Camera Calibration Based on the Common Self-polar Triangle of Sphere Images

• Published in: Computer Vision -- ACCV 2014 pp. 19 - 29
• Main Authors: Huang, Haifei, Zhang, Hui, Cheung, Yiu-ming
• Format: Book Chapter
• Language: English
• Published: Cham Springer International Publishing
• Series: Lecture Notes in Computer Science
• Subjects: Circular Points; Self-polar Triangle; Spherical Image; Support Plan; Vanishing Line
• ISBN: 9783319168074; 331916807X
• ISSN: 0302-9743; 1611-3349
• DOI: 10.1007/978-3-319-16808-1_2

Sphere has been used for camera calibration in recent years. In this paper, a new linear calibration method is proposed by using the common self-polar triangle of sphere images. It is shown that any two of sphere images have a common self-polar triangle. Accordingly, a simple method for locating the vertices of such triangles is presented. An algorithm for recovering the vanishing line of the support plane using these vertices is developed. This allows to find out the imaged circular points, which are used to calibrate the camera. The proposed method starts from an existing theory in projective geometry and recovers five intrinsic parameters without calculating the projected circle center, which is more intuitive and simpler than the previous linear ones. Experiments with simulated data, as well as real images, show that our technique is robust and accurate.