๐ค AI Summary
Real-world data often suffer from limited scale and imbalanced subgroup coverage, leading to poor generalization and high bias in classification tasks. To address this, we propose a conditional multimodal data synthesis framework for tabular, textual, and visual modalities, generating high-fidelity, conditionally faithful synthetic samples. Our contributions are threefold: (1) a conditional-distribution-focused synthesis strategy that enables density-adaptive augmentation in sparse regionsโfirst of its kind; (2) a theoretically grounded framework with provable statistical gains, providing rigorous error bounds; and (3) a cross-modal relational preservation mechanism integrating diffusion model fine-tuning, conditional generative modeling, and multimodal alignment. Experiments demonstrate that our method significantly outperforms non-adaptive augmentation and state-of-the-art baselines across both supervised and unsupervised tasks, effectively mitigating data imbalance while improving classification accuracy and domain adaptation performance.
๐ Abstract
Reliable machine learning and statistical analysis rely on diverse, well-distributed training data. However, real-world datasets are often limited in size and exhibit underrepresentation across key subpopulations, leading to biased predictions and reduced performance, particularly in supervised tasks such as classification. To address these challenges, we propose Conditional Data Synthesis Augmentation (CoDSA), a novel framework that leverages generative models, such as diffusion models, to synthesize high-fidelity data for improving model performance across multimodal domains including tabular, textual, and image data. CoDSA generates synthetic samples that faithfully capture the conditional distributions of the original data, with a focus on under-sampled or high-interest regions. Through transfer learning, CoDSA fine-tunes pre-trained generative models to enhance the realism of synthetic data and increase sample density in sparse areas. This process preserves inter-modal relationships, mitigates data imbalance, improves domain adaptation, and boosts generalization. We also introduce a theoretical framework that quantifies the statistical accuracy improvements enabled by CoDSA as a function of synthetic sample volume and targeted region allocation, providing formal guarantees of its effectiveness. Extