Learning disentangled representations, where semantic features are independently captured in a latent space, is dominated by Variational Auto Encoders (VAE) and Adversarial Training. In this paper, we provide direct quantitative and visual evidence that these methods consistently fail to enforce the target factorized representation on the aggregate posterior, leading to entangled representations. We quantify this failure using the Latent Predictability Score (LPS), an unsupervised metric of mutual predictability that empirically lower bounds the level of entanglement in a latent space. To address these limitations, we leverage the non-parametric Maximum Mean Discrepancy (MMD) to directly sculpt the aggregate posterior enabling programmable priors. We demonstrate (1) state-of-the-art unsupervised statistical independence, with a 70% reduction in detected entanglement compared to leading baselines; (2) the flexibility to optionally inject semi-supervised information for explicit semantic alignment; and (3) precise shaping of the aggregate posterior distribution (validated through quantization-aware training) without sacrificing reconstruction quality.
Figures & tables
Figure 1: Visualizing the Sculpting Framework.
Figure 2: Visual comparison of learned latent distributions on MNIST for key baselines. Each column corresponds to a different model, showing the covariance matrix between the latent space features over the dataset (top row) and the histogram plots for the marginal distribution of the latent space features over the whole dataset (bottom row). The VAE-based models (a, b) and the standard AE (e) fail to enforce either independence or the target Gaussian geometry. While a batch-wise KLD regularizer (d) achieves a diagonal covariance, its parametric nature prevents it from correctly shaping the marginal distributions leading to co-dependence (LPS equal to 0.97). Only the MMD-regularized model (c) successfully enforces both properties, producing a representation that is truly independent and matches the target prior.
Figure 3: Example images (represented in an 8×8 grid) from the synthetic datasets used in our experiments. From left to right: (a) dSprites, with factors like shape, scale, and orientation; (b-d) The XY family of datasets, with factors for position (XY), color (C), and shape (S); (c) The CelebA dataset consisting of faces with 40 different semantic factors.
ImageNet ( d=64 )
CIFAR10 ( d=64 )
MNIST ( d=12 )
dsprites ( d=5 )
XY ( d=2 )
XYC ( d=3 )
XYCS ( d=4 )
celebA ( d=32 )
Model
LPS
NMSE (dB)
LPS
NMSE (dB)
LPS
NMSE (dB)
LPS
NMSE (dB)
LPS
NMSE (dB)
LPS
NMSE (dB)
LPS
NMSE (dB)
LPS
NMSE (dB)
SWAE-MMD (ours)
0.03
-11.70
0.04
-15.61
0.22
-11.92
0.04
-17.89
-0.05
-15.22
-0.01
-16.31
0.11
-16.76
0.08
-14.37
DGAE
0.77
-10.3
0.69
-15.53
0.63
-11.48
0.56
-14.61
0.25
-6.74
0.50
-10.94
0.59
-15.02
0.48
-14.40
NASHAE
0.56
-11.32
0.17
-15.02
0.22
-11.32
0.10
-13.48
-0.07
-13.08
0.14
-14.93
0.37
-13.15
0.36
-13.67
FactorVAE ( γ= 10.0)
0.44
-10.75
0.63
-12.49
0.27
-8.62
0.08
-14.56
-0.04
- 15.36
0.00
-15.92
0.17
-15.52
0.07
-14.39
β -TCVAE ( β= 4.0)
0.79
-9.80
0.89
-10.68
0.84
-5.97
0.22
-8.83
-0.04
-14.68
-0.01
-13.72
0.17
-12.40
0.59
-13.10
Table 1: Main quantitative results comparing our unsupervised MMD-based Autoencoder against baselines (the latent space dimension is specified next to the dataset name). Each cell presents two key metrics: LPS-lgbm ( R2 ) | reconstruction NMSE (dB) where lower values are better ( ↓ ). The best performance for each metric on each dataset is highlighted in bold . Averaged over all 8 datasets, AE-MMD obtains a 70% reduction in detected latent space entanglement compared to Factor VAE, the next best baseline, all while maintaining a better image reconstruction quality.
