SparseStreet
Sparse Gaussian Splatting for Real-Time Street Scene Simulation

ICMR 2026
Qingpo Wuwu1, Xiaobao Wei2, Peng Chen2, Nan Huang3, Zhongyu Zhao1, Hao Wang1, Ming Lu1, Ningning Ma4, Shanghang Zhang1
1Peking University   2Chinese Academy of Sciences   3University of Illinois Urbana-Champaign   4NIO
Peking University
TL;DR: SparseStreet is a plug-and-play compression framework for 3D Gaussian Splatting in street scenes, achieving up to 80% reduction in Gaussian primitives and 2× faster rendering with minimal quality degradation.
SparseStreet Teaser

Gaussian projections before and after pruning. SparseStreet effectively removes redundant primitives in background regions while preserving dense representation for dynamic objects (vehicles, pedestrians), enabling real-time rendering without sacrificing visual fidelity.

Abstract

While 3D Gaussian Splatting has shown promising results in street scene reconstruction, existing methods require massive numbers of Gaussian primitives to capture fine details, leading to prohibitive storage costs and slow rendering speeds. We observe that dynamic objects (e.g., vehicles and pedestrians) demand high-fidelity representations to maintain temporal consistency, while static background regions often contain substantial redundancy. Motivated by this, we propose SparseStreet, a general compression framework specifically designed for street scenes. First, we introduce a node-based learnable pruning strategy that systematically removes low-contributing Gaussian primitives while preserving visually critical regions. Second, after the scene representation stabilizes, we apply background compression, further reducing redundancy in static regions. Our method effectively preserves the geometry and appearance of dynamic objects while significantly reducing the total number of Gaussian primitives. Extensive experiments on the Waymo and nuScenes datasets demonstrate that SparseStreet achieves up to 80% compression ratio with minimal quality degradation, enabling resource-efficient, high-fidelity dynamic scene reconstruction.

Method

SparseStreet Method Overview

SparseStreet Framework. Our two-stage compression pipeline: (1) Node-aware pruning — each Gaussian primitive is enhanced with a learnable masking score, and a node-aware regularization strategy applies different pruning strengths to foreground dynamic nodes (vehicles, pedestrians) versus static background nodes. (2) Background compression — after the scene stabilizes, global importance metrics combining blending weights and projected areas are used to further remove redundant background Gaussians.

Qualitative Results

Ground Comparisons

Qualitative comparisons of Ground Truth (GT), OmniRe, and OmniRe + Ours. The rightmost column shows Gaussian projections of our method. Red boxes highlight that static elements (ground plane, buildings) are effectively represented with fewer Gaussians, while dynamic objects (pedestrians) maintain dense representation for better quality.

Stage 2 Pruning Comparison

Comparison of pruning strategies on dynamic objects across three camera views. Row 1: Ground truth. Row 2: Global pruning — moving vehicles lose parts due to limited temporal presence. Row 3: Our background pruning — preserves dynamic objects while compressing static elements. Row 4: OmniRe baseline.

Quantitative Results

Waymo Open Dataset

Method Full Image (Recon) Human (Recon) Vehicle (Recon) Full Image (NVS) Human (NVS) Vehicle (NVS) # Gauss↓ FPS↑
PSNR↑SSIM↑ PSNR↑SSIM↑ PSNR↑SSIM↑ PSNR↑SSIM↑ PSNR↑SSIM↑ PSNR↑SSIM↑
EmerNeRF 31.930.90222.880.57824.650.723 29.670.88320.320.45422.070.609
3DGS 26.000.91216.880.41416.180.425 25.570.90616.620.38716.000.407
HUGS 28.260.92316.230.40424.310.794 27.650.91415.990.37823.270.748
DeformGS 27.970.92317.230.42919.140.544 26.470.88416.840.39118.210.487 0.64M37.08
PVG 32.680.94124.960.72624.360.763 28.730.88121.950.56521.430.617 1.51M9.13
StreetGS 28.730.93216.540.40126.460.848 27.020.88716.270.36823.990.761 0.87M21.60
OmniRe 34.260.95626.990.82527.790.886 29.860.90023.160.67424.520.786 1.55M46.15
StreetGS + Ours 28.420.92416.510.39226.330.847 27.040.88916.180.36223.720.753 0.29M57.66
OmniRe + Ours 34.050.95226.880.81827.480.878 30.010.90423.150.66724.490.786 0.46M80.22

nuScenes Dataset

Method Full Image (Recon) Human (Recon) Vehicle (Recon) Full Image (NVS) Human (NVS) Vehicle (NVS) # Gauss↓ FPS↑
PSNR↑SSIM↑ PSNR↑SSIM↑ PSNR↑SSIM↑ PSNR↑SSIM↑ PSNR↑SSIM↑ PSNR↑SSIM↑
DeformGS 32.310.92431.760.90028.180.864 25.010.72824.020.57020.960.574 0.43M278.80
StreetGS 32.060.92831.420.90129.680.915 24.290.69823.420.54621.050.557 0.72M117.80
OmniRe 32.140.92932.140.91729.720.916 24.240.69623.380.55121.010.555 0.73M132.56
StreetGS + Ours 31.080.91330.080.86828.560.897 24.060.69823.210.54420.900.558 0.26M461.17
OmniRe + Ours 31.370.91831.160.90028.800.902 24.050.69623.280.54920.960.551 0.38M435.85

M = million Gaussian primitives. Recon = Scene Reconstruction. NVS = Novel View Synthesis.

BibTeX

@inproceedings{wuwu2026sparsestreet,
  title     = {SparseStreet: Sparse Gaussian Splatting for Real-Time Street Scene Simulation},
  author    = {Wuwu, Qingpo and Wei, Xiaobao and Chen, Peng and Huang, Nan and Zhao, Zhongyu and Wang, Hao and Lu, Ming and Ma, Ningning and Zhang, Shanghang},
  booktitle = {Proceedings of the International Conference on Multimedia Retrieval (ICMR)},
  year      = {2026},
}