Scalable Feature Matching via State Space Modeling and Sparse Correlation

摘要

Efficient and robust feature matching is crucial for latency-sensitive and resource-constrained applications. However, many current semi-dense feature matching methods scale quadratically with spatial resolution, either due to transformer-based long-range context modeling or from redundant full correlation computations. To overcome these limitations, we present SLiM (Salient Lightweight Matching), a novel scalable feature matching method that delivers reliable matches with low memory footprint and latency, especially at high resolutions. Our approach introduces three key innovations: (1) a hybrid Conv-Mamba backbone for efficient cross-scale and cross-view feature extraction with linear complexity, (2) a training-free norm-based feature filtering mechanism, enabling sparse correlation that significantly reduces computation overhead during inference, and (3) a lightweight recurrent coordinate refinement that surpasses expectation-based regression in subpixel accuracy. Experimental results show that SLiM consistently achieves a strong accuracy-efficiency trade-off across indoor and outdoor benchmarks, with clear advantages in memory usage, inference speed, and high-resolution scalability. These results demonstrate the practical efficiency and strong scalability of SLiM. Project page: https://github.com/Band-127/SLiM