Figure 4: Aligning the Latent Space to Semantic Features Using The Programmable Prior On dSprites. The plots show the DCI Disentanglement Score (left), the Latent Predictability Score (LPS) using LGBM (middle), and the reconstruction NMSE in decibels (right) as the number of pseudo-labels used for alignment increases. The DCI scores were always evaluated with respect to all 5 semantic features (Shape, Scale, Orientation, X-Position, Y-Position).
Figure 6: Visualization of Alignment Mechanism in Programmable Prior Framework. The figure shows the covariance matrix of the joint distribution p(z,f(u)) for the target (left) and the learned joint distribution (right) with 2 and 4 pseudo-labels respectively on the dsprites dataset.
Figure 8: Compression with the Programmable Prior. We compare the reconstruction NMSE (dB) of our MMD-regularized models against baselines with a uniform (left) or a Gaussian (right) quantizer.
Appendix figures & tables27 assets
Supplementary material from the paper’s appendix.
Appendix
Dataset
Number of Layers
Latent Dimension ( d )
Training Epochs
XY, XYC, XYCS
6, 6, 6
2, 3, 4
500, 250, 125
dSprites
6
5
50
CelebA
6
32
75
MNIST
4
12
250
CIFAR-10
4
64
250
Tiny ImageNet
6
64
75
Appendix
Table 2: Dataset-specific hyperparameters. The "Number of Layers" refers to the depth of the encoder and decoder individually (e.g., "6" indicates 6 layers for the encoder and 6 for the decoder).
L=64
Baseline
Covariance Ratio
LPS_LGBM
LPS_MLP
NMSE_dB
NMSE_linear
AE-MMD-Gaussian (Ours)
54.386 ± 2.220
0.029 ± 0.002
0.001 ± 0.004
-11.704 ± 0.007
0.068 ± 0.000
FactorVAE ( γ =10.0)
2.338 ± 0.286
0.437 ± 0.064
0.483 ± 0.065
-10.754 ± 0.239
0.084 ± 0.005
β -TCVAE ( β =4.0)
4.950 ± 0.264
0.794 ± 0.018
0.932 ± 0.015
-9.798 ± 0.027
0.105 ± 0.001
β -VAE ( β =4)
4.934 ± 0.104
0.726 ± 0.018
0.872 ± 0.035
-9.866 ± 0.009
0.103 ± 0.000
Standard AE
7.699 ± 0.207
0.455 ± 0.006
0.460 ± 0.007
-11.775 ± 0.005
0.066 ± 0.000
Appendix
Table 3: Summary for TINY IMAGENET
L=64
Baseline
Covariance Ratio
LPS_LGBM
LPS_MLP
NMSE_dB
NMSE_linear
AE-MMD-Gaussian (Ours)
65.917 ± 1.788
0.038 ± 0.004
0.025 ± 0.008
-15.615 ± 0.008
0.027 ± 0.000
FactorVAE ( γ =10.0)
3.347 ± 0.075
0.628 ± 0.004
0.788 ± 0.006
-12.491 ± 0.012
0.056 ± 0.000
β -TCVAE ( β =4.0)
10.711 ± 0.350
0.890 ± 0.008
0.953 ± 0.006
-10.684 ± 0.005
0.085 ± 0.000
β -VAE ( β =4)
11.506 ± 0.238
0.846 ± 0.008
0.925 ± 0.006
-10.492 ± 0.006
0.089 ± 0.000
Standard AE
6.929 ± 0.192
0.508 ± 0.005
0.513 ± 0.005
-15.834 ± 0.007
