  Structure from motion is an import theme in computer vision. Although great
progress has been made both in theory and applications, most of the algorithms
only work for static scenes and rigid objects. In recent years, structure and
motion recovery of non-rigid objects and dynamic scenes have received a lot of
attention. In this paper, the state-of-the-art techniques for structure and
motion factorization of non-rigid objects are reviewed and discussed. First, an
introduction of the structure from motion problem is presented, followed by a
general formulation of non-rigid structure from motion. Second, an augmented
affined factorization framework, by using homogeneous representation, is
presented to solve the registration issue in the presence of outlying and
missing data. Third, based on the observation that the reprojection residuals
of outliers are significantly larger than those of inliers, a robust
factorization strategy with outlier rejection is proposed by means of the
reprojection residuals, followed by some comparative experimental evaluations.
Finally, some future research topics in non-rigid structure from motion are
discussed.
