Research On Intrinsic Parameters Calibration Of CE-3Panoramic Camera

With the successful landing of CE-3satellite, marking the development ofChina’s aerospace industry is booming, still, the following research on the datapassed by the satellite is carrying out. In order to make the follow-up work of3Dreconstruction going on well, camera calibration is more than the indispensable part.As an important part of computer vision, the purpose of camera calibration is toestablish a relationship between the two-dimensional image coordinates and thethree-dimensional object coordinates. The traditional camera calibration method isbased on objects that have the shape and size already known, and, because of theproduction of a stereo object is not only simple, but also cost low, and thethree-dimensional coordinates of the control points of are easy to get, mostimportantly, can be directly used to solve the collinearity equation, stereo objects arecommonly used in camera calibration. Since the traditional camera calibrationmethod can only be used on three-dimensional calibration targets, this paperdiscusses how to use two-dimensional calibration targets and image coordinates tocalibrate a camera. The process also involves the choosing of the two-dimensionalcalibration target, because there are a variety of calibration target type, how tochoose the right camera calibration grid point to improve both the stability andaccuracy of calibration result is one key problem of this research. In this paper, atarget contained circular grid points is used as the calibration reference object, andthe main works were as follows:(1) Derived by the collinearity equation, we can get to know Tsai’s method,two-dimensional DLT algorithm, Zhang algorithm, Heikkil’s algorithm and severalother main camera calibration algorithms. By analyzing the current tools andsoftware implemented based on these algorithms, and doing experiments with theCE-3panoramic camera using these tools, we can summarize the pros and consthrough the analysis of experimental results. Thereby the best camera calibrationalgorithm suited the CE-3panoramic camera can be find.(2) Circular grid points are used as control points, owing that the projection ofcircular control points is asymmetrical projection, the center of the point projectedon the image may not be center of the projection image, hence it is necessary tocorrect the lens distortion introduced by asymmetric projection. Furthermore, the number of circular control points on the calibration target is huge, using traditionalcalibration methods is time consuming and takes up a large memory space, a newcircle extraction method is bringing forward. Finally, in order to achieve fullautomation in camera calibration process, an automatic sorting algorithm will begiven, reducing manual intervention in the calibration process.