Issue No. 08 - August (2006 vol. 28)
Xiaolei Huang , IEEE
Nikos Paragios , IEEE
Dimitris N. Metaxas , IEEE
We present a novel, variational and statistical approach for shape registration. Shapes of interest are implicitly embedded in a higher-dimensional space of distance transforms. In this implicit embedding space, registration is formulated in a hierarchical manner: the Mutual Information criterion supports various transformation models and is optimized to perform global registration; then, a B-spline-based Incremental Free Form Deformations (IFFD) model is used to minimize a Sum-of-Squared-Differences (SSD) measure and further recover a dense local nonrigid registration field. The key advantage of such framework is twofold: 1) it naturally deals with shapes of arbitrary dimension (2D, 3D, or higher) and arbitrary topology (multiple parts, closed/open) and 2) it preserves shape topology during local deformation and produces local registration fields that are smooth, continuous, and establish one-to-one correspondences. Its invariance to initial conditions is evaluated through empirical validation, and various hard 2D/3D geometric shape registration examples are used to show its robustness to noise, severe occlusion, and missing parts. We demonstrate the power of the proposed framework using two applications: one for statistical modeling of anatomical structures, another for 3D face scan registration and expression tracking. We also compare the performance of our algorithm with that of several other well-known shape registration algorithms.
Shape registration, mutual information, free form deformations, correspondences, implicit shape representation, distance transforms, partial differential equations.
D. N. Metaxas, N. Paragios and X. Huang, "Shape Registration in Implicit Spaces Using Information Theory and Free Form Deformations," in IEEE Transactions on Pattern Analysis & Machine Intelligence, vol. 28, no. , pp. 1303-1318, 2006.