WaveletGaussian: Wavelet-domain Diffusion for Sparse-view 3D Gaussian Object Reconstruction
Hung Nguyen, Runfa Li, An Le, Truong Nguyen
TL;DR
Sparse-view 3D Gaussian Splatting struggles with geometry fidelity and expensive diffusion-based repairs. The proposed WaveletGaussian shifts diffusion to the low-frequency LL subband in the wavelet domain and uses a lightweight HF refinement network, augmented by Online Random Masking to efficiently curate diffusion data, achieving substantial reductions in training time while maintaining rendering quality. The approach demonstrates competitive results on Mip-NeRF 360 and OmniObject3D, with about 40% faster training and 0.3–0.5 dB PSNR gains over baselines, validating the benefits of frequency-separated diffusion and efficient dataset creation. This work enables scalable sparse-view object reconstruction with diffusion-assisted refinement at a fraction of the computational cost of RGB-domain diffusion methods.
Abstract
3D Gaussian Splatting (3DGS) has become a powerful representation for image-based object reconstruction, yet its performance drops sharply in sparse-view settings. Prior works address this limitation by employing diffusion models to repair corrupted renders, subsequently using them as pseudo ground truths for later optimization. While effective, such approaches incur heavy computation from the diffusion fine-tuning and repair steps. We present WaveletGaussian, a framework for more efficient sparse-view 3D Gaussian object reconstruction. Our key idea is to shift diffusion into the wavelet domain: diffusion is applied only to the low-resolution LL subband, while high-frequency subbands are refined with a lightweight network. We further propose an efficient online random masking strategy to curate training pairs for diffusion fine-tuning, replacing the commonly used, but inefficient, leave-one-out strategy. Experiments across two benchmark datasets, Mip-NeRF 360 and OmniObject3D, show WaveletGaussian achieves competitive rendering quality while substantially reducing training time.
