Clean-GS: Semantic Mask-Guided Pruning for 3D Gaussian Splatting
Subhankar Mishra
TL;DR
Clean-GS addresses the problem of pervasive floaters in 3D Gaussian Splatting by introducing a semantic-mask-guided pruning pipeline. It combines three stages—whitelist filtering, depth-buffered color validation, and neighbor-based outlier removal—operating with sparse semantic supervision (as few as three masks) to isolate target objects. The approach achieves 60-80% model compression on monument datasets while preserving rendering quality, enabling web deployment and AR/VR applications; processing runs in minutes on commodity multi-core CPUs. The work demonstrates that semantic guidance can outperform global importance-based pruning for object isolation in 3DGS and provides open-source code to facilitate adoption in heritage, visualization, and real-time rendering workflows.
Abstract
3D Gaussian Splatting produces high-quality scene reconstructions but generates hundreds of thousands of spurious Gaussians (floaters) scattered throughout the environment. These artifacts obscure objects of interest and inflate model sizes, hindering deployment in bandwidth-constrained applications. We present Clean-GS, a method for removing background clutter and floaters from 3DGS reconstructions using sparse semantic masks. Our approach combines whitelist-based spatial filtering with color-guided validation and outlier removal to achieve 60-80\% model compression while preserving object quality. Unlike existing 3DGS pruning methods that rely on global importance metrics, Clean-GS uses semantic information from as few as 3 segmentation masks (1\% of views) to identify and remove Gaussians not belonging to the target object. Our multi-stage approach consisting of (1) whitelist filtering via projection to masked regions, (2) depth-buffered color validation, and (3) neighbor-based outlier removal isolates monuments and objects from complex outdoor scenes. Experiments on Tanks and Temples show that Clean-GS reduces file sizes from 125MB to 47MB while maintaining rendering quality, making 3DGS models practical for web deployment and AR/VR applications. Our code is available at https://github.com/smlab-niser/clean-gs
