Consistent Scene Understanding in 3D Gaussian Splatting via Multi-Cue Mask Refinement

Refining fragmented SAM masks into view-consistent object identities for 3D Gaussian Splatting.

* Corresponding author
Figurines
Figurines ground truth
GT
Figurines SAM initial mask
SAM Initial Mask
Figurines refined mask
Refined Mask

Comparison between the ground-truth annotation, the initial SAM mask, and our refined mask on the Figurines scene. In this cluttered roomtop scene with many small objects, the initial SAM mask often produces fragmented or overly fine-grained predictions, whereas our method yields cleaner object-level masks with more consistent identities.

Ramen
Ramen ground truth
GT
Ramen SAM initial mask
SAM Initial Mask
Ramen refined mask
Refined Mask

Comparison between the ground-truth annotation, the initial SAM mask, and our refined mask on the Ramen scene. While the initial SAM mask over-segments fine-grained texture patterns such as those on the room, our method suppresses these spurious fragments and recognizes them as part of a single coherent object.

Blue Sofa
Blue Sofa ground truth
GT
Blue Sofa SAM initial mask
SAM Initial Mask
Blue Sofa refined mask
Refined Mask

Comparison between the ground-truth annotation, the initial SAM mask, and our refined mask on the Blue Sofa scene. While the initial SAM mask produces fragmented predictions such as sunglasses and piggy-like doll, our method consolidates them into a cleaner and more coherent object-level segmentation.

Teatime
Teatime ground truth
GT
Teatime SAM initial mask
SAM Initial Mask
Teatime refined mask
Refined Mask

Comparison between the ground-truth annotation, the initial SAM mask, and our refined mask on the Teatime scene. When looking at the sheep and bear dolls, over-segmented masks are merged into object-level units.

Room
room ground truth
GT
room SAM initial mask
SAM Initial Mask
room refined mask
Refined Mask

Comparison between the ground-truth annotation, the initial SAM mask, and our refined mask on the room scene. While the initial SAM mask tends to produce unclean boundaries and fragmented parts for neighboring objects, our method refines them into clearer object-level segments with improved consistency.

Snacks
Snacks ground truth
GT
Snacks SAM initial mask
SAM Initial Mask
Snacks refined mask
Refined Mask

Comparison between the ground-truth annotation, the initial SAM mask, and our refined mask on the Snacks scene. While the initial SAM mask over-segments fine-grained patterns such as buttons on the calculator or pocky on the snack box, our method successfully merge those fragments and recognizes them as part of a single coherent object.

Covered Desk
Covered Desk ground truth
GT
Covered Desk SAM initial mask
SAM Initial Mask
Covered Desk refined mask
Refined Mask

Comparison between the ground-truth annotation, the initial SAM mask, and our refined mask on the Covered Desk scene. In this cluttered scene with many adjacent objects, the initial SAM mask tends to generate fragmented or inconsistent object parts, whereas our method consolidates them into cleaner object-level masks with improved structural consistency.

01

Overview

2D foundation models like SAM often produce fragmented, view-inconsistent masks, limiting object-level 3D understanding. We refine these masks with semantic, depth, and edge cues, match identities across views, and lift them into a consistent 3D Gaussian feature field. Our method significantly improves cross-view consistency and segmentation quality over existing baselines, while preserving high-fidelity reconstruction.

Multi-Cue Mask Refinement Cross-View Consistency View-Consistent 3D Gaussians
02

Method

Pipeline overview

From multiview images, MCM refines SAM masks with multi-cue evidence, matches identities across views, and lifts them into a view-consistent, object-level 3D Gaussian feature field.

  1. 1

    Multi-Cue Extraction

    Generates synergistic semantic, geometric, and structural priors from each input view.

  2. 2

    Multi-Cue-Guided Mask Merging

    Consolidates fragmented SAM masks with a composite score derived from semantic, depth, and edge cues.

  3. 3

    Cross-View Mask Matching

    Establishes globally consistent object identities across all viewpoints.

  4. 4

    Feature Lifting

    Backprojects refined 2D identities into a view-consistent, object-level 3D Gaussian feature field.

Composite Merge Score

MCM scores neighboring mask pairs by semantic, depth, and edge agreement, merging fragments of the same object while strong boundary evidence keeps distinct objects apart.

\[ S(i, j) = w_{\mathrm{sem}}\cdot \mathrm{cos}(f_i, f_j) + w_{\mathrm{depth}}\cdot \mathrm{exp}{(-{|\bar{d}_i - \bar{d}_j|^2} / 2\sigma_d^2)} - w_{\mathrm{dbound}}\cdot \mathrm{max}(\nabla_D \cap \partial m_{ij}) - w_{\mathrm{edge}}\cdot \mathrm{max}(\nabla_{\mathrm{edge}} \cap \partial m_{ij}) \]

Semantic and depth agreement push \(S(i,j)\) up; boundary evidence pulls it down — masks merge only when appearance and geometry agree, and stay separated across real object edges.

Interactive Demo

Watch It Refine

Figurines ground truth Figurines SAM initial mask Figurines refined mask
GT SAM Initial Mask Refined Mask

Contributions

Multi-Cue Mask Refinement

A framework that reduces SAM's over-segmentation using multiple cues.

Cross-View Matching

Establishes globally consistent object IDs across all viewpoints.

Feature Lifting

Transfers 2D identities to 3D Gaussians, filtering unreliable assignments via majority voting.

Extensive Evaluation

Large gains in object assignment accuracy on LERF, Replica, and real-world scenes.

03

Results

Qualitative Result

Qualitative results

Our refinement stays faithful to the scene and consistent across viewpoints, shown here against three baselines.

* For clearer visualization, this figure enhances edge visibility and overlays object IDs on the masks.

View Consistency

View consistency results

Unlike the GaussianGrouping baseline, which over-segments and drifts across views, our masks stay clean and consistent as the viewpoint changes.

Quantitative Result

Comparison on the LERF and Replica datasets.

Category Model PSNR ↑ SSIM ↑ LPIPS ↓ mIoU ↑ mBIoU ↑ #Mask ↓
Standard 3DGS 28.6 0.88 0.11
3D Segmentation Gau-Group 28.6 0.88 0.12 0.685 0.642 9,627
SAGA 28.2 0.87 0.15 0.712 0.658 178
InstanceGaussian 28.8 0.87 0.15 0.702 0.662 101
Feature Field Feature3DGS 27.5 0.84 0.18 0.538 0.485
GARField 28.1 0.87 0.16 0.710 0.615
CF3 28.3 0.87 0.14 0.524 0.582
Proposed Ours 28.6 0.89 0.13 0.728 0.677 67

Bold = best, underlined = second-best.

0.728mIoU
Best mask accuracy among all baselines
0.677mBIoU
Best boundary-aware accuracy
67masks
vs. 9,627 for Gaussian Grouping
28.6dB PSNR
No loss in photometric quality
04

BibTeX

@inproceedings{park2026consistent,
        title={Consistent Scene Understanding in 3D Gaussian Splatting via Multi-Cue Mask Refinement},
        author={Park, Hyunjoon and Cho, Donghyeon},
        booktitle={International Conference on Pattern Recognition (ICPR)},
        year={2026},
        url={https://hjpark83.github.io/consisGS.github.io/}
      }