Organizations: School of Computer Science and Technology, Zhejiang Sci-Tech University · School of Biomedical Engineering, Tsinghua University · CardioCloud Medical Technology (Beijing) Co., Ltd. · Lishui University · State Key Laboratory of Blockchain and Data Security, Zhejiang University · College of Artificial Intelligence, Jiaxing University
COLMAP-free 3D Gaussian Splatting (3DGS) bypasses computationally expensive structure-from-motion (SfM) pipelines, yet progressive camera pose tracking remains fundamentally vulnerable to error compounding---early pairwise tracking inaccuracies both corrupt subsequent frame initializations and remain permanently frozen in the scene representation. Rather than relying on heavyweight external neural priors or treating progressive tracking through isolated heuristic fixes, we propose a unified reliability-regulated trajectory optimization framework for progressive COLMAP-free 3DGS. At its core, our framework establishes an intrinsic, self-supervised bidirectional cycle-consistency mechanism that systematically regulates progressive camera trajectory estimation across two complementary temporal horizons: (1) Forward Motion Propagation, where the online reliability signal adaptively gates first-order kinematic warm-starts of rigid motion into upcoming pairwise registrations, supplying informed directional search priors while safely intercepting untrusted transitions; and (2) Retrospective Trajectory Correction, where the same reliability signal dynamically weights relative-pose consistency constraints within a sliding window of neighboring camera poses. By governing both prospective state initialization and retrospective trajectory consolidation through a unified reliability regulator, our self-contained framework resolves progressive drift without external priors or offline preprocessing. Extensive evaluations on Tanks and Temples and CO3D-V2 benchmarks show that our method substantially improves camera trajectory accuracy and novel-view rendering quality, outperforming existing unposed baselines. Code is available at https://github.com/Zijian1026/RRTO-CF3DGS.
Figures & tables
Figure 1: Qualitative comparison on novel-view synthesis and camera trajectory estimation. Our reliability-regulated trajectory optimization prevents local error compounding along the sequence and eliminates trajectory drift relative to CF-3DGS.
Figure 2: Overview of the proposed reliability-regulated trajectory optimization framework. Given an unposed image sequence, our framework establishes an intrinsic bidirectional cycle-consistency signal to systematically regulate progressive camera estimation across two complementary temporal phases: (a) Forward Motion Propagation , where tracking confidence adaptively gates first-order kinematic extrapolation on SE(3) to supply an informed warm-start while intercepting corrupted priors; and (b) Retrospective Trajectory Correction , where camera poses within a sliding window are jointly optimized under fixed Gaussian geometry, constrained by multi-view photometric alignment and confidence-weighted relative pose consistency. Shared cycle reliability ensures that noisy transitions neither corrupt future registrations nor distort local window trajectory refinement.
Figure 3: Qualitative novel-view synthesis results on the Tanks and Temples benchmark. We compare our method against unposed baselines. While existing methods exhibit severe blurring, missing structures, and geometric distortion due to noisy or drifted pose estimates, our approach produces photorealistic renderings with fine-grained textures and sharp edges. Inset red and green boxes highlight key detailed regions.
Scene
Nope-NeRF [ 17 ]
CF-3DGS [ 18 ]
HT-3DGS [ 22 ]
PCR-GS [ 23 ]
Ours
PSNR
SSIM
LPIPS
PSNR
SSIM
LPIPS
PSNR
SSIM
LPIPS
PSNR
SSIM
LPIPS
PSNR
SSIM
LPIPS
Ballroom
24.43
0.71
0.28
24.92
0.83
0.12
25.62
0.85
0.11
25.16
0.83
0.12
28.16
0.91
0.07
Barn
23.00
0.61
0.40
19.26
0.57
0.38
20.33
0.56
0.35
19.00
0.53
0.46
22.01
0.67
0.27
Church
23.01
0.65
0.37
26.83
0.87
0.14
27.80
0.89
0.12
27.31
0.89
0.13
27.53
0.89
0.12
Family
24.59
0.71
0.35
25.03
0.85
0.16
27.80
0.89
0.12
27.15
0.90
0.12
28.31
0.91
0.11
Francis
23.01
0.66
0.43
23.90
0.74
0.27
24.31
0.72
0.26
24.77
0.73
0.26
25.96
0.77
0.25
Table 1: Quantitative novel view synthesis results on the Tanks and Temples benchmark with stride 5. Held-out test views are evaluated using PSNR ↑ , SSIM ↑ , and LPIPS ↓ . Best results are bolded.
