Beyond Independence: Learning Correlated Views for Variational Incomplete Multi-View Clustering
Organizations: School of Computer Science & Technology, Beijing Jiaotong University · Key Laboratory of Big Data & Artificial Intelligence in Transportation, Ministry of Education, China · Department of Data Science, BI Norwegian Business School, Oslo, Norway · Department of Physics and Technology, UiT The Arctic University of Norway · Norwegian Computing Center
Abstract
Incomplete multi-view clustering (IMVC) aims to uncover shared cluster structures from data with partially observed views. Although recent imputation-free methods based on variational inference demonstrate robustness to missing views, they commonly rely on a conditional independence assumption across views in the posterior aggregation stage, which fails to capture the inherently structured and potentially correlated nature of multi-view data. In this paper, we propose a variational framework that explicitly goes beyond this assumption by introducing a learnable cross-view correlation structure. Specifically, we explicitly model and learn correlations between views by utilizing the covariance structure of posterior estimation errors during aggregation. To facilitate robust and efficient learning, the correlation matrix is parameterized through a normalized Cholesky decomposition, ensuring positive definiteness and enabling the entire model to be trained jointly through a unified variational objective. Extensive experiments on multiple IMVC benchmarks demonstrate that our method consistently outperforms state-of-the-art approaches across diverse missing-view settings while introducing only a negligible number of learnable parameters. These results highlight the effectiveness of adaptive correlation modeling in variational IMVC, demonstrating the need to go beyond the independence assumption in IMVC. The code is available at https://github.com/zmxu196/ACOVA.
Figures & tables
| Missing Rate | 10% | 30% | 50% | 70% | |||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Metrics | ACC | NMI | ARI | PUR | ACC | NMI | ARI | PUR | ACC | NMI | ARI | PUR | ACC | NMI | ARI | PUR | |
| Scene15 | BSV | 0.3595 | 0.3577 | 0.1784 | 0.4002 | 0.3305 | 0.3206 | 0.1253 | 0.3630 | 0.2944 | 0.2905 | 0.0796 | 0.3321 | 0.2593 | 0.2568 | 0.0472 | 0.2903 |
| Concat | 0.3703 | 0.3820 | 0.2037 | 0.4263 | 0.3360 | 0.3318 | 0.1540 | 0.3825 | 0.2943 | 0.2995 | 0.1201 | 0.3436 | 0.2596 | 0.2665 | 0.0982 | 0.3053 | |
| DCP | 0.4071 | 0.4414 | 0.2488 | 0.4342 | 0.3958 | 0.4264 | 0.2350 | 0.4265 | 0.3879 | 0.4095 | 0.2359 | 0.4166 | 0.3784 | 0.3849 | 0.2113 | 0.4026 | |
| CPSPAN | 0.3574 | 0.3457 | 0.1911 | 0.4103 | 0.3161 | 0.2783 | 0.1541 | 0.3439 | 0.2553 | 0.2070 | 0.1063 | 0.2786 | 0.2025 | 0.1423 | 0.0621 | 0.2198 | |
| DSIMVC | 0.2795 | 0.2976 | 0.1430 | 0.3218 | 0.2734 | 0.2896 | 0.1383 | 0.3131 | 0.2697 | 0.2828 | 0.1335 | 0.3133 | 0.2654 | 0.2741 | 0.1290 | 0.3062 | |
| Variant | 10% | 30% | 50% | 70% | |||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| ACC | NMI | ARI | PUR | ACC | NMI | ARI | PUR | ACC | NMI | ARI | PUR | ACC | NMI | ARI | PUR | ||
| Handwritten | Learn ( w/ corr.) | 0.9363 | 0.8692 | 0.8645 | 0.9363 | 0.9376 | 0.8709 | 0.8669 | 0.9376 | 0.9146 | 0.8489 | 0.8325 | 0.9146 | 0.8999 | 0.8351 | 0.8176 | 0.9021 |
| w/o corr. | 0.9169 | 0.8604 | 0.8547 | 0.9201 | 0.8954 | 0.8470 | 0.8210 | 0.9020 | 0.8980 | 0.8373 | 0.8175 | 0.9054 | 0.7808 | 0.7905 | 0.7197 | 0.8099 | |
| fixed | 0.9339 | 0.8676 | 0.8595 | 0.9339 | 0.9249 | 0.8534 | 0.8418 | 0.9249 | 0.8860 | 0.8288 | 0.8031 | 0.8898 | 0.8881 | 0.8231 | 0.7986 | 0.8918 | |
| fixed | 0.8874 | 0.8513 | 0.8231 | 0.8945 | 0.9217 | 0.8509 | 0.8355 | 0.9217 | 0.8929 | 0.8335 | 0.8093 | 0.8972 | 0.8859 | 0.8219 | 0.7962 | 0.8903 | |
| fixed | 0.9088 | 0.8590 | 0.8391 | 0.9118 | 0.9301 | 0.8612 | 0.8510 | 0.9301 | 0.8710 | 0.8291 | 0.7957 | 0.8821 | 0.8867 | 0.8239 | 0.7962 | 0.8908 | |
Appendix figures & tables15 assets
Supplementary material from the paper’s appendix.