0.026 ± 0.000
Appendix
Table 4: Summary for CIFAR10
L=12
Baseline
Covariance Ratio
LPS_LGBM
LPS_MLP
NMSE_dB
NMSE_linear
AE-MMD-Gaussian (Ours)
46.635 ± 2.442
0.220 ± 0.007
0.333 ± 0.006
-11.922 ± 0.024
0.064 ± 0.000
DGAE
6.191 ± 0.368
0.632 ± 0.002
0.671 ± 0.005
-11.478 ± 0.027
0.071 ± 0.000
NASHAE
47.835 ± 6.503
0.210 ± 0.014
0.407 ± 0.023
-11.389 ± 0.133
0.073 ± 0.002
FactorVAE ( γ =10.0)
2.628 ± 0.094
0.271 ± 0.066
0.275 ± 0.098
-8.621 ± 0.023
0.137 ± 0.001
β -TCVAE ( β =4.0)
8.071 ± 2.238
0.838 ± 0.022
0.893 ± 0.015
-5.967 ± 0.008
0.253 ± 0.000
Appendix
Table 5: Summary for MNIST
L=32
Baseline
NMSE_dB
NMSE_linear
completeness
disentanglement
feature_dependence
informativeness
lps_lgbm
lps_mlp
mig
sap
AE-MMD-Gaussian
-14.370 ± 0.012
0.037 ± 0.000
0.009 ± 0.000
0.008 ± 0.000
61.678 ± 3.671
0.868 ± 0.001
0.080 ± 0.003
0.227 ± 0.009
0.006 ± 0.002
0.000 ± 0.000
DGAE
-14.404 ± 0.016
0.036 ± 0.000
0.014 ± 0.001
0.013 ± 0.001
5.742 ± 0.318
0.873 ± 0.001
0.481 ± 0.011
0.529 ± 0.010
0.011 ± 0.003
0.000 ± 0.000
FactorVAE ( γ =10.0)
-14.394 ± 0.150
0.036 ± 0.001
0.014 ± 0.001
0.013 ± 0.001
62.873 ± 2.077
0.871 ± 0.001
0.071 ± 0.007
0.106 ± 0.018
0.014 ± 0.003
0.000 ± 0.000
NASHAE
-13.672 ± 0.340
0.043 ± 0.003
0.010 ± 0.001
0.009 ± 0.001
18.684 ± 14.394
0.867 ± 0.001
0.362 ± 0.185
0.477 ± 0.181
0.007 ± 0.001
0.000 ± 0.000
Standard AE
-14.546 ± 0.012
0.035 ± 0.000
0.012 ± 0.001
0.012 ± 0.001
7.490 ± 0.169
0.871 ± 0.000
0.441 ± 0.004
0.479 ± 0.005
0.008 ± 0.001
0.000 ± 0.000
Appendix
Table 6: Summary for CELEBA (L=32)
L=64
Baseline
NMSE_dB
NMSE_linear
completeness
disentanglement
feature_dependence
informativeness
lps_lgbm
lps_mlp
mig
sap
AE-MMD-Gaussian
-16.087 ± 0.011
0.025 ± 0.000
0.011 ± 0.001
0.012 ± 0.001
63.822 ± 2.724
0.866 ± 0.001
0.097 ± 0.003
0.309 ± 0.007
0.004 ± 0.001
0.000 ± 0.000
DGAE
-15.894 ± 0.030
0.026 ± 0.000
0.019 ± 0.002
0.021 ± 0.003
7.992 ± 0.522
0.874 ± 0.001
0.498 ± 0.008
0.839 ± 0.079
0.012 ± 0.005
0.000 ± 0.000
FactorVAE ( γ =10.0)
-14.885 ± 0.088
0.032 ± 0.001
0.018 ± 0.002
0.020 ± 0.002
89.942 ± 7.703
0.871 ± 0.001
0.566 ± 0.007
0.829 ± 0.016
0.013 ± 0.002
0.000 ± 0.000
NASHAE
-13.557 ± 1.355
0.046 ± 0.014
0.011 ± 0.001
0.013 ± 0.001
8.334 ± 3.465
0.866 ± 0.000
0.759 ± 0.185
0.930 ± 0.067
0.008 ± 0.003
0.000 ± 0.000
Standard AE
-16.251 ± 0.016
0.024 ± 0.000
0.015 ± 0.001
0.017 ± 0.001
8.984 ± 0.336
0.870 ± 0.000
0.516 ± 0.007
0.566 ± 0.007
0.007 ± 0.001
0.000 ± 0.000
Appendix
Table 7: Summary for CELEBA (L=64)
L=5
Baseline
