SubSplat: High-Resolution Pixel-aligned 3DGS via Sub-pixel Gaussian Reparameterization

Pixel-aligned Gaussian splatting enables efficient and gen-eralizable novel-view synthesis. However, high-resolution rendering facesa critical trade-off where increasing input resolution improves detail atthe expense of quadratically rising network computational cost. Con-versely, maintaining low-resolution inputs stabilizes this cost but resultsin insufficient Gaussian density and artifacts. To address this, we proposeSubSplat, which introduces Sub-pixel Gaussian Reparameterizer(SPGR)to subdivide primary Gaussians into fine-grained primitives, restoringstructural density directly from low-resolution features. We further en-hance the reparameterization quality through feature aggregation, whicheffectively captures high-frequency details across multiple views. Experi-ments on RealEstate10K and ACID demonstrate that SubSplat achieveshigh-fidelity rendering with superior efficiency. Our results validate thatthe proposed framework successfully resolves the trade-off between repa-rameterization fidelity and network computational cost inherent in pixel-aligned Gaussian Splatting.