Shape Matching

HSD: Hierarchical Spherical Deformation

[Software]

We present hierarchical spherical deformation for group-wise shape correspondence to address template selection bias and minimize registration distortion. In this work, our aim is to develop a continuous and smooth deformation field to guide accurate cortical surface registration. In conventional spherical registration methods, global rigid alignment and local deformation are performed independently. Motivated by the composition of precession and intrinsic rotation, we simultaneously optimize global rigid rotation and non-rigid local deformation by utilizing spherical harmonics interpolation of local composite rotations in a single framework. To achieve this, we indirectly encode local displacements as functions of spherical locations using local composite rotations. Additionally, we introduce an extra regularization term to the spherical deformation that maximizes its rigidity while reducing registration distortion. To improve surface registration performance, we employ the second-order approximation of the energy function, enabling rapid convergence of the optimization process.

Group-wise Shape Correspondence via Entropy Minimization

Macaque Shape Correspondence

[Software] [Tutorial]

We present hierarchical spherical deformation for group-wise shape correspondence to address template selection bias and to minimize registration distortion. In this work, we aim at a continuous and smooth deformation field to guide accurate cortical surface registration. In conventional spherical registration methods, global rigid alignment and local deformation are independently preformed. Motivated by the composition of precession and intrinsic rotation, we simultaneously optimize global rigid rotation and non-rigid local deformation by utilizing spherical harmonics interpolation of local composite rotations in a single framework. To this end, we indirectly encode local displacements by such local composite rotations as functions of spherical locations. Furthermore, we introduce an additional regularization term to the spherical deformation, which maximizes its rigidity while reducing registration distortion. To improve surface registration performance, we employ the second order approximation of the energy function that enables fast convergence of the optimization.

Applications: Shape Correspondence-based (non-brain) 3D Object Analysis

Macaque Molar Shape Analysis

Hippocampal Shape Analysis in Schizophrenia

Substantia Nigra Shape Analysis