Covariance Ratio
LPS_LGBM
LPS_MLP
MIG_mig_score
NMSE_dB
NMSE_linear
SAP_sap_score
completeness
disentanglement
informativeness
AE-MMD-Gaussian (Ours)
102.265 ± 21.202
0.039 ± 0.002
0.033 ± 0.006
0.058 ± 0.024
-17.888 ± 0.281
0.016 ± 0.001
0.000 ± 0.000
0.026 ± 0.018
0.025 ± 0.017
0.950 ± 0.002
AE-MMD-hybrid-sampler (Ours)
263.218 ± 87.577
0.105 ± 0.008
0.087 ± 0.012
0.247 ± 0.030
-16.311 ± 0.261
0.023 ± 0.001
0.246 ± 0.027
0.200 ± 0.038
0.196 ± 0.038
0.957 ± 0.001
DGAE
4.065 ± 1.233
0.557 ± 0.112
0.573 ± 0.147
0.261 ± 0.198
-14.614 ± 2.173
0.040 ± 0.026
0.000 ± 0.000
0.226 ± 0.104
0.219 ± 0.101
0.962 ± 0.004
FactorVAE ( γ =10.0)
8.477 ± 1.004
0.082 ± 0.010
0.053 ± 0.017
0.226 ± 0.079
-14.564 ± 0.110
0.035 ± 0.001
0.000 ± 0.000
0.081 ± 0.033
0.079 ± 0.032
0.964 ± 0.004
β -TCVAE ( β =4.0)
6.469 ± 4.162
0.223 ± 0.165
0.180 ± 0.182
0.408 ± 0.215
-8.831 ± 0.085
0.131 ± 0.003
0.000 ± 0.000
0.212 ± 0.119
0.195 ± 0.105
0.960 ± 0.005
Appendix
Table 8: Summary for DSPRITES
L=2
Baseline
Covariance Ratio
LPS_LGBM
LPS_MLP
MIG_mig_score
NMSE_dB
NMSE_linear
SAP_sap_score
completeness
disentanglement
informativeness
AE-MMD-Gaussian (Ours)
240.970 ± 243.891
-0.053 ± 0.007
-0.004 ± 0.003
0.751 ± 0.554
-15.222 ± 0.403
0.030 ± 0.003
0.423 ± 0.316
0.199 ± 0.244
0.199 ± 0.243
1.000 ± 0.000
AE-MMD-hybrid-sampler (Ours)
380.827 ± 408.352
-0.065 ± 0.020
-0.003 ± 0.005
1.047 ± 0.414
-15.825 ± 0.154
0.026 ± 0.001
0.713 ± 0.139
0.471 ± 0.230
0.469 ± 0.233
1.000 ± 0.000
DGAE
16.631 ± 19.417
0.248 ± 0.380
0.241 ± 0.385
1.580 ± 1.414
-6.742 ± 2.522
0.262 ± 0.206
0.000 ± 0.000
0.521 ± 0.435
0.521 ± 0.435
0.999 ± 0.001
NASHAE
52.672 ± 22.762
-0.066 ± 0.012
0.007 ± 0.004
0.124 ± 0.059
-13.082 ± 0.849
0.050 ± 0.010
0.325 ± 0.186
0.134 ± 0.144
0.131 ± 0.142
0.999 ± 0.001
FactorVAE ( γ =10.0)
2.022 ± 1.392
-0.040 ± 0.011
0.015 ± 0.013
0.693 ± 0.545
-15.364 ± 0.359
0.029 ± 0.002
0.537 ± 0.268
0.337 ± 0.255
0.336 ± 0.255
1.000 ± 0.000
Appendix
Table 9: Summary for XY
L=3
Baseline
Covariance Ratio
LPS_LGBM
LPS_MLP
MIG_mig_score
NMSE_dB
NMSE_linear
SAP_sap_score
completeness
disentanglement
informativeness
AE-MMD-Gaussian (Ours)
49.341 ± 12.168
-0.014 ± 0.016
0.016 ± 0.007
0.256 ± 0.118
-16.311 ± 0.245
0.023 ± 0.001
0.237 ± 0.077
0.115 ± 0.039
0.113 ± 0.038
0.999 ± 0.000
AE-MMD-hybrid-sampler (Ours)
324.644 ± 274.142
0.168 ± 0.030
0.117 ± 0.035
0.465 ± 0.336
-15.962 ± 0.205
0.025 ± 0.001
0.266 ± 0.240
0.228 ± 0.224
0.227 ± 0.224
1.000 ± 0.000
DGAE
4.802 ± 2.926
0.498 ± 0.417
0.503 ± 0.414
0.340 ± 0.181
