Image restoration under real-world degradations is critical for downstream tasks such as autonomous driving and object detection. However, existing restoration models are often limited by the scale and distribution of their training data, resulting in poor generalization to real-world scenarios. Recently, large-scale image editing models have shown strong generalization ability in restoration tasks, especially for closed-source models like Nano Banana Pro, which can restore images while preserving consistency. Nevertheless, achieving such performance with those large universal models requires substantial data and computational costs. To address this issue, we construct a large-scale dataset covering nine common real-world degradation types and train a state-of-the-art open-source model to narrow the gap with closed-source alternatives. Furthermore, we introduce RealIR-Bench, which contains 464 real-world degraded images and tailored evaluation metrics focusing on degradation removal and consistency preservation. Extensive experiments demonstrate our model ranks first among open-source methods, achieving state-of-the-art performance.
Figures & tables
Figure 2: Overview of our large-scale Synthetic Degradation Data pipeline. We construct nine representative degradation types, including blur, compression artifacts, moiré patterns, low-light, noise, flare, reflection, haze, and rain. Compared with previous synthetic-only pipelines, our upgraded framework incorporates granular noise modeling, segment-aware perturbations, and web-style degradation processes, significantly narrowing the gap between synthetic and real-world distributions. This comprehensive pipeline enables more robust and generalizable restoration learning.
Figure 3: Comparison with state-of-the-art image editing models across nine real-world degradations, including blur, compression artifacts, moiré patterns, low-light, noise, flare, reflection, haze, and rain. We compare our method with large-scale image editing models, such as Seedream 4.5, Nano Banana Pro, GPT-Image-1.5, Step1X-Edit, FLUX.1-Kontext-dev, Qwen-Image-Edit-2511, and LongCat-Image-Edit.
Method
Open-source
Rain Removal
Deblurring
Low-light Enhancement
Haze Removal
Reflection Removal
LPS ↓
RS ↑
FS ↑
LPS ↓
RS ↑
FS ↑
LPS ↓
RS ↑
FS ↑
LPS ↓
RS ↑
FS ↑
LPS ↓
RS ↑
FS ↑
Image Editing Methods
Nano Banana Pro [ 56 ]
No
0.429
2.063
0.236
0.326
1.068
0.144
0.467
0.720
0.077
0.492
1.920
0.195
0.358
1.368
0.176
GPT–Image–1.5 [ 45 ]
No
0.535
2.120
0.197
0.532
1.667
0.156
0.523
1.048
0.100
0.558
1.840
0.163
0.468
2.320
0.247
Seedream 4.5 [ 55 ]
No
0.438
1.500
0.169
0.254
0.255
0.038
0.423
0.600
0.069
0.418
1.140
0.133
0.291
1.156
0.164
LongCat–Image–Edit [ 57 ]
Yes
0.381
1.302
0.161
0.200
0.000
0.000
0.158
0.120
0.020
0.236
0.000
0.000
0.254
1.060
0.158
Table 1: Quantitative comparison on the Rain Removal, Deblurring, Low-light Enhancement, Haze Removal, and Reflection Removal tasks. We compared state-of-the-art (SOTA) image editing models. For each task, we reported LPS ( ↓ ), RS ( ↑ ), and FS ( ↑ ). The best result is marked in bold , and underline indicates the second-best result. The best and second-best open-source results are highlighted with yellow and blue backgrounds, respectively.
