Study On The Calibration Of Non-metric Digital Camera

The measuring camera is a camera designed specifically for photogrammetry and can be used directly for aerial photogrammetry.The non-metric camera is ordinary camera used in everyday life,such as SLR cameras,card cameras and so on.The non-measurement digital camera has a lot of features such as light fuselage,low price and easy to carry and so on.In the field of close-range photogrammetry,the non-measurement digital camera is widely used,and has gradually become the main image acquisition equipment in the aerial photogrammetry.The camera's internal orientation elements and distortion parameters are unknown,and the camera don't meet the basic col-linear condition equation,resulting in the image can't directly calculate external elements.In this paper,the research on the calibration problem of non-measurement digital camera is carried out by space resection and the calibration method of Zhang Zhengyou.The calibration results are compared and analyzed from the following aspects:the results of distortion parameters are compared and analyzed;comparative analysis of the results of aberration difference;comparative analysis of the results of two camera calibration;the influence of the number and distribution of the control points on the calibration results of the space resection method;the effect of photo number and attitude on the chessboard method of camera calibration results.Finally,the camera parameters obtained by the two calibration methods are applied to the actual aerial photogrammetry and the accuracy of the image is corrected by using the images corrected by different calibration parameters.In order to improve the accuracy and efficiency of the camera calibration,this paper improves the automatic extraction of the calibration point of the school,and improves the computational efficiency of the space resection method.By experimenting with the proposed calibration method,the results show that the radial distortion is greater than the eccentric distortion.The identification point shold be as much as possible and distributed evenly in the whole image.The number of identification points can be compared at 25 Stable results.While using the calibration method of Zhang zhengyou to calibrate the camera,to shot the Calibration Plate from multiple angles,and the number of photos in 10 is the best.The spatial back resection is better than the calibration method of Zhang zhengyou.The result of calibration results is more stable.The feasibility of the proposed method is verified by analyzing and evaluation of the experimental results.In the automatic identification of the identification point,the efficiency has been greatly improAed.