-10.936 ± 3.421
0.110 ± 0.083
0.000 ± 0.000
0.184 ± 0.105
0.175 ± 0.098
0.996 ± 0.005
NASHAE
16.476 ± 5.414
0.145 ± 0.091
0.138 ± 0.084
0.048 ± 0.004
-14.933 ± 0.701
0.033 ± 0.005
0.217 ± 0.080
0.095 ± 0.035
0.094 ± 0.034
0.999 ± 0.000
FactorVAE ( γ =10.0)
1.581 ± 0.076
-0.000 ± 0.006
0.032 ± 0.005
0.140 ± 0.059
-15.919 ± 0.219
0.026 ± 0.001
0.183 ± 0.157
0.079 ± 0.069
0.076 ± 0.065
1.000 ± 0.000
Appendix
Table 10: Summary for XYC
L=4
Baseline
Covariance Ratio
LPS_LGBM
LPS_MLP
MIG_mig_score
NMSE_dB
NMSE_linear
SAP_sap_score
completeness
disentanglement
informativeness
AE-MMD-Gaussian (Ours)
42.117 ± 2.445
0.111 ± 0.011
0.106 ± 0.020
0.092 ± 0.036
-16.757 ± 0.143
0.021 ± 0.001
0.110 ± 0.032
0.048 ± 0.016
0.048 ± 0.016
0.997 ± 0.000
AE-MMD-hybrid-sampler (Ours)
133.148 ± 52.617
0.203 ± 0.021
0.151 ± 0.025
0.235 ± 0.070
-16.101 ± 0.283
0.025 ± 0.002
0.278 ± 0.060
0.149 ± 0.051
0.146 ± 0.050
0.998 ± 0.000
DGAE
7.087 ± 3.365
0.586 ± 0.235
0.583 ± 0.233
0.275 ± 0.159
-15.023 ± 0.701
0.032 ± 0.005
0.000 ± 0.000
0.190 ± 0.076
0.187 ± 0.074
0.997 ± 0.001
NASHAE
8.577 ± 4.533
0.368 ± 0.026
0.383 ± 0.023
0.040 ± 0.009
-13.152 ± 0.681
0.049 ± 0.007
0.168 ± 0.007
0.145 ± 0.043
0.143 ± 0.044
0.997 ± 0.001
FactorVAE ( γ =10.0)
1.609 ± 0.127
0.167 ± 0.020
0.165 ± 0.032
0.176 ± 0.114
-15.517 ± 0.366
0.028 ± 0.002
0.192 ± 0.090
0.149 ± 0.098
0.148 ± 0.097
0.997 ± 0.001
Appendix
Table 11: Summary for XYCS
Figure 9: The Paradox of Independence vs. Alignment. Each point represents a model. The ideal model would be in the bottom-right (high alignment, high independence). We observe that models like DGAE occupy the unfavorable top-left quadrant, achieving a high DCI score only by sacrificing independence. Our method (with a Gaussian prior) occupies the bottom-left, prioritizing true independence over potentially flawed alignment metrics.
dsprites
xy
xyc
xycs
Baseline
Disent. ( ↑ )
LPS ( ↓ )
Disent. ( ↑ )
LPS ( ↓ )
Disent. ( ↑ )
LPS ( ↓ )
Disent. ( ↑ )
LPS ( ↓ )
AE-MMD-Gaussian
0.025
0.039
0.199
-0.053
0.113
-0.014
0.048
0.111
AE-MMD-hybrid
0.196
0.105
0.469
-0.065
0.227
0.168
0.146
0.203
DGAE
0.219
0.557
0.521
0.248
0.175
0.498
0.187
0.596
FactorVAE
0.079
0.082
0.336
-0.040
0.076
-0.000
0.148
0.187
β -TCVAE
0.195
0.222
0.368
-0.042
0.090
-0.010
0.245
0.171
Appendix
Table 12: Comparison of Disentanglement (DCI) and Latent Predictability Score (LPS) across models and synthetic datasets. For Disentanglement, higher is better ( ↑ ), and for LPS, lower is better ( ↓ ).
