Autolabeling 3D tracks using neural networks.

Motion capturing systems based on monochrome video have problems assigning measured 3D marker positions to the anatomically defined positions or labels of the markers applied to the test subject. This task is usually called "labelling" and is paramount to the reconstruction of 3D trajectories from a set of video frames from multiple cameras--the tracking procedure. Labelling means sorting a set of 3D vectors by their spatial positions. Neural networks can be made to "learn" from examples of marker positions in a given marker set, i.e. previously manually tracked video sequences. Trained neural networks are able to calculate a set of sorted approximate marker positions from an unsorted set of exact marker positions. The set of sorted exact positions can be found by pairing up both sets of marker positions via a minimum distance function. The neural network is trained only once and can then be applied to any number of individuals. The algorithm is designed for cyclic motions like for locomotion analysis.

[1]  Raúl Rojas,et al.  Theorie der neuronalen Netze , 1993 .

[2]  David G. Stork,et al.  Pattern Classification , 1973 .

[3]  Philipp Slusallek,et al.  Introduction to real-time ray tracing , 2005, SIGGRAPH Courses.

[4]  S H Holzreiter,et al.  Assessment of gait patterns using neural networks. , 1993, Journal of biomechanics.

[5]  Padraig Cunningham,et al.  The NeuralBAG algorithm: optimizing generalization performance in bagged neural networks , 1999, ESANN.

[6]  Jake K. Aggarwal,et al.  Human Motion Analysis: A Review , 1999, Comput. Vis. Image Underst..

[7]  H. M. Karara,et al.  Direct Linear Transformation from Comparator Coordinates into Object Space Coordinates in Close-Range Photogrammetry , 2015 .

[8]  Pascal Fua,et al.  Skeleton-based motion capture for robust reconstruction of human motion , 2000, Proceedings Computer Animation 2000.

[9]  S. Holzreiter,et al.  Programming language for motion analysis , 1996 .

[10]  Thomas B. Moeslund,et al.  A Survey of Computer Vision-Based Human Motion Capture , 2001, Comput. Vis. Image Underst..

[11]  Tatyana Lopatenok,et al.  The Model-Based Approach of Markers Identification and Visualisation in Motion Capturing Systems , 2002, SimVis.

[12]  Christopher M. Bishop,et al.  Neural networks for pattern recognition , 1995 .

[13]  Devesh K Bhatnagar.  Position trackers for Head Mounted Display systems: A survey , 1993 .

[14]  Jake K. Aggarwal,et al.  Human motion analysis: a review , 1997, Proceedings IEEE Nonrigid and Articulated Motion Workshop.

[15]  E. Mikhail,et al.  Introduction to modern photogrammetry , 2001 .