A Factorization Method for Structure from Planar Motion

We propose a factorization method for structure from planar motion using a stationary perspective camera. Compared with [A factorization based algorithm for multi-image projective structure and motion] for general motion, our work has three major differences: a different measurement matrix specialized for planar motion is formed. The measurement matrix has a rank of at most 3, instead of 4; the measurement matrix needs similar scalings, but estimation of fundamental matrices or epipoles is not needed; we have an Euclidean reconstruction instead of a projective reconstruction. The camera is not required to be calibrated. A simple semi-automatic calibration method using vanishing points and lines is sufficient. Experimental results show that the algorithm is accurate and fairly robust to noise and inaccurate calibration.