Appendix
| Dataset | #Views | #View Dimensions | #Instances | #Categories |
|---|---|---|---|---|
| Handwritten ( LeCun et al., 1989 ) | 6 | 76, 216, 64, 47, 240, 6 | 2,000 | 10 |
| Caltech5V ( Fei-Fei et al., 2004 ) | 5 | 40, 254, 1984, 512, 928 | 1,400 | 7 |
| Scene15 ( Fei-Fei & Perona, 2005 ) | 3 | 20, 59, 40 | 4,485 | 15 |
| Fashion ( Xiao et al., 2017 ) | 3 | 784, 784, 784 | 10,000 | 10 |
| NoisyMNIST ( Wang et al., 2015 ) | 2 | 784, 784 | 70,000 | 10 |
| CUB Image-Captions ( Zhang et al., 2019 ) | 2 | 1024, 300 | 600 | 10 |
| Method | Venue | #View | Description |
|---|---|---|---|
| BSV ( Zhao et al., 2016 ) | IJCAI | Multiple | Imputes missing views using the view-wise average values and performs clustering using the best-performing single view. |
| CONCAT ( Zhao et al., 2016 ) | IJCAI | Multiple | Similar to BSV that imputes missing views using the view-wise average values, but concatenates features across all views after imputation and then performs K -Means clustering. |
| DSIMVC ( Tang & Liu, 2022 ) | ICML | Multiple | A bi-level optimization-based safe incomplete multi-view clustering framework that dynamically imputes missing views from semantic neighbors and automatically selects reliable imputed samples. |
| DCP ( Lin et al., 2023 ) | PAMI | Two | An information-theoretical framework that unifies cross-view consistency learning and missing-view recovery via dual contrastive learning and dual prediction. |
| CPSPAN ( Jin et al., 2023 ) | CVPR | Multiple | Jointly performs cross-view partial sample alignment and prototype-level alignment to address the challenges of prototype shift under missing-view settings. |
| DVIMC ( Xu et al., 2024 ) | AAAI | Multiple | Employ PoE-based VAEs to construct a shared latent space and mitigate information imbalance via a coherence loss. |
| Hyperparameters | Handwritten | Caltech5V | Scene15 | Fashion | NoisyMNIST | CUB |
| Pretraining Epochs | 200 | 200 | 200 | 200 | 200 | 200 |
| Training Epochs | 300 | 300 | 300 | 300 | 300 | 300 |
| Batch Size | 256 | 256 | 256 | 256 | 512 | 256 |
| Optimizer | Adam | Adam | Adam | Adam | Adam | Adam |
| Scheduler | ExpLR | ExpLR | ExpLR | ExpLR | ExpLR | ExpLR |
| Network Learning Rate |
| Variant | 10% | 30% | |||||||