Figure 4: Qualitative comparison on challenging 360-degree object-centric sequences from CO3D-V2. On the displayed sequences with wide baselines and continuous rotational trajectories, competing methods exhibit trajectory deviations and rendering artifacts such as floaters and blurriness. Our reliability-regulated framework produces more accurate trajectory estimates and higher-fidelity Gaussian reconstructions.
Method
PSNR ↑
SSIM ↑
LPIPS ↓
CF-3DGS [ 18 ]
26.11
0.782
0.270
HT-3DGS [ 22 ]
26.59
0.800
0.260
PCR-GS [ 23 ]
26.16
0.785
0.272
Ours
27.71
0.819
0.239
Table 2: Average novel view synthesis results on the CO3D-V2 dataset. Test views are evaluated using PSNR ↑ , SSIM ↑ , and LPIPS ↓ . Best results are bolded.
Scene
Nope-NeRF [ 17 ]
CF-3DGS [ 18 ]
HT-3DGS [ 22 ]
PCR-GS [ 23 ]
Ours
RPEt
RPEr
ATE
RPEt
RPEr
ATE
RPEt
RPEr
ATE
RPEt
RPEr
ATE
RPEt
RPEr
ATE
Ballroom
0.127
0.247
0.002
0.279
0.048
0.006
0.279
0.047
0.006
0.295
0.059
0.006
0.122
0.026
0.002
Barn
1.343
0.403
0.033
2.409
0.585
0.065
2.252
0.574
0.057
3.379
1.074
0.118
0.576
0.314
0.011
Church
0.490
0.127
0.044
0.081
0.095
0.004
0.081
0.095
0.004
0.070
0.092
0.005
0.053
0.087
0.003
Family
0.119
0.052
0.003
0.775
0.294
0.011
0.203
0.118
0.004
0.483
0.187
0.006
0.455
0.181
0.006
Francis
2.941
1.515
0.079
0.814
0.916
0.021
0.733
0.878
0.016
0.714
0.816
0.015
0.416
0.747
0.015
Table 3: Quantitative camera pose estimation results on the Tanks and Temples benchmark with stride 5. Trajectories are evaluated using RPEt↓ ( ×102 ), RPEr↓ ( ∘ ), and ATE ↓ . Best results are bolded.
Method
RPEt↓
RPEr↓
ATE ↓
CF-3DGS [ 18 ]
0.579
0.548
0.023
HT-3DGS [ 22 ]
0.545
0.511
0.022
PCR-GS [ 23 ]
0.658
0.842
0.032
Ours
0.352
0.382
0.014
Table 4: Average camera pose estimation results on the CO3D-V2 dataset. Trajectories are evaluated using RPEt↓ ( ×102 ), RPEr↓ ( ∘ ), and ATE ↓ . Best results are bolded.
Figure 5: Reliability verification of bidirectional cycle-consistency confidence. We visualize the temporal trajectory error against the estimated cycle-consistency confidence ci across representative sequences from Tanks and Temples ( A : Family , B : Horse ) and CO3D-V2 ( C : Apple , D : Book ). For each sequence, the upper subplot shows the frame-wise bidirectional confidence ci , while the lower subplot displays the corresponding translational error and rotational discrepancy.
Variant
Controls
Loss Weight
Rendering quality
Pose accuracy
MP
Gate
WJ
PSNR ↑
SSIM ↑
LPIPS ↓
RPEt↓
RPEr↓
ATE↓
CF-3DGS (sequential)
×
–
×
–
21.93
0.709
0.250
1.327
0.695
0.024
WJ, photometric only
×
–
✓
–
22.56
0.724
0.247
1.047
0.623
0.022
WJ + Uniform loss weight
×
–
✓
Uniform
22.74
0.726
0.242
0.998
0.618
0.021
WJ + F–B loss weight
×
–
✓
F–B
22.97
0.729
0.237
0.920
0.610
0.019
Ungated MP
✓
×
×
–
23.58
0.752
0.210
0.714
0.476
0.016
Table 5: Ablation study and reliability calibration on Tanks and Temples. We evaluate the impact of motion-guided initialization (MP), confidence gating (Gate), window joint refinement (WJ), and forward–backward (F–B) consistency weighting. RPEt is reported in ×102 and RPEr in degrees.
Department of Electrical and Computer Engineering, Sungkyunkwan University · Department of Artificial Intelligence, Sungkyunkwan University · Department of Artificial Intelligence, Yonsei University