Algorithm of space plane parameters based on cross ratio invariance
ZHANG Zhengwu 1, 2, CHEN Guoding1, GAO Mantun1, SONG Chunming 1, 2(1. School of Mechatronics, Northwestern Polytechnical Univ., Xi’an 710072, China; 2. School of Mechanical Eng., Shaanxi Univ. of Tech., Hanzhong Shaanxi 723003,China)
With the problems that computing cross radio by image coordinates may cause computational breakdown or deterioration of accuracy, the points and lines on the image plane are represented in terms of N-vectors, and the formula for computing cross radio are established by N-vectors. An application example is enumerated that the space plane parameters are confirmed based on invariance of cross radio. In the algorithm, the 3D orientation of space plane and distance to space plane from viewpoint are computed by using four distinct points on space plane through N-vectors. The example shows that the algorithm has more utility and reliability than traditional algorithms.