Nonrigid motion analysis based on dynamic refinement of finite element models

• Published in: IEEE transactions on pattern analysis and machine intelligence Vol. 22; no. 5; pp. 526 - 543
• Main Authors: Tsap, L.V., Goldof, D.B., Sarkar, S.
• Format: Journal Article
• Language: English
• Published: New York IEEE 01.05.2000; The Institute of Electrical and Electronics Engineers, Inc. (IEEE)
• Subjects: Algorithms; Finite element analysis; Finite element method; Finite element methods; Image analysis; Image motion analysis; Information geometry; Iterative algorithms; Iterative methods; Material properties; Mathematical analysis; Mathematical models; Motion analysis; Solid modeling; Studies; Three dimensional; Tracking
• ISSN: 0162-8828; 1939-3539
• DOI: 10.1109/34.857007

We propose new algorithms for accurate nonrigid motion tracking. Given an initial model representing general knowledge of the object, a set of sparse correspondences, and incomplete or missing information about geometry or material properties, we can recover dense motion vectors using finite element models. The method is based on the iterative analysis of the differences between the actual and predicted behaviors. Unknown parameters are recovered using an iterative descent search for the best nonlinear finite element model that approximates nonrigid motion of the given object. During this search process, we not only estimate material properties, but also infer dense point correspondences from our initial set of sparse correspondences. Thus, during tracking, the model is refined which, in turn, improves tracking quality. Experimental results demonstrate the success of the proposed algorithm. Our work demonstrates the possibility of accurate quantitative analysis of nonrigid motion in range image sequences with objects consisting of multiple materials and 3D volumes.