Figure 10: Comparison of metric stability across 5 random seeds. The error bars represent one standard deviation. (a) The DCI scores exhibit extremely high variance, with the standard deviation often being as large as the mean itself, highlighting the metric’s unreliability. (b) In stark contrast, our proposed LPS metric shows minimal variance, demonstrating its stability and reliability as an intrinsic measure of representation quality.
Figure 11: Latent Independence vs. Latent Space Dimension on CIFAR-10. The plots show the reconstruction NMSE in decibels (left), and the Latent Predictability Score (LPS) using MLP (middle) and LGBM (right) regression as the size of the latent bottleneck increases. Lower scores are better for all metrics. Our method (AE-MMD-Gauss, green line) maintains a high degree of independence across all dimensions, while most baselines learn increasingly entangled representations. Moreover, we achieve this stability at no significant cost to reconstruction error, which is surpassed only by the unregularized standard AE model.
Figure 12: Ablation Study on CIFAR-10: Regularization Coefficient and Batch Size. We report the LPS-lgbm score and the test reconstruction NMSE (dB) against regularization coefficients ranging from 0.1 to 5 (left), and training batch sizes ranging from 64 to 2048 (right).
Figure 13: Ablation Study of Kernel Type on CIFAR-10. We report a scatter plot of the LPS-lgbm score versus the test reconstruction NMSE (dB) for exponential, quadratic, and Gaussian (RBF) kernel types. We also compare configurations with different numbers of bandwidths for kernel averaging according to the median heuristic.
Figure 14: Qualitative Comparison on the XY Dataset. Each column compares the learned latent marginals (top) with the corresponding latent traversals (bottom). (a) Our MMD-trained model successfully learns the true uniform distribution, which results in clean, disentangled traversals. (b) In contrast, the standard AE defaults to a uni-modal distribution, leading to entangled traversals.
Prior
NMSE (dB)
LPS-lgbm
LPS-mlp
DCI-RF
MIG
AE-Gaussian
-15.2
-0.053
-0.004
0.199
0.751
AE-Uniform
-15.8
-0.064
-0.003
0.469
1.047
AE-GMM (2 component)
-14.9
-0.051
0.000
0.251
0.863
Appendix
Table 13: Results for our MMD-based Autoencoder on the XY dataset with different engineered prior distributions. We find selecting a Uniform target prior significantly improve alignment metrics.
Figure 15: Learned marginal distributions for the AE-MMD-hybrid-sampler on dSprites. The histograms provide direct visual proof that the model successfully learned to match the specified target distributions for each latent dimension.
L=5
Baseline
Covariance Ratio
LPS_LGBM
LPS_MLP
MIG_mig_score
NMSE_dB
NMSE_linear
SAP_sap_score
completeness
disentanglement
informativeness
AE-MMD-Gaussian
102.265 ± 21.202
0.039 ± 0.002
0.033 ± 0.006
0.058 ± 0.024
-17.888 ± 0.281
0.016 ± 0.001
0.000 ± 0.000
0.026 ± 0.018
0.025 ± 0.017
0.950 ± 0.002
AE-MMD-hybrid-sampler
263.218 ± 87.577
0.105 ± 0.008
0.087 ± 0.012
0.247 ± 0.030
-16.311 ± 0.261
0.023 ± 0.001
0.246 ± 0.027
0.200 ± 0.038
0.196 ± 0.038
0.957 ± 0.001
Appendix
Table 14: Summary for DSPRITES
L=2
Baseline
Covariance Ratio
LPS_LGBM
LPS_MLP
MIG_mig_score
NMSE_dB
NMSE_linear
SAP_sap_score
completeness
disentanglement
informativeness
AE-MMD-Gaussian
240.970 ± 243.891
-0.053 ± 0.007
-0.004 ± 0.003
0.751 ± 0.554
-15.222 ± 0.403
0.030 ± 0.003
0.423 ± 0.316
0.199 ± 0.244
0.199 ± 0.243
1.000 ± 0.000
AE-MMD-hybrid-sampler
380.827 ± 408.352
-0.065 ± 0.020
-0.003 ± 0.005
1.047 ± 0.414
-15.825 ± 0.154
0.026 ± 0.001
0.713 ± 0.139
0.471 ± 0.230
0.469 ± 0.233
1.000 ± 0.000
Appendix
Table 15: Summary for XY
Figure 16: Learned marginal distributions for the AE-MMD-hybrid-sampler on XYC.