Method
Open-source
Deflare
Moiré Patterns Removal
Denoise
Compression Restoration
Avg Total (9)
LPS ↓
RS ↑
FS ↑
LPS ↓
RS ↑
FS ↑
LPS ↓
RS ↑
FS ↑
LPS ↓
RS ↑
FS ↑
LPS ↓
RS ↑
FS ↑
Image Editing Methods
Nano Banana Pro [ 56 ]
No
0.214
1.222
0.192
0.562
1.560
0.137
0.386
0.712
0.087
0.483
1.122
0.116
0.413
1.306
0.153
GPT–Image–1.5 [ 45 ]
No
0.336
1.415
0.188
0.646
1.633
0.116
0.496
0.993
0.100
0.633
1.167
0.086
0.525
1.578
0.150
Seedream 4.5 [ 54 ]
No
0.225
1.104
0.171
0.548
1.600
0.145
0.387
0.770
0.094
0.529
1.136
0.107
0.390
1.029
0.125
LongCat–Image–Edit [ 57 ]
Yes
0.241
1.717
0.261
0.420
1.200
0.139
0.350
0.471
0.061
0.188
0.083
0.014
0.270
0.661
0.097
Table 2: Quantitative comparison on the Deflare, Demoiré, Denoise, and Compression-restoration tasks. The average results of all 9 tasks are reported in the last column. We compared state-of-the-art (SOTA) image editing models. For each task, we reported LPIPS ( ↓ ), RS ( ↑ ), and FS ( ↑ ). The best result is marked in bold , and underline indicates the second-best result. The best and second-best open-source results are highlighted with yellow and blue backgrounds, respectively.
Method
Blur
Rain
Raindrops
Noise
Low-light
Haze
Compression
Average
PSNR ↑
SSIM ↑
PSNR ↑
SSIM ↑
PSNR ↑
SSIM ↑
PSNR ↑
SSIM ↑
PSNR ↑
SSIM ↑
PSNR ↑
SSIM ↑
PSNR ↑
SSIM ↑
PSNR ↑
SSIM ↑
Nano Banana Pro [ 56 ]
20.16
0.68
21.55
0.65
23.29
0.66
24.78
0.89
15.73
0.73
17.63
0.50
19.48
0.58
20.37
0.67
GPT–Image–1.5 [ 45 ]
13.25
0.41
12.52
0.34
13.89
0.31
14.15
0.68
11.00
0.55
12.39
0.28
13.06
0.39
12.89
0.42
Seedream 4.5 [ 55 ]
17.94
0.61
17.61
0.57
18.01
0.58
15.57
0.78
13.64
0.68
15.65
0.44
14.29
0.54
16.10
0.60
LongCat–Image–Edit [ 57 ]
18.53
0.65
17.09
0.52
18.22
0.48
19.77
0.81
15.24
0.70
10.52
0.36
15.64
0.47
16.43
0.57
Qwen–Image–Edit–2511 [ 65 ]
15.60
0.55
14.68
0.46
15.19
0.42
19.73
0.81
7.13
0.17
7.20
0.34
18.29
0.61
13.98
0.48
Table 3: Quantitative comparison on the FoundIR dataset across various real-world degradations. We report PSNR ( ↑ ) and SSIM ( ↑ ). The best results are highlighted in bold , and the second-best results are underlined .
Figure 4: Model performance with varying training steps and training data on RealIR-Bench. The blue line shows transfer training on synthetic degradation data, where the model gradually acquires basic restoration capability. The blue dashed line indicates performance degradation after prolonged training due to the limited diversity of synthetic data. The purple line represents supervised fine-tuning with real-world degradation data, which rapidly improves performance and generalization. The purple dashed segment indicates the onset of overfitting after around 2.5K steps.
Appendix figures & tables16 assets
Supplementary material from the paper’s appendix.
Appendix
Degradation Type
CLIP Text Prompt
Flare
a photo with lens flare, bright streaks of light
Haze
a hazy photo, foggy atmosphere, low contrast
Rain
a rainy photo with rain streaks or raindrops
Low-light
a dark photo, underexposed, low illumination
Blur
a blurry photo with motion blur or out-of-focus regions
Reflection
a photo with glass or mirror-like reflection artifacts
Appendix
Table 4: Semantic prompts used for CLIP-based degradation filtering.
Degradation
Synthetic
Real
Total
Rain
84,968
43,415
128,383
Blur
1,014,229
13,458
1,027,687
Low-light
5,000
7,005
12,005
Hazy
103,971
8,147
112,118
Reflection
68,227
7,604
75,831
Flare
59,520
7,956
67,476
Appendix
Table 5: Statistics of our dataset across different degradation types. The table reports the number of training image pairs from Synthetic Degradation Data and Real-World Degradation Data. The total column indicates the combined number of samples for each degradation category.
