Organizations: School of Communication and Information Engineering, Shanghai University, Shanghai, China · Guangdong Laboratory of Artificial Intelligence and Digital Economy (SZ), Shenzhen, China
Polarization imaging provides informative cues for material analysis, scene understanding, and visual perception. However, acquiring complete polarization observations typically requires specialized hardware and multi-angle measurements, thereby increasing system complexity and limiting practical deployment. In this work, we address the problem of predicting the missing 45∘, 90∘, and 135∘ polarization views from a single 0∘ observation by leveraging a learned scene prior. To this end, we propose MPIG (Multi-angle Polarization Image Generation), a Swin Transformer-based framework that couples cross-angle feature interaction with residual decoding to predict angle-dependent intensity variations while preserving shared scene structure. Specifically, measured Stokes differences and polarization-strength-aware supervision guide the recovery of polarization modulation, orientation, and magnitude, while low-rank factorization further reduces the decoding cost. We also construct HighPol, a large-scale real-world polarization dataset comprising 5,474 groups of high-resolution four-angle polarization images collected from diverse indoor and outdoor scenes. Experimental results demonstrate improved image and polarization accuracy, achieving 29.729 dB PSNR, 0.9505 SSIM, and 21.514∘ AoLP MAngE while requiring 85.86 M parameters and 1.126 T FLOPs. Furthermore, downstream validation on glass and semantic-segmentation tasks suggests that the generated polarization images can preserve task-relevant information, demonstrating the effectiveness of MPIG and the practical utility of predicted polarization observations for downstream vision applications.
Figures & tables
Fig. 1: Motivation and practical utility of MPIG. (a) Conventional polarization acquisition requires either four sequential captures with a rotating polarizer or single-shot acquisition using a costly division-of-focal-plane (DoFP) camera. (b) The target acquisition setting uses a standard camera with a fixed 0∘ polarizer to capture one observation I0 , from which MPIG predicts the missing views I^45 , I^90 , and I^135 . (c) The completed observations support polarization-assisted perception, illustrated by DoLP and glass-segmentation results alongside those obtained from four measured views. Both segmentation masks are predictions of the same frozen model, with blue indicating glass. Acquisition setups and angle tiles are schematic.
Fig. 2: Overview of MPIG. Shared encoding and LiteFeature feed three angle-specific decoders with gated native-resolution skips and rank-40 fusion. ACAIM exchanges cross-angle features before residual prediction. Measured images and Stokes differences supervise image fidelity; normalized-Stokes, direction, and magnitude losses emphasize polarization modulation according to GT polarization strength. Insets show LiteFeature and final-stage decoding.
Fig. 3: Overview of the proposed HighPol dataset. (a) Category distribution of the proposed dataset. (b) Representative samples of six major categories, covering different materials, reflection characteristics, and polarization properties.
Dataset
Size
Resolution
Public
Diversity
Pol.strength
PolaRGB [ 12 ]
6500
1224 × 1024
Yes
Med.
High
DeepSfP [ 39 ]
338
1224 × 1024
Yes
Low
Med.
RGBP-Glass [ 14 ]
4511
612 × 512
Yes
Low
High
Film Removal [ 15 ]
315
2448 × 2048
Yes
Low
Med.
Kondo [ 40 ]
44305
256 × 192
No
Synth.
Low
HighPol (Ours)
5474
1224 × 1024
Yes
High
High
TABLE I: Comparison of existing polarization datasets. Diversity denotes scene-type coverage. DeepSfP size follows the authors’ released-set description.
Fig. 4: Qualitative comparison on a HighPol water scene from the test set. Rows show the 90∘ intensity image, DoLP, and AoLP; GT uses the measured four-angle images. DoLP and AoLP share display ranges of [0,1] and [0,180∘) across methods.
Method
Image fidelity
DoLP
AoLP
Physical diagnostics
Complexity
PSNR ↑
SSIM ↑
PSNR ↑
SSIM ↑
MAbsE ↓
MAngE ↓
EΣ↓
r>1↓
Params.
FLOPs
(dB)
(dB)
( ∘ )
( 10−2 )
(%)
(M)
(T)
Pix2Pix [ 34 ]
27.715
0.9263
21.960
0.5525
0.06055
27.217
2.605
0.0863
34.26
0.498
Swin [ 19 ]
26.994
0.9140
21.717
0.5298
0.06483
28.125
2.745
0.0788
39.21
0.287
DDPM [ 35 ]
24.952
0.8631
18.007
0.3521
0.09277
37.330
2.586
0.2570
63.37
18.940
RGB2Pol-MAE [ 16 ]
28.904
0.9437
23.174
0.6125
0.05129
21.718
0.153
0.0621
329.94
1.208
TABLE II: Comparison on the 750-group test set. Bold indicates the best image and polarization accuracy and the lowest computational cost among learned methods.
Fig. 5: Downstream segmentation under frozen-input substitution. (a) ShareCMP and (b) CSFNet-2 on ZJU-RGB-P; (c) building glazing and (d) a vehicle window on HighPol. Within each panel, the intensity input and model weights are fixed. Annotation denotes the reference segmentation, whereas Measured denotes predictions using measured polarization inputs.
ZJU-RGB-P
HighPol
(a) Frozen-input substitution
(b) Input-specific training
(c) Frozen-input substitution
ShareCMP
CSFNet-2
ShareCMP
Glass model (three seeds)
Input condition
mIoU
Glass IoU
mIoU
Glass IoU
mIoU
Glass IoU
Glass IoU
Dice
BF1
Measured
91.967
87.158
91.405
86.114
91.967
87.158
68.09 ± 1.09
80.13 ± 0.94
22.83 ± 1.30
MPIG
91.536
85.889
90.445
83.811
92.042
87.074
65.56 ± 4.27
78.26 ± 3.32
21.76 ± 1.67
Copy- I0
91.392
84.998
89.162
79.538
91.866
86.343
51.80 ± 18.89
65.88 ± 18.01
14.72 ± 4.35
TABLE III: Downstream segmentation performance (%). HighPol results are mean ± standard deviation across three seeds.
Fig. 6: Visual ablation on a reflective car window. Columns show MPIG without ACAIM, polarization supervision, or output residual prediction, followed by full MPIG and GT. DoLP (top) and AoLP (bottom) use a common 192×192 crop and the display ranges of Fig. 4 .
Variant
Image
DoLP
AoLP
PSNR ↑
SSIM ↑
MAbsE ↓
MAngE ↓
w/o ACAIM
29.576
0.9499
0.05134
22.078
w/o polar. supervision
29.688
0.9502
0.05215
21.983
w/o output residual
29.469
0.9488
0.05175
23.161
Full MPIG
29.729
0.9505
0.05037
21.514
TABLE IV: Ablation of MPIG on the HighPol/PolarVis test set.
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