|---|---|---|---|---|---|---|---|---|---|
| ACC | NMI | ARI | PUR | ACC | NMI | ARI | PUR | ||
| Handwritten | Learn ( w/ corr.) | 0.9363 ± 0.0067 | 0.8692 ± 0.0113 | 0.8645 ± 0.0133 | 0.9363 ± 0.0067 | 0.9376 ± 0.0073 | 0.8709 ± 0.0125 | 0.8669 ± 0.0144 | 0.9376 ± 0.0073 |
| w/o corr. | 0.9169 ± 0.0545 | 0.8604 ± 0.0268 | 0.8547 ± 0.0514 | 0.9201 ± 0.0481 | 0.8954 ± 0.0515 | 0.8470 ± 0.0336 | 0.8210 ± 0.0527 | 0.9020 ± 0.0409 | |
| fixed | 0.9339 ± 0.0081 | 0.8676 ± 0.0097 | 0.8595 ± 0.0163 | 0.9339 ± 0.0081 | 0.9249 ± 0.0165 | 0.8534 ± 0.0235 | 0.8418 ± 0.0315 | 0.9249 ± 0.0165 | |
| fixed | 0.8874 ± 0.0614 | 0.8513 ± 0.0229 | 0.8231 ± 0.0532 | 0.8945 ± 0.0527 | 0.9217 ± 0.0177 | 0.8509 ± 0.0248 | 0.8355 ± 0.0340 | 0.9217 ± 0.0177 | |
| fixed | 0.9088 ± 0.0498 | 0.8590 ± 0.0246 | 0.8391 ± 0.0454 | 0.9118 ± 0.0439 | 0.9301 ± 0.0104 | 0.8612 ± 0.0168 | 0.8510 ± 0.0208 | 0.9301 ± 0.0104 | |
| Scene15 | Variant | 10% | 30% | ||||||
|---|---|---|---|---|---|---|---|---|---|
| ACC | NMI | ARI | PUR | ACC | NMI | ARI | PUR | ||
| Learn ( w/ corr.) | 0.5040 0.0153 | 0.4804 0.0050 | 0.3273 0.0088 | 0.5270 0.0202 | 0.4807 0.0136 | 0.4560 0.0090 | 0.3106 0.0079 | 0.5119 0.0164 | |
| w/o corr. | 0.4863 0.0103 | 0.4780 0.0059 | 0.3192 0.0085 | 0.5021 0.0109 | 0.4678 0.0054 | 0.4440 0.0033 | 0.3097 0.0033 | 0.4823 0.0089 | |
| fixed | 0.4963 0.0142 | 0.4722 0.0069 | 0.3237 0.0105 | 0.5220 0.0128 | 0.4702 0.0077 | 0.4466 0.0037 | 0.2977 0.0041 | 0.4941 0.0095 | |
| fixed | 0.5057 0.0062 | 0.4743 0.0099 | 0.3272 0.0060 | 0.5281 0.0075 | 0.4746 0.0202 | 0.4458 0.0128 | 0.3011 0.0136 | 0.4986 0.0193 | |
| fixed | 0.4963 0.0190 | 0.4673 0.0113 | 0.3214 0.0099 | 0.5218 0.0200 | 0.4689 0.0175 | 0.4414 0.0111 | 0.3005 0.0129 | 0.4891 0.0221 | |
| Methods | ||||||||||
| Dataset | Metric | BSV | CONCAT | DSIMVC | DCP | CPSPAN | DVIMC | MVP | PMIMC | ACOVA |
| Scene15 | Time | - | - | |||||||
| ACC | 0.2593 | 0.2596 | 0.2654 | 0.3784 | 0.2025 | 0.4136 | 0.4407 | 0.3178 | 0.4428 | |
| NoisyMNIST | Time | - | - | |||||||
| ACC | 0.2672 | 0.2805 | 0.6245 | 0.9225 | 0.5486 | 0.8741 | 0.6660 | 0.6044 | 0.9377 | |
| Number of Views ( ) | 2 | 3 | 4 | 5 |
|---|---|---|---|---|
| Runtime (seconds) | 0.18 ± 0.03 | 0.22 ± 0.03 | 0.26 ± 0.04 | 0.27 ± 0.04 |