Paper Overview
Field: Computer Vision Authors: Ziyao Shang, Pouya Sadeghi, Letian Jiang, Alexander Wong, Sirisha Rambhatla Published: 2026-09-25 arXiv: 2609.31573
Summary
Biomedical image segmentation is central to medical image analysis, but practical deployment often faces limited annotations, memory constraints, and cross-site distribution shifts. Implicit Neural Representations (INRs) have recently emerged as a lightweight alternative for semantic segmentation, achieving competitive performance with substantially fewer parameters than conventional architectures. However, the mechanisms, scaling behavior, and domain generalization abilities of INR-based segmentation remain insufficiently understood.
Key Findings
- The authors study these questions in the context of cross-domain brain MRI segmentation, analyzing INR-based segmentation in low-parameter regimes and comparing it with conventional pipelines in both in-domain and out-of-domain settings.
- Surprisingly, INR models do not improve monotonically with larger parameter budgets: their advantage is most pronounced in low-parameter, limited-augmentation settings, while U-Net-based models benefit more from larger capacity and standard augmentation.
- INRs encode semantic information across hidden features: complementary segmentation-relevant structures are distributed over multiple INR layers.
- Based on this insight, the authors propose HierINRSeg, a hierarchical INR segmentation architecture that aggregates multi-layer representations for improved robustness and generalization.
- Extensive experiments show HierINRSeg consistently outperforms the recent strong baseline MetaSeg, with an average in-domain test Dice improvement of 5.6 percentage points and an out-of-domain improvement of 8.2 percentage points.
Original Abstract
Biomedical image segmentation is central to medical image analysis, but practical deployment often faces limited annotations, memory constraints, and cross-site distribution shifts. Implicit Neural Representations (INRs) have recently emerged as a lightweight alternative for semantic segmentation, achieving competitive performance with substantially fewer parameters than conventional architectures. However, the mechanisms, scaling behavior, and domain generalization abilities of INR-based segmentation remain insufficiently understood. In this work, we study these questions in the context of cross-domain brain MRI segmentation. We analyze INR-based segmentation across low-parameter regimes, comparing it with conventional pipelines in both in-domain and out-of-domain settings. Surprisingly, ...
--- *Automatically collected on 2026-09-29*