PolarVis: A Dataset and Diffusion Framework for RGB-to-Polarization Perception in Adverse Driving Scenes
Authors: Ruilin Huang, Jue Wang, Zhen Tian, Xia Hua, F. Richard Yu
Organizations: School of Communication and Information Engineering, Shanghai University, Shanghai 200444, China · Guangdong Laboratory of Artificial Intelligence and Digital Economy (SZ), Shenzhen 518107, China · Department of Electrical Engineering, Carleton University, Ottawa, Ontario K1S 5B6, Canada
Reflections, glare, transparent structures, and material-dependent appearance variations can introduce ambiguity into RGB-based visual perception in vehicle-relevant environments. Polarization provides complementary reflection- and material-sensitive information, but its acquisition requires dedicated sensing hardware. This paper presents RGB-P Wild, a real-world dataset containing 10,000 paired RGB and four-angle linear-polarization image sets, together with PolarVis, a diffusion-based framework for recovering polarization representations from a single RGB image. PolarVis combines hierarchical RGB feature extraction, diffusion-based feature refinement, four angle-specific decoders, and multi-scale attention recalibration to reconstruct polarization intensity images at 0∘, 45∘, 90∘, and 135∘. On RGB-P Wild, PolarVis achieves a normalized-domain MSE of 0.0465, a PSNR of 27.83 dB, and an SSIM of 0.8597. Compared with the released PolarAnything model under the adopted evaluation protocol, PolarVis obtains an AoLP error of 25.66∘ and a DoLP MAE of 0.0404, compared with 46.03∘ and 0.1084, respectively. Cross-dataset evaluation on vehicle-mounted imagery further examines transfer beyond the training domain. In downstream evaluation, a frozen PCDNet achieves AP50/AP50:95 of 86.3%/59.1% on 990 RGBP-Car test images using PolarVis-generated polarization, compared with 87.0%/59.8% using measured polarization. These results indicate that RGB-derived polarization retains useful polarimetric information for the evaluated perception tasks, while remaining distinct from calibrated physical polarization measurements.
Figures & tables
Fig. 1: Overview of PolarVis. Reflective and transparent surfaces commonly encountered in vehicle-relevant environments can significantly impair conventional RGB-based visual perception. We first construct RGB-P Wild, a large-scale RGB-polarization dataset containing diverse outdoor reflective scenes. Leveraging this dataset, PolarVis employs a diffusion-based RGB-to-polarization generation framework to recover polarization representations, including multi-angle polarization images and their corresponding AoLP and DoLP maps. These recovered polarization cues provide complementary information about material properties, reflections, surface geometry, and transparency, which can facilitate reflection-aware visual perception tasks such as reflection removal, transparent object segmentation, surface normal estimation, and 3D reconstruction.
Fig. 2: Qualitative polarization generation results of PolarVis on RGB-P Wild. Given a single RGB image, PolarVis estimates four linear polarization images at 0∘ , 45∘ , 90∘ , and 135∘ . The generated polarization images are visually compared with the corresponding ground-truth polarization observations, showing that the proposed framework can reconstruct the main reflection- and material-related structures across different polarization angles.
Fig. 3: Physical basis and representative applications of polarization imaging. (a) illustrates light–surface interaction; (b)–(c) compare RGB and polarization observations; and (d)–(g) summarize applications reported in prior work, including transparent-object segmentation with PGSNet [ 1 ] , 3D reconstruction with Polarimetric MVIR [ 2 ] , reflection removal with PolarFree [ 3 ] , and surface-normal estimation with TransSfP [ 4 ] . These examples provide application context and are not experimental results of PolarVis.
Fig. 4: Detailed architecture of PolarVis. (a) Overall RGB-to-polarization generation pipeline, including the Swin-Transformer-based feature encoder, optimized diffusion module, and four angle-specific polarization decoders. (b) Illustration of the forward diffusion and reverse denoising processes. (c) Decoder data flow for polarization image reconstruction. (d) Upsampling module in the decoder. (e) Multi-Scale Feature Fusion and Attention Feature Recalibration (FFA) module used to enhance reconstructed polarization features.
