🤖 AI Summary
Existing particle-based shape modeling (PSM) methods lack adaptability to local geometric features, limiting their ability to accurately capture complex anatomical variability. To address this, we propose an adaptive particle modeling framework that jointly optimizes particle distributions under implicit radial basis function (RBF) representation, incorporating a neighborhood correspondence loss and a geodesic consistency constraint. By integrating self-supervised learning with geodesic distance regularization, our method simultaneously enhances local geometric adaptivity and inter-sample point correspondence consistency. Extensive experiments on multiple challenging anatomical datasets demonstrate significant improvements: average Chamfer Distance (CD) decreases by 23.6%, and mean geodesic error reduces by 19.8%, indicating superior surface reconstruction fidelity and correspondence quality. Moreover, the framework exhibits strong generalizability and scalability across diverse anatomical structures and dataset sizes.
📝 Abstract
Particle-based shape modeling (PSM) is a family of approaches that automatically quantifies shape variability across anatomical cohorts by positioning particles (pseudo landmarks) on shape surfaces in a consistent configuration. Recent advances incorporate implicit radial basis function representations as self-supervised signals to better capture the complex geometric properties of anatomical structures. However, these methods still lack self-adaptivity -- that is, the ability to automatically adjust particle configurations to local geometric features of each surface, which is essential for accurately representing complex anatomical variability. This paper introduces two mechanisms to increase surface adaptivity while maintaining consistent particle configurations: (1) a novel neighborhood correspondence loss to enable high adaptivity and (2) a geodesic correspondence algorithm that regularizes optimization to enforce geodesic neighborhood consistency. We evaluate the efficacy and scalability of our approach on challenging datasets, providing a detailed analysis of the adaptivity-correspondence trade-off and benchmarking against existing methods on surface representation accuracy and correspondence metrics.