Hyperparameters
Transfer Training Stage
Supervised Fine-Tuning Stage
Learning rate
1×10−5
1×10−5→0
LR scheduler
Constant
Cosine
Weight decay
0.0
0.01
Gradient norm clip
1.0
1.0
Optimizer
AdamW ( β1=0.9,β2=0.95,ϵ=1e−8 )
Warm-up steps
100
100
Appendix
Table 6: Training hyperparameters used in the two training stages.
Method
Flare
Moiré
Refl (Postcard)
Refl (Solid)
Refl (Wildscene)
Average
PSNR ↑
SSIM ↑
PSNR ↑
SSIM ↑
PSNR ↑
SSIM ↑
PSNR ↑
SSIM ↑
PSNR ↑
SSIM ↑
PSNR ↑
SSIM ↑
Nano Banana Pro
25.28
0.889
18.86
0.726
20.11
0.821
24.53
0.880
22.27
0.835
22.21
0.830
GPT–Image–1.5
16.86
0.526
11.84
0.549
13.51
0.465
13.97
0.451
14.59
0.527
14.15
0.504
Seedream 4.5
23.88
0.831
15.30
0.643
21.38
0.807
22.16
0.809
21.45
0.783
20.83
0.775
LongCat–Image–Edit
22.57
0.809
15.79
0.670
20.28
0.706
17.12
0.632
21.28
0.805
19.41
0.724
Qwen–Image–Edit–2511
22.45
0.869
16.07
0.673
21.07
0.839
20.17
0.864
23.77
0.896
20.71
0.828
Appendix
Table 7: Quantitative comparison on extra public benchmarks for real-world image restoration tasks. We report PSNR ( ↑ ) and SSIM ( ↑ ). The evaluation is conducted on multiple datasets including Flare-R from Flare7K++ for deflare, UHDM for moiré pattern removalremoval, and the SIR 2 + reflection removal benchmark with three subsets: PostcardDataset, SolidObjectDataset, and WildScene. Flare-R contains real captured flare images, while UHDM provides ultra-high-definition paired moiré images. The SIR 2 + subsets represent different reflection scenarios with diverse scene contents. The best results are highlighted in bold , and the second-best results are underlined .
Metric
Correlation Coefficient
p -value
Kendall’s τb
0.2493
2.96×10−124
SRCC
0.3010
4.62×10−128
PLCC
0.2919
3.21×10−120
Appendix
Table 8: Consistency evaluation between RS metric and subjective human perception.
Figure 5: Examples from our training dataset containing both synthetic and real-world degradation pairs. The upper rows with gray labels show synthesized degradations generated by our pipeline, while the bottom rows highlighted with orange labels correspond to real-world degraded images paired with clean references.
Figure 6: Additional qualitative results of RealRestorer under real-world degradations. Please zoom in for better visualization of details.
Figure 7: Additional qualitative results of RealRestorer under real-world degradations. Please zoom in for better visualization of details.
Figure 8: Examples from our RealIR-Bench. Each degradation category is evaluated using a fixed bilingual prompt.
Figure 9: System instruction used for degradation evaluation.
Figure 10: More qualitative comparison results on RealIR-Bench. Zoom in to see more details.
Figure 11: More qualitative comparison results on RealIR-Bench. Zoom in to see more details.
Figure 12: More qualitative comparison results on RealIR-Bench. Zoom in to see more details.
Figure 13: More qualitative comparison results on RealIR-Bench. Zoom in to see more details.
Figure 14: Qualitative comparison of different training strategies. Models trained only with synthetic degradation data show limited ability to restore complex real-world degradations. In contrast, models trained solely on real-world degradation data tend to overfit, which may harm structural consistency. Our two-stage training strategy effectively balances restoration capability and content consistency.
Figure 15: User study interface used to evaluate the restoration results. Participants are presented with one degraded input image and five restored results generated by different models and are asked to rate them based on restoration quality and consistency.
Hong Kong JC Lab of Smart City and the Department of Computer Science, City University of Hong Kong · School of Computing and Information Systems, Singapore Management University · Computer Science and Information Engineering, National Taiwan University