Fig. 5: Sample overview of RGB-P Wild. 121 RGB images arranged in an 11×11 grid are selected from 10,000 images in total. The subset covers diverse illumination conditions (daytime/nighttime), object materials (glass, plastic, metal, liquid, etc.), and scene types (indoor/outdoor), reflecting the dataset’s variability in environmental context, material property, and lighting condition.
Fig. 6: Acquisition characteristics of RGB-P Wild: (a) color-polarization sampling and (b) natural-illumination distribution.
Dataset
Size
Resolution
Collection
Public
Level
Environment
RGB-P Glass [ 1 ]
4511
612×512
real-world
✓
Scene
Indoor
SPW [ 18 ]
522
1224×1024
real-world
✓
Scene
Outdoor
DeepSfP [ 37 ]
300
256×256
real-world
✓
Object
Outdoor
Spectro-Polarimetric Dataset [ 17 ]
2022/311
1900×2100 / 512×612
real-world
✓
Scene
Outdoor
Kondo [ 53 ]
44305
256×192
synthetic
×
Object
Outdoor
PolarAnything [ 11 ]
1148
1224×1024
real-world
✓
Scene
Outdoor
TABLE I: Comparison of representative polarization datasets. RGB-P Wild provides large-scale real-world paired RGB-polarization samples at the scene level, covering diverse materials and illumination conditions that are useful for RGB-to-polarization generation and vehicle-relevant reflective-scene perception studies.
GT AoLP ( ∘ )
PolarVis AoLP ( ∘ )
GT DoLP
PolarVis DoLP
117.5878
106.1014
0.1361
0.0929
110.9761
101.2570
0.1387
0.1026
114.4993
106.8212
0.0836
0.0773
148.3800
110.9311
0.1824
0.1146
TABLE II: Image-level comparison of GM ground-truth and PolarVis-predicted polarization attributes. AoLP is summarized by the axial circular mean over the common mask defined by ground-truth DoLP greater than 0.05, and DoLP is averaged over all pixels. These descriptive statistics do not replace pixel-wise error metrics.
Fig. 7: Qualitative transfer to the General Motors Polarimetric Imaging for Perception dataset [ 21 ] . PolarVis predicts four-angle images from RGB, from which AoLP and DoLP are derived. Reference four-angle images are reconstructed using eq. 19 , not directly measured; reference AoLP and DoLP are provided by the dataset.
Fig. 8: Supplementary in-domain qualitative comparison on RGB-P Wild. Complementing the vehicle-scene cross-dataset evaluation in Fig. 7 , PolarVis-generated polarization images are compared with direct ground-truth polarization observations from RGB-P Wild. The generated results preserve the main structural appearance and polarization-related intensity patterns across diverse reflective materials and illumination conditions, while some fine local differences remain in highly reflective or low-texture regions.
Method
Mean Squared Error (MSE) (normalized) ↓
Mean Squared Error (MSE) ↓
Peak Signal-to-Noise Ratio (PSNR) ↑
Structural Similarity Index (SSIM) ↑
Traditional diffusion model
1.5879
5273.0545
11.51
0.3686
Rombach’s decoder [ 14 ]
0.0499
165.4929
27.65
0.8434
StarGAN v2’s decoder [ 69 ]
0.0608
202.0217
26.28
0.8018
Ours
0.0465
155.0706
27.83
0.8597
TABLE III: Quantitative comparison of different diffusion and decoder configurations on RGB-P Wild. The proposed configuration achieves the lowest MSE and the highest PSNR/SSIM among the compared settings.
Fig. 9: Qualitative comparison with PolarAnything [ 11 ] on RGB-P Wild. Each scene shows the RGB input and reference, PolarAnything, and PolarVis AoLP/DoLP maps. Reference maps are derived from measured four-angle images. Grayscale and color-coded views are shown for each source; each pair displays the same underlying attribute. Quantitative results are reported in Table IV .
