Research And Improvement Of Anti-noise Performance Of Optical Calibration Algorithm

Vision is the main way for human to perceive the outside world.With the development of computer technology,computer vision and stereo vision have also been greatly developed.Camera calibration is the basis of machine vision,so it is of great theoretical significance and practical value to the research of computer vision.In computer vision,there are many problems to be solved urgently,the first problem to be solved is the correspondence between the spatial 3D object points and the 2D image points.Then the image captured by the camera is used to restore the object in the space.Herein,it is assumed that there is a simple linear relationship between the image and the 3D space camera captured by the object: [image]=M[object],and thus the matrix M can be regarded as the geometric model of camera imaging.The parameters in M are camera parameters.Usually,these parameters are obtained by experiments and calculations.The process of solving the parameters is called camera calibration or calibration.The purpose of camera calibration is to determine the correspondence between two dimensional image coordinate system and 3D world coordinate system.Therefore,only after the proper calibration of the camera,the camera can be taken according to the one-to-one correspondence between the two-dimensional coordinates of the image and the three-dimensional coordinates of the camera.Firstly,this paper introduces the background of the camera calibration,as well as the current research status at home and abroad.Secondly,the basic theory of camera calibration is explained in detail.The reference frame of the camera calibration theory,such as the image coordinate system,the camera coordinate system and the world coordinate system,is described in detail.The nature of camera calibration is the constraint condition of the image coordinates from the image coordinates to the world coordinate system.The internal and external parameters of the camera are obtained by constraint conditions.In the process of solving the camera parameters,a mathematical model is often used to approximate the replacement camera model.In order to solve the internal and external parameters of the camera matrix thus the linear imaging model is introduced.At the same time because of the existence of fisheye lens distortion,the nonlinear model of camera imaging is introduced,and another research object of camera calibration is obtained.With the development of camera calibration,a variety of camera calibration methods have been appeared.Then the camera calibration method is introduced in detail.The traditional camera calibration method has a high requirement for calibration environment which require the size and shape of the known calibration.Calibration algorithm is also more complex.The camera self-calibration method is an algorithm that does not depend on the calibration object,and uses the constraint condition between the image coordinate system and the world coordinate system to solve the camera parameters.Zhang's calibration method is a new method to solve the camera parameters proposed by Professor Zhang Zhengyou.This method presents a better solution to solve the radial distortion of the camera lens.Through the different directions along the calibration plate images taken using a mathematical formula calculation of linear relationship between the feature points in the image and the 3D point,so as to obtain the internal and external camera parameters.At the same time,the anti-noise performance of the algorithm also has some research,mainly is the distortion problem of fisheye lens,this paper presents a calibration method based on Zhang's an improved two step calibration method.The initial parameters of the method as the analytical solution out using nonlinear least squares method to further improve the internal and external parameters,improves the robustness of the initial values,and the tangential distortion as to consider factors affecting reconstruction precision.In this paper,based on the original research,the anti-noise performance of Zhang Zhengyou calibration algorithm is analyzed,and the anti-noise performance of the calibration algorithm is analyzed by adding some noise in the original calibration board.At the same time,by improving the original algorithm,the anti-noise mechanism is added.The improved algorithm is analyzed and tested.