Research On Calibration Technology Of Non-Metric Digital Camera

Close-range photogrammetry can solve the corresponding three-dimensional reality by taking two-dimensional images of the target object,and it can be applied to almost all fields of social life.In the close-range photogrammetry process,the image is first acquired and then processed.In recent years,image acquisition with non-measurement cameras,especially ordinary digital cameras,has gradually become a trend.To ensure measurement accuracy,non-measurement cameras must be calibrated before use,and camera calibration has gradually become computer vision and Research hotspots in the field of photogrammetry.In this paper,the method of camera calibration is deeply studied.The construction of 2D and 3D control fields is carried out according to the actual situation and specific requirements.A variety of calibration methods based on 2D control field and 3D control field are used to carry out systematic research and analysis.The details are as follows:(1)Based on the camera calibration theory based on 3D control field,the direct linear transformation method is used as the initial value.The single image space resection method is used to carry out the camera calibration experiment.The parameters of each camera are obtained and the inverse is used.The projection method is internally rated for accuracy.The results show that the camera calibration with high-precision 3D control field can achieve 0.3 pixel accuracy,which can meet the requirements of high-precision 3D reconstruction.(2)The calibration principle and model of the calibration method based on checkerboard,ChArUco calibration plate and color coding plate are introduced.And the experimental platform is built,the accurate camera parameters are obtained through experiments,and the measured data is compared with the estimated data calculated by the three camera calibration solutions to verify the reliability of the algorithm.Experiments show that the three calibration methods have good practicability and high precision,which avoids the requirement of high precision equipment required by traditional methods.The two-dimensional control field is convenient and quick to set up,and the calibration process is highly automated,which is suitable for three-dimensional reconstruction of general scenes.