Spline Human Motion Recovery

Simultaneous camera pose, 4D reconstruction of an object and deformation clustering from incomplete 2D point tracks in a video is a challenging problem. To solve it, in this work we introduce a union of piecewise subspaces to encode the 4D shape, where two modalities based on B-splines and Catmull-Rom curves are considered. We demonstrate that formulating the problem in terms of B-spline or Catmull-Rom functions, allows for a better physical interpretation of the resulting priors while C
¹
and C
²
continuities are automatically imposed without needing any additional constraint. An optimization framework is proposed to sort out the problem in a unified, accurate, unsupervised and efficient manner. We extensively validate our claims on a wide range of human motions, including articulated and continuous deformations as well as those cases with noisy and missing measurements where our approach provides competing joint solutions.