Monocular reconstruction of human motion by qualitative selection

One of the main difficulties when reconstructing human motion from monocular video is the depth ambiguity. Achieving a reconstruction, given the projection of the joints, can be regarded as a search-problem, where the objective is to find the most likely configuration. One inherent problem in such a formulation is the definition of "most likely". In this work, we pick the configuration that best complies with a set of training-data in a qualitative sense. The reason for doing this is to allow for large individual variation within the class of motions, and avoid an extreme bias towards the training-data. In order to capture the qualitative constraints, we have used a set of 3D motion capture data of walking people. The method is tested on orthographic projections of motion capture data, in order to compare the achieved reconstruction with the original motion.