Organizations: Electronic Information School, Wuhan University, Wuhan, 430072, China · Suzhou Institute, Wuhan University, Suzhou, 215123, China · School of Robotics, Wuhan University, Wuhan, 430072, China
Existing image fusion methods struggle to balance visual quality and semantic attributes due to the inherent conflict between their optimization objectives. To address this challenge, we propose an attack-defense semantic reinforcement framework for multi-modal image fusion, termed AD-SRF. By decoupling the optimization of these two aspects and then losslessly reintegrating them, this framework injects rich semantic attributes into the fused image without compromising its visual quality. First, we develop a transformer-based restorative visual fusion network as a strong visual baseline. Equipped with the cross-modal retrieval module and the information restoration-fusion collaborative loss, it produces highly visible fused images even under degraded conditions. Second, we introduce an attack-defense game mechanism to strengthen the semantic attributes of the fused images. The attacker learns perturbation patterns that impair downstream segmentation, whereas the defender restores missing semantics from the original inputs and reintegrates them into the fused image through an imperceptible semantic map. Through iterative adversarial interaction, this mechanism drives the defender to continually strengthen the fused image's semantic attributes, boosting downstream segmentation performance without compromising visual quality. Extensive experiments demonstrate that AD-SRF achieves a win-win performance in both visual quality and semantic attributes. The code is publicly available at https://github.com/HaoZhang1018/AD-SRF.
Figures & tables
Fig. 1: Comparative analysis of existing coupled and our proposed decoupled paradigms. Our AD-SRF achieves both high-fidelity visual representations and accurate semantic decision performance under adverse conditions, whereas the SOTA competitor suffers from weakened visualization and missed detections.
Fig. 2: The overall pipeline of our proposed attack-defense semantic reinforcement framework for multi-modal image fusion (AD-SRF). It starts from a strong visual baseline and leverages an attack-defense game to learn imperceptible semantic maps, improving the visual quality of fused images and their semantic affinity for the downstream segmentation task under degraded conditions.
Fig. 3: An Optimization Perspective on ADG: Principles and Visualizations. We demonstrate the principles of ADG from an optimization perspective, complemented by confidence map visualizations that verify the stability and precision of the reinforced features.
Fig. 4: Qualitative comparison of our method and existing image fusion methods under standard setting.
Methods
MFNet
FMB
PSNR ↑
AG ↑
EN ↑
SSIM ↑
QAB/F↑
NAB/F↓
PSNR ↑
AG ↑
EN ↑
SSIM ↑
QAB/F↑
NAB/F↓
SeAFusion [ 9 ]
63.8112
3.6301
6.4217
0.3979
0.4700
0.0225
59.9176
4.2748
6.7538
0.2829
0.2685
0.0107
MRFS [ 16 ]
62.7057
3.2083
7.0467
0.3595
0.4061
0.0207
60.5819
3.6545
6.7777
0.2593
0.2219
0.0122
EMMA [ 29 ]
63.3372
4.0151
6.6118
0.3881
0.4896
0.0219
60.8850
4.6881
6.7729
0.2968
0.3333
0.0110
KDFuse [ 30 ]
63.7641
3.7307
6.4990
0.3840
0.5067
0.0224
60.2450
4.2054
6.6484
0.2676
0.2662
0.0114
Text-IF [ 31 ]
63.2369
4.0099
6.7773
0.4119
0.5598
0.0205
60.8934
4.4739
6.7402
0.2784
0.3085
0.0097
TABLE I: Quantitative vision results on MFNet and FMB datasets under standard setting.
Fig. 5: Qualitative comparison of our method and competitive methods on semantic segmentation under standard setting.
Methods
Car
Pers.
Bike
Curve
C.S.
Guar.
Cone
Bump
mIoU
SeAFusion [ 9 ]
89.7
74.1
64.5
46.4
37.6
4.7
51.5
51.4
57.6
MRFS [ 16 ]
89.4
75.4
65.1
49.0
37.2
5.4
53.1
58.8
59.1
EMMA [ 29 ]
89.2
72.6
63.4
47.6
29.4
6.3
54.6
59.8
57.9
KDFuse [ 30 ]
90.1
73.9
65.8
48.3
27.2
4.7
59.0
56.2
58.2
Text-IF [ 31 ]
90.1
72.9
65.2
47.2
34.7
5.4
55.6
54.1
58.2
A 2 RNet [ 21 ]
90.1
72.9
65.2
47.2
34.7
5.4
55.6
54.1
58.2
TABLE II: Quantitative segmentation results on MFNet dataset under standard setting (mIoU is averaged over all 9 categories).