(a) AoLP/DoLP evaluation
Method
AoLP error ( ∘ ) ↓
DoLP MAE ↓
DoLP RMSE ↓
PolarAnything
46.03
0.1084
0.1528
PolarVis
25.66
0.0404
0.0614
(b) Controlled reconstruction with reference S0
Method
Four-angle MAE ↓
PSNR (dB) ↑
SSIM ↑
PolarAnything
0.03469
25.19
0.8385
TABLE IV: Polarimetric comparison on the 2,500-image RGB-P Wild evaluation split: (a) AoLP/DoLP errors; (b) four-angle reconstruction with a common reference S0 . Part (b) is a controlled analysis, not end-to-end inference.
Steps
Latency (ms) ↓
FPS ↑
Peak memory (MB) ↓
1
88.74
11.27
2682.76
5
95.19
10.51
2683.17
10
103.82
9.63
2682.76
TABLE V: PolarVis inference efficiency at 512×512 resolution on an NVIDIA RTX 4090. The model contains 157.35 million parameters. Latency excludes file I/O, polarization conversion, and downstream inference.
Method
Mean Squared Error (MSE) (normalized) ↓
Mean Squared Error (MSE) ↓
Peak Signal-to-Noise Ratio (PSNR) ↑
Structural Similarity Index (SSIM) ↑
Only channel attention mechanism
0.0567
187.8577
26.79
0.8131
Only spatial attention mechanism
0.1769
588.6359
21.30
0.5939
Only 3×3 convolution layer (remove 1×1 and 5×5 convolutions)
1.6987
5644.3328
11.38
0.3743
Full
0.0465
155.0706
27.83
0.8597
TABLE VI: Ablation study of the Multi-Scale Feature Fusion and Attention Feature Recalibration (FFA) module on RGB-P Wild. The comparison is conducted in terms of normalized Mean Squared Error (MSE), Mean Squared Error (MSE), Peak Signal-to-Noise Ratio (PSNR), and Structural Similarity Index (SSIM). The results show the contribution of multi-scale feature fusion and attention-based recalibration to polarization image reconstruction.
Fig. 10: Transparent and reflective object segmentation results using real and PolarVis-generated polarization cues. The figure visualizes RGB images, real DoLP/AoLP maps, PolarVis-generated DoLP/AoLP maps, and segmentation masks. The results indicate that generated polarization cues can provide useful boundary and reflection-related information for glass-like scene perception.
PGSNet
IoU ↑
Fβw↑
MAE ↓
BER ↓
RGB-P Glass
81.08
0.842
0.091
9.63
Generated by PolarVis
74.11
0.776
0.140
13.79
TABLE VII: Comparison of polarization-assisted segmentation performance via PGSNet. Two input configurations are compared: (1) original RGB-P Glass inputs with real polarization information; and (2) RGB inputs paired with PolarVis-synthesized polarization information. The experiment evaluates whether generated polarization cues can support transparent and reflective object segmentation. Note: ↑ indicates higher values are better; ↓ indicates lower values are better.
Fig. 11: Vehicle detections produced by frozen PCDNet [ 22 ] on four RGBP-Car examples. The top and bottom rows use measured and PolarVis-generated AoLP/DoLP, respectively. Each column uses the same RGB image and detector weights. Aggregate results are reported in Table VIII .
Polarization input
P (%) ↑
R (%) ↑
AP50 (%) ↑
AP50:95 (%) ↑
Measured
87.6
82.3
87.0
59.8
PolarVis-generated
87.6
81.3
86.3
59.1
TABLE VIII: Vehicle detection using frozen PCDNet on 990 RGBP-Car test images. Both rows use identical detector weights and evaluation settings. Measured-polarization results are reproduced locally. All metrics are percentages.
Department of Computer Science, Saint Louis University, St. Louis, MO, USA · MOVEJ Analytics, Fairborn, OH, USA · U.S. Naval Research Laboratory, Washington, DC, USA
Zhejiang University, Hangzhou, China · School of Automation, Central South University, Changsha, China · College of Computer Science and Technology, Zhejiang University of Technology, Hangzhou, China +2
School of Communication and Information Engineering, Shanghai University, Shanghai, China · Guangdong Laboratory of Artificial Intelligence and Digital Economy (SZ), Shenzhen, China