L=3
Baseline
Covariance Ratio
LPS_LGBM
LPS_MLP
MIG_mig_score
NMSE_dB
NMSE_linear
SAP_sap_score
completeness
disentanglement
informativeness
AE-MMD-Gaussian
49.341 ± 12.168
-0.014 ± 0.016
0.016 ± 0.007
0.256 ± 0.118
-16.311 ± 0.245
0.023 ± 0.001
0.237 ± 0.077
0.115 ± 0.039
0.113 ± 0.038
0.999 ± 0.000
AE-MMD-hybrid-sampler
324.644 ± 274.142
0.168 ± 0.030
0.117 ± 0.035
0.465 ± 0.336
-15.962 ± 0.205
0.025 ± 0.001
0.266 ± 0.240
0.228 ± 0.224
0.227 ± 0.224
1.000 ± 0.000
Appendix
Table 16: Summary for XYC
Figure 17: Learned marginal distributions for the AE-MMD-hybrid-sampler on XYCS.
L=4
Baseline
Covariance Ratio
LPS_LGBM
LPS_MLP
MIG_mig_score
NMSE_dB
NMSE_linear
SAP_sap_score
completeness
disentanglement
informativeness
AE-MMD-Gaussian
42.117 ± 2.445
0.111 ± 0.011
0.106 ± 0.020
0.092 ± 0.036
-16.757 ± 0.143
0.021 ± 0.001
0.110 ± 0.032
0.048 ± 0.016
0.048 ± 0.016
0.997 ± 0.000
AE-MMD-hybrid-sampler
133.148 ± 52.617
0.203 ± 0.021
0.151 ± 0.025
0.235 ± 0.070
-16.101 ± 0.283
0.025 ± 0.002
0.278 ± 0.060
0.149 ± 0.051
0.146 ± 0.050
0.998 ± 0.000
Appendix
Table 17: Summary for XYCS
Figure 18: Visualizing the Latent Space Copying experiment on MNIST. (b) First, a standard Autoencoder was trained, and its complex, entangled latent distribution was saved to serve as an empirical prior. (a) Then, a new "student" model was trained using our MMD-based sculpting regularizer, tasked with replicating this non-analytic prior. The figure displays the covariance matrix between the latent space features over the whole dataset and the histogram plots of the marginal distribution of the latent space features over the whole dataset. The near-identical covariance matrices and marginal distributions visually confirm our method’s ability to enforce a complex, co-dependent latent geometry that would be impossible to specify analytically.
Figure 19: Failure of Knowledge Transfer via Aggregate Posterior Matching. (Left) Our MMD regularizer successfully forces a "student" model to replicate the latent distribution of a "teacher" model. (Right) Despite this, latent traversals show that the semantic meaning of the latent dimensions is completely different. For the same inputs (connected by lines), traversing a latent feature produces different visual changes, demonstrating that the underlying representations are not the same.
