Abstract

Finding the relationship between two coordinate systems by using pairs of measurements of the coordinates of a number of points in both systems is a classic photogrammetric task. The solution has applications in stereophotogrammetry and in robotics. We present here a closed-form solution to the least-squares problem for three or more points. Currently, various empirical, graphical, and numerical iterative methods are in use. Derivation of a closed-form solution can be simplified by using unit quaternions to represent rotation, as was shown in an earlier paper [ J. Opt. Soc. Am. A 4, 629 ( 1987)]. Since orthonormal matrices are used more widely to represent rotation, we now present a solution in which 3 × 3 matrices are used. Our method requires the computation of the square root of a symmetric matrix. We compare the new result with that obtained by an alternative method in which orthonormality is not directly enforced. In this other method a best-fit linear transformation is found, and then the nearest orthonormal matrix is chosen for the rotation. We note that the best translational offset is the difference between the centroid of the coordinates in one system and the rotated and scaled centroid of the coordinates in the other system. The best scale is equal to the ratio of the root-mean-square deviations of the coordinates in the two systems from their respective centroids. These exact results are to be preferred to approximate methods based on measurements of a few selected points.

© 1988 Optical Society of America

Closed-form solution of absolute orientation using unit quaternions

Berthold K. P. Horn
J. Opt. Soc. Am. A 4(4) 629-642 (1987)

Relative orientation revisited

Berthold K. P. Horn
J. Opt. Soc. Am. A 8(10) 1630-1638 (1991)

Orthonormal polynomials in wavefront analysis: analytical solution

Virendra N. Mahajan and Guang-ming Dai
J. Opt. Soc. Am. A 24(9) 2994-3016 (2007)

Orthonormal vector general polynomials derived from the Cartesian gradient of the orthonormal Zernike-based polynomials

Cosmas Mafusire and Tjaart P. J. Krüger
J. Opt. Soc. Am. A 35(6) 840-849 (2018)

Definition of a parametric form of nonsingular Mueller matrices

Vincent Devlaminck and Patrick Terrier
J. Opt. Soc. Am. A 25(11) 2636-2643 (2008)