Direct estimation of range flow on deformable shape from a video rate range camera

A method of estimating range flow (space displacement vector field) on nonrigid as well as rigid objects from a sequence of range images is described. This method can directly estimate the deformable motion parameters by solving a system of linear equations that are obtained from substituting a linear transformation of nonrigid objects expressed by the Jacobian matrix into motion constraints based on an extension of the conventional scheme used in intensity image sequences. The range flow is directly computed by substituting these estimated motion parameters into the linear transformation. The algorithm is supported by experimental estimations of range flow on a sheet of paper, a piece of cloth, human skin, and a rubber balloon being inflated, using real range image sequences acquired by a video rate range camera