Camera calibration is a crucial prerequisite in many applications of computer vision. In this paper, a new geometry-based camera calibration technique is proposed, which resolves two main issues associated with the widely used Zhang’s method: (i) the lack of guidelines to avoid outliers in the computation and (ii) the assumption of fixed camera focal length. The proposed approach is based on the closed-form solution of principal lines with their intersection being the principal point while each principal line can concisely represent relative orientation/position (up to one degree of freedom for both) between a special pair of coordinate systems of image plane and calibration pattern. With such analytically tractable image features, computations associated with the calibration are greatly simplified, while the guidelines in (i) can be established intuitively. Experimental results for synthetic and real data show that the proposed approach does compare favorably with Zhang’s method, in terms of correctness, robustness, and flexibility, and addresses issues (i) and (ii) satisfactorily.

中文翻译：

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基于主线封闭式解决方案的基于几何的相机校准

相机校准是计算机视觉在许多应用中的关键前提。在本文中，提出了一种新的基于几何的相机校准技术，该技术解决了与广泛使用的Zhang方法相关的两个主要问题：（i）缺乏避免异常值计算的准则；（ii）固定相机的假设焦距。所提出的方法基于主线的闭合形式的解决方案，主线的交点为主点，而每条主线可以简洁地表示一对特殊坐标系之间的相对方向/位置（两个方向的自由度最大）。图像平面和校准图案。利用这种易于分析处理的图像特征，与校准相关的计算大大简化了，（i）中的指导原则可以直观地建立。综合和真实数据的实验结果表明，在正确性，鲁棒性和灵活性方面，该方法确实与Zhang的方法相比具有优势，并且令人满意地解决了问题（i）和（ii）。