1. A method for markerless motion capture, comprises the steps of: acquiring video sequences of a subject by a plurality of cameras positioned in a surrounding relationship with the subject; coupling the acquired video sequences to a data processing unit to be processed therein; in said data processing unit, for each frame of a set of frames of said acquired video sequences, (a) constructing a three-dimensional (3-D) volumetric data (voxel) representation of the subject's image, said 3-D voxel representation forming a kinematic structure including a plurality of articulated chains connected at respective joints and composed of said 3-D voxels, (b) transforming said 3-D voxels of said kinematic structure to the Laplacian Eigenspace, each of said 3-D voxels being mapped to a respective one of a plurality of smooth 1-dimensional (1-D) curves in the Laplacian Eigenspace according to a position of said each 3-D voxel in said 3-D voxel representation, (c) segmenting said 1-D smooth curves by 1-D spline fitting in the Laplacian Eigenspace, (d) registering said segmented 1-D smooth curves to a graphical subject model, (e) computing a skeleton curve of the subject from said segmented 1-D smooth curves, (f) estimating a stature of the subject from said skeleton curves computed from said set of frames of said acquired video sequences, (g) constructing an initial skeleton model having skeleton parameters corresponding to the stature of the subject, (h) computing pose parameters of said initial skeleton model, and (i) constructing an initial subject model based on said initial skeleton model parameters and said pose parameters thereof, and displaying said initial subject model at a display unit.