration method for a line array camera containing gossip coding information based on cross-ratio invariance. Background technique [0002] Line scan cameras have the advantages of simple structure, low cost, high resolution, and fast response. Under the premise of the same measurement accuracy, the number of single-row photosensitive units of the line scan camera is more, and a larger measurement range can be obtained, and its transmission of photoelectric conversion signals has high real-time performance, fast scanning speed, and high frequency response, which is easy to meet the requirements of real-time measurement. Require. Therefore, line scan cameras are increasingly being used in real-time 3D coordinate measurement and 3D scene reconstruction of high-speed moving objects in space. [0003] Camera calibration is a necessary step to implement camera applic...

AI Technical Summary

Problems solved by technology

Horaud et al. proposed a method of using a set of known coplanar straight lines for line array camera calibration, using the cross-ratio invariant property to solve the problem of the correspondence between spatial calibration points and image points. This method uses a linear model and the algorithm is simple , but the target needs to be moved precisely, and the accuracy of the movement affects the calibration accuracy

Luna et al. improved Horaud's method to make a three-dimensional target to avoid moving the planar target, but this method puts forward high requirements on the production accuracy of the three-dimensional target, and the number of calibrated feature points on the target surface is small after the target is produced. , which affects the accuracy and stability of the calibration results to a certain extent

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