Abstract
Traditional camera calibration is based on the pinhole model, which is an approximation algorithm using untrue geometrical assumptions and giving a single lumped result for the multiple optical elements in a camera. To provide an alternative method of camera calibration, we extend the traditional 2×2 matrix-based paraxial raytracing method to 6×6 in order to trace paraxial rays by using the first-order Taylor series expansion of Snell’s laws. Then we establish the geometric relationship between images and objects. Compared with the Snell’s Law camera calibration model of our previous work, the paraxial model offers explicit analytical sensitivity analysis for the mathematical manipulation of problematical conditions. Compared with the existing pinhole model, the proposed method, in addition to five intrinsic and six extrinsic parameters, gives the position parameters of each optical element of the camera system.
Similar content being viewed by others
Abbreviations
- (xyz)w :
-
world coordinate frame
- (xyz)0 :
-
camera coordinate frame
- j :
-
number to label optical elements, j=1,2,…,k
- i :
-
number to label boundary surface, i=1,2,…,n (=2k−1)
- (xyz) i :
-
coordinate frame embedded in the ith boundary surface
- r i :
-
ith boundary surface with unit normal n i
- P i :
-
incidence point at r i
- ℓ i :
-
refracted unit directional vector of a light ray at r i
- j A i :
-
pose matrix of frame (xyz) i with respect to frame (xyz) j
- ξ i :
-
the refractive index of medium i
- N i =ξ i−1/ξ i :
-
the relative refractive index across the boundary surface r i
- E ex=[t x t y t z ω x ω y ω z ]T :
-
vector of 6 extrinsic parameters
- q j :
-
thickness of element j (j=1,2,…,k)
- e j :
-
position parameter of element j (j=1,2,…,k)
- E in=[u 0 v 0 1/s u 1/s v Ω]T :
-
vector of 5 intrinsic parameters
- E total=[E ex e 2 e 3 ⋅⋅⋅ e k E in]T :
-
vector of 10+k parameters of a camera
References
P.D. Lin, T.T. Liao, J. Dyn. Syst. Meas. Control-Trans. ASME 126, 102–114 (2004)
D. Murray, A. Basu, Trans. Pattern Anal. Mach. Intell. IEEE 16, 449–459 (1994)
C.J. Taylor, D.J. Kriegman, Trans. Robot. Autom. IEEE 14, 417–426 (1998)
Li. Wenjing, S.T. Marcelo, G. Ulf, Opt. Express 14, 12887–12901 (2006)
B. Baumann, E. Götzinger, M. Pircher, C.K. Hitzenberger, Opt. Express 15, 1054–1063 (2007)
Y.I. Abdel-Aziz, H.M. Karara, in Proc. Symp. Close-Range Photo (Am. Soc. Photogr., Falls Church, 1971), pp. 1–18
H. Hatze, J. Biomech. 21, 533–538 (1988)
R. Lenz, R. Tsai, Trans. Pattern Anal. Mach. Intell. IEEE PAMI 10(5), 713–720 (1988)
J. Weng, P. Cohen, M. Herniou, Trans. Pattern Anal. Mach. Intell. IEEE 14, 965–980 (1992)
L. Ma, Y.Q. Chen, K.L. Morre, in Proceedings of the IEEE International Symposium on Intelligence Control, 2003, pp. 799–804
Z. Zhang, in IEEE International Conference on Computer Vision, 1999, pp. 666–673
F.Y. Wang, IEEE Trans. Syst. Man Cybern. 35, 453–464 (2005)
F.Y. Wang, Trans. Robot. Autom. IEEE 20, 121–124 (2004)
P.D. Lin, C.K. Sung, Opt. Express 15, 3012–3022 (2007)
P.D. Lin, C.K. Sung, OPTIK 117, 329–340 (2006)
R.P. Paul, Robot Manipulators. Mathematics, Programming and Control (MIT Press, Cambridge, 1982)
P.D. Lin, C.K. Sung, J. Dyn. Syst. Meas. Control-Trans. ASME 128, 548–557 (2006)