Methods
BG.
Road
Side.
Build.
Lamp
Sign
Veg.
Sky
Pers.
Car
Truck
Bus
Motor.
Bike
Pole
mIoU
SeAFusion [ 9 ]
15.75
86.71
52.08
83.53
49.29
75.23
86.30
94.61
69.38
83.56
54.59
74.40
39.79
-
50.93
61.08
MRFS [ 16 ]
17.04
86.94
46.28
85.39
50.07
75.75
86.98
95.11
71.31
76.16
34.44
28.63
49.03
-
53.64
57.12
EMMA [ 29 ]
16.77
87.67
49.80
83.30
47.99
75.61
86.62
94.04
67.94
83.35
57.49
75.08
45.09
-
50.99
61.45
KDFuse [ 30 ]
17.16
88.19
49.17
83.79
45.09
76.70
86.87
94.32
69.67
83.41
56.71
74.24
47.73
-
54.33
61.82
Text-IF [ 31 ]
16.37
87.65
49.99
85.17
46.48
75.37
85.75
94.08
68.94
83.48
57.97
74.90
48.07
-
54.25
61.90
A 2 RNet [ 21 ]
18.42
88.02
49.68
83.29
40.77
77.06
86.55
93.85
68.38
82.37
43.37
73.05
41.03
-
52.59
59.89
TABLE III: Quantitative segmentation results on FMB dataset under standard setting (mIoU is averaged over all 15 categories). Test set lacks bike class.
Methods
FMB
PSNR ↑
AG ↑
EN ↑
SSIM ↑
QAB/F↑
NAB/F↓
SeAFusion † [ 9 ]
57.1016
5.3778
6.5741
0.2784
0.3469
0.0073
MRFS † [ 16 ]
60.4472
3.5689
6.8023
0.2535
0.2128
0.0122
KDFuse † [ 30 ]
59.9691
4.9620
6.6208
0.2917
0.3674
0.0090
Text-IF † [ 31 ]
60.5321
4.7523
7.1092
0.3117
0.3147
0.0080
A 2 RNet † [ 21 ]
62.0232
5.6666
6.9115
0.2325
0.3742
0.0096
TABLE IV: Quantitative results on FMB dataset under retraining enhancement setting.
Methods
BG.
Road
Side.
Build.
Lamp
Sign
Veg.
Sky
Pers.
Car
Truck
Bus
Motor.
Bike
Pole
mIoU
SeAFusion † [ 9 ]
17.50
88.83
52.80
84.07
49.22
76.46
87.07
94.36
69.12
82.20
55.23
59.43
42.49
-
55.03
60.92
MRFS † [ 16 ]
16.99
86.84
46.15
85.35
48.83
75.85
86.88
95.11
71.18
76.18
34.75
28.52
48.50
-
53.35
56.96
KDFuse † [ 30 ]
17.87
88.05
52.17
82.51
46.84
76.50
86.47
94.14
68.76
83.24
58.57
61.98
44.94
-
53.01
61.00
Text-IF † [ 31 ]
17.09
88.03
49.92
83.85
48.86
75.65
86.97
94.08
70.66
83.19
57.40
68.84
42.57
-
54.80
61.46
A 2 RNet † [ 21 ]
15.85
85.49
48.44
82.53
40.66
74.88
85.86
94.47
66.11
81.83
59.47
65.29
47.12
-
52.68
60.04
TDFusion † [ 32 ]
17.02
88.22
51.38
85.21
47.38
75.05
87.07
94.37
69.70
83.98
58.87
76.50
44.72
-
53.19
62.18
TABLE V: Quantitative segmentation results on FMB dataset under retraining enhancement setting (mIoU is averaged over all 15 categories). Test set lacks bike class.
Fig. 6: Qualitative comparison of our method and existing image fusion methods under retraining enhancement setting.
Fig. 7: Qualitative comparison of our method and existing image fusion methods under retraining enhancement setting.