Evaluating and interpreting latent representations, such as variational autoencoders (VAEs), remains a significant challenge for diverse data types, especially when ground-truth generative factors are unknown. To address this, we unify several state-of-the-art disentangled VAE approaches for latent space disentanglement into one framework -- bfVAE. To assess the effectiveness of a disentangled VAE model and enhance latent space interpretability, we propose Feature Variance Heterogeneity via Latent Traversal (FVH-LT) and Dirty Block Sparse Regression in Latent Space (DBSR-LS). To ensure robust interpretability of learned latent space, we develop a greedy alignment strategy (GAS) that mitigates label switching and aligns latent dimensions across runs to set the foundation of result aggregation. We also introduce a convenient scalar latent space separation index (LSSI) based on the GAS-aligned outputs of FVH-LT and DBSR-LS to summarize the overall latent structural separation without knowledge of the ground-truth generative factors. We compare bfVAE to five VAE models and validate the effectiveness FVH-LT, DBSR-LS, and LSSI in on seven tabular and image datasets. Under our examined experimental settings, bfVAE provides a more flexible disentanglement framework achieves more favorable overall trade-off between disentanglement and reconstruction than the benchmark VAE models; FVH-LT and DBSR-LS reliably uncover semantically meaningful and domain-relevant latent structures and generally yield consistent results; and LSSI makes an effective quantitative summary of latent structural separation.
Xiaoan Lang, Md Mostafizer Rahman, Fang Liu
Department of Applied and Computational Mathematics and Statistics University of Notre Dame, Notre Dame, IN, USA · Lucy Family Institute for Data & Society University of Notre Dame, Notre Dame, IN, USA
Disentangled representation learning aims to map independent factors of variation to independent representation components. On one hand, purely unsupervised approaches have proven successful on fully disentangled synthetic data, but fail to recover semantic factors from real data without strong inductive biases. On the other hand, supervised approaches are unstable and hard to scale to large attribute sets because they rely on adversarial objectives or auxiliary classifiers. We introduce XFactors, a weakly-supervised VAE framework that disentangles and provides explicit control over a chosen set of factors. Building on the Disentangled Information Bottleneck perspective, we decompose the representation into a residual subspace S and factor-specific subspaces T1,…,TK and a residual subspace S. Each target factor is encoded in its assigned Ti through contrastive supervision: an InfoNCE loss pulls together latents sharing the same factor value and pushes apart mismatched pairs. In parallel, KL regularization imposes a Gaussian structure on both S and the aggregated factor subspaces, organizing the geometry without additional supervision for non-targeted factors and avoiding adversarial training and classifiers. Across multiple datasets, with constant hyperparameters, XFactors achieves state-of-the-art disentanglement scores and yields consistent qualitative factor alignment in the corresponding subspaces, enabling controlled factor swapping via latent replacement. We further demonstrate that our method scales correctly with increasing latent capacity and evaluate it on the real-world dataset CelebA. Our code is available at github.com/ICML26-anon/XFactors.
Alexandre Myara, Nicolas Bourriez, Thomas Boyer +3
Disentangled representation learning seeks latent representations whose indicidual dimensions each align with a distinct covariate. Unsupervised approaches typically target latent dimension independence, yet this gives no guarantee that the resulting dimensions align with semantically meaningful covariates. Supervised approaches structure the latent space using observed covariates, but under correlated covariates they cannot simultaneously control one-to-one latent-covariate alignment and latent independence. We introduce a unified, supervised framework that couples latent dimension-covariate dependence with constraints on the latent structure. Within this framework, we show an inherent trade-off, where enforcing latent independence or exclusive one-to-one latent-covariate dependence comes at a provable cost in latent-covariate alignment. We prove that the resulting disentanglement regimes are ordered by the strength of that alignment. Each regime admits a closed-form transformation of the latent space. We apply these transformations post-hoc to realign the representations of pretrained models such as CLIP, DINOv2, and ViT, and we fold them into the inference of informed factor analysis (iFA), a probabilistic model with covariate-informed factors. On simulated and real multi-omics data, we show that both post-hoc alignment and iFA enable controllability of structured latent representations.
Małgorzata Łazęcka, Ewa Szczurek
Faculty of Mathematics, Informatics, and Mechanics, University of Warsaw Warsaw, Poland · Institute of AI for Health, Helmholtz Munich Munich, Germany