🤖 AI Summary
Non-rigid registration remains challenged by susceptibility to local minima and high sensitivity to initialization. To address these issues, this paper proposes a robust method combining signed distance function (SDF) matching with skinning eigenmodes—a low-dimensional, smooth deformation subspace parameterization. By imposing intrinsic geometric constraints via the eigenmode subspace and integrating an adaptive-resolution optimization strategy, the approach effectively mitigates overfitting while enhancing modeling capacity for complex nonlinear deformations. Crucially, it significantly reduces dependence on initial alignment, improving convergence stability without sacrificing accuracy. Extensive experiments on medical image and 3D shape registration tasks demonstrate that the proposed method outperforms conventional NRICP in robustness and generalization—particularly under large deformations, where topology is preserved but geometry differs substantially.
📝 Abstract
Non-rigid registration is a crucial task with applications in medical imaging, industrial robotics, computer vision, and entertainment. Standard approaches accomplish this task using variations on the Non-Rigid Iterative Closest Point (NRICP) algorithms, which are prone to local minima and sensitive to initial conditions. We instead formulate the non-rigid registration problem as a Signed Distance Function (SDF) matching optimization problem, which provides richer shape information compared to traditional ICP methods. To avoid degenerate solutions, we propose to use a smooth Skinning Eigenmode subspace to parameterize the optimization problem. Finally, we propose an adaptive subspace optimization scheme to allow the resolution of localized deformations within the optimization. The result is a non-rigid registration algorithm that is more robust than NRICP, without the parameter sensitivity present in other SDF-matching approaches.