Large visual field camera calibration method based on four sets of collinear constraint calibration rulers

Abstract

The invention discloses a large visual field camera calibration method based on four sets of collinear constraint calibration rulers and belongs to the field of optical measurement. The calibration method comprises steps of arranging four sets of collinear constraint calibration rulers in a large optical measurement field; solving distortion parameters by using unlimited characteristics of the cross ratio and straight line constrains; linearly solving the initial value of the calibrated parameter via the calibrated control point in the space; and at last by combining the distortion coefficients and the calibrated initial value and using the L-M optimization method, performing overall optimization with the goal of minimizing the re-projection error so as to get the calibrated precise result of the large visual field camera. According to the invention, by flexibly arranging the calibration control point in the large view field measurement space and combining the four sets of collinear constraint calibration rulers, overall optimization is performed on the calibrated results, high precision calibration for the large view field camera is achieved and the calibration method has a wide application prospect.

Description

technical field [0001] The invention belongs to the field of visual measurement and relates to a method for calibrating a camera with a large field of view based on four sets of collinear constraint calibration rulers. Background technique [0002] With the continuous progress of society, more and more measurement problems are faced in industrial production. How to improve the accuracy and efficiency of measurement has become a hot issue in related research fields. Visual measurement has the advantages of non-contact, good real-time performance, high efficiency and the ability to realize on-machine measurement. It has been widely used in the fields of industrial measurement and machinery manufacturing in recent years, and has attracted great attention. Camera calibration is a key part of visual measurement, and the accuracy of the calibration results will directly determine the accuracy of the final measurement results. There are three main calibration methods used for visu...

AI Technical Summary

Problems solved by technology

[0003] In order to solve the problem that the existing calibration method has certain limitations for large field of view calibration, the present invention invented a large field of view camera calibration method based on four sets of collinear constraint calibration rulers

Its purpose is to solve the problem that the high-precision calibration object of the traditional calibration method is difficult to process and the measurement accuracy is difficult to guarantee in the large-field calibration. By flexibly arranging the calibration control points in the large-field measurement space and combining four sets of collinear constraint calibration rulers, Compiled relevant Matlab calculations and image extraction functions, optimized the calibration results as a whole, and realized high-precision calibration of large field of view cameras

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