Methods
MFNet
FMB
PSNR ↑
SSIM ↑
PSNR ↑
SSIM ↑
IfH+ζA
48.72
0.9949
51.34
0.9948
IfH+ζD
47.02
0.9910
50.96
0.9942
IfH+ζD+ζA
45.64
0.9883
49.31
0.9913
TABLE VI: Visual fidelity validation of ADG paradigm.
Fig. 8: Qualitative validation of ADG paradigm: visual fidelity and semantic interaction.
Datasets
Ψ(IfH)
Ψ(IfH+ζA)
Ψ(IfH+ζD)
Ψ(IfH+ζD+ζA)
MFNet
59.61
57.77
61.65
61.01
FMB
62.27
60.39
63.87
63.72
TABLE VII: Semantic interaction validation of ADG paradigm.
Fig. 9: Qualitative applications to the task of polarization image fusion.
Fig. 10: Qualitative applications to the task of near-infrared and visible image fusion.
Methods
Polarization
PSNR ↑
AG ↑
EN ↑
SSIM ↑
QAB/F↑
NAB/F↓
SeAFusion [ 9 ]
62.0774
2.2667
6.5333
0.2711
0.2265
0.1661
MRFS [ 16 ]
61.5999
1.4195
6.7700
0.2224
0.1628
0.1412
EMMA [ 29 ]
61.7656
2.1649
6.7912
0.2624
0.2210
0.1501
KDFuse [ 30 ]
62.2455
2.1002
6.5313
0.2589
0.2197
0.1738
Text-IF [ 31 ]
62.0376
2.4223
6.7537
0.3094
0.2423
0.1662
TABLE VIII: Quantitative results on Polarization image fusion.
Methods
NIR-VIS
PSNR ↑
AG ↑
EN ↑
SSIM ↑
QAB/F↑
NAB/F↓
SeAFusion [ 9 ]
65.1848
5.5793
7.2054
0.5399
0.3544
0.0460
MRFS [ 16 ]
64.2899
3.9187
7.1277
0.4324
0.2219
0.0570
EMMA [ 29 ]
65.1122
5.6443
7.2679
0.5326
0.3594
0.0479
KDFuse [ 30 ]
64.8639
4.9950
7.1430
0.4913
0.2981
0.0554
Text-IF [ 31 ]
64.7539
5.3033
7.2012
0.5240
0.3321
0.0495
TABLE IX: Quantitative results on NIR-VIS image fusion.
Fig. 11: Qualitative results of ablations on visual components.
Fig. 12: Qualitative results of ablations on semantic components.
Ablations
PSNR ↑
AG ↑
EN ↑
SSIM ↑
QAB/F↑
NAB/F↓
Model I
62.0865
5.4873
7.0925
0.3293
0.4028
0.0093
Model II
61.1906
5.4129
6.9576
0.3257
0.3766
0.0083
Model III
59.3522
5.9259
7.0201
0.3359
0.4408
0.0087
Full Model
61.2501
5.8770
7.1544
0.3368
0.4219
0.0081
TABLE X: Quantitative results of ablations on visual components.
Ablations
Road
Side.
Build.
Sign
Veg.
Sky
Pers.
Car
mIoU
Model I
89.09
53.50
84.66
76.60
87.81
94.53
70.50
85.58
62.92
Model II
87.85
48.26
85.01
77.39
87.10
94.54
69.91
83.28
62.27
Model III
90.51
55.61
84.79
76.40
87.05
94.86
69.99
85.86
63.00
Model IV
89.57
56.80
85.11
77.59
87.44
94.79
71.51
85.82
63.33
Full Model
90.14
57.36
85.44
77.75
87.81
94.92
71.73
86.15
63.87
TABLE XI: Quantitative results of ablations on semantic components.
Methods
Road
Side.
Build.
Sign
Veg.
Sky
Pers.
Car
mIoU
KDFuse
88.19
49.17
83.79
76.70
86.87
94.32
69.67
83.41
61.82
KDFuse ∗
90.43
54.50
83.98
76.84
87.49
94.12
70.06
84.74
63.06
Text-IF
87.65
49.99
85.17
75.37
85.75
94.08
68.94
83.48
61.90
Text-IF ∗
89.21
56.22
83.70
76.64
87.17
93.47
70.76
84.89
63.10
ControlFusion
88.52
49.54
84.34
76.57
86.27
94.16
71.00
84.20
61.67
ControlFusion ∗
89.11
52.07
84.21
77.00
87.14
93.96
71.47
85.73
63.22
TABLE XII: Quantitative evaluation of ADG’s generalization performance across various fusion methods.
Fig. 13: Consistent semantic gain with ADG across multiple fusion methods.
Existing multi-modal image fusion (MMIF) methods generally face an optimization gap between the visual and semantic domains, limiting the enhancement of perception capabilities. To overcome this long-standing barrier, this work proposes W2F, a new visual-semantic mutual reinforcing paradigm for MMIF. First, we reinforce the foundation for visual-semantic collaboration by amplifying feature complementarity through two targeted designs. Specifically, the segmentation-guided fusion loss introduces object-aware structural guidance into visual fusion, while the embedded information restoration prior strengthens the ability of visual fusion to provide reliable perceptual evidence for the semantic branch under degraded conditions. Then, we introduce a strong multi-modal information interaction mechanism composed of interactive gated mixed attention (IGM-Att) and progressive coupling attention (PC-Att). These modules ensure comprehensive scene representation from both local and global perspectives, providing informational support for visual-semantic collaboration. Finally, we construct a collaborative mechanism to couple visual fusion and semantic fusion. It employs a feature search module to extract complementary key features from both tasks, enriching the representational potential of visual and semantic information. Meanwhile, a gradient correction strategy ensures collaboration from the optimization perspective, enhancing performance for both visual and semantic fusion through consistency learning. Extensive experiments demonstrate that W2F surpasses state-of-the-art methods in both visual appeal and decision accuracy. The code is publicly available at https://github.com/HaoZhang1018/W2F.
Hao Zhang, Xuhui Zuo, Jiayi Ma
Electronic Information School, Wuhan University, Wuhan 430072, China
Multimodal image fusion (MMIF) aims to integrate complementary sensor data into a single representation that preserves intrinsic scene reality while eliminating environmental interferences. Most existing approaches rely on blind feature aggregation, which excels at signal accumulation but fails to distinguish essential content from physical degradations. We propose SGPDFuse, which bridges this gap by mapping inputs into a physics-disentangled structural representation via a Semantic-Physical Parametric Bridge (SPPB) built on pretrained vision foundation models, utilizing the Intrinsic-Variation principle to decouple invariant scene attributes from transient environmental factors. To guide this decomposition, we introduce a Semantic Alignment mechanism: we explicitly anchor the fused representation to salient semantic features in the same foundation model feature space via cosine similarity to preserve critical targets, while enforcing physical texture fidelity through Gram-matrix regularization to strictly eliminate unnatural artifacts. Extensive experiments demonstrate that SGPDFuse achieves state-of-the-art performance across infrared-visible, multi-focus, and multi-exposure benchmarks using a single architecture.
Haozhen Wei, Chengjun Jiang, Yutong Guo +4
Dalian University of Technology Dalian, Liaoning, China · City University of Hong Kong Hong Kong, China · Zhejiang University Hangzhou, Zhejiang, China
Multi-modality image fusion (MMIF) enhances scene representation by exploiting complementary cues from different modalities. Adverse weather, however, causes significant image degradation, disrupting feature representation and requiring simultaneous feature restoration and cross-modal complementarity. Existing methods often struggle with effective representation learning under such conditions, limiting their practical performance. To address these challenges, we propose a mask-guided MMIF method that integrates feature restoration and interaction. We first introduce "Pseudo Ground Truth" to simplify training, promoting faster and more effective feature learning. Then, we design a mask generation mechanism based on the mapping relationship between the fused result and the source images, quantifying the relative contribution of each modality during the fusion process. By incorporating the proposed mask-guided cross-modal cross-attention mechanism, the network is encouraged to selectively attend to informative features during modality interaction, mitigating the risk of overfitting to the static distribution of the "Pseudo Ground Truth". Additionally, we propose a mask-guided learning strategy and a task-coupled degradation-aware learning strategy to balance feature restoration and interaction. Extensive experiments on synthetic and real-world datasets demonstrate that our method surpasses state-of-the-art approaches in visual quality, quantitative metrics, and downstream tasks. The source code is available at https://github.com/ixilai/AMG-Fuse.
Xilai Li, Xiaosong Li, Haishu Tan +3
Foshan University, Foshan, China · China University of Mining and Technology, Beijing, China · Kunming University of Science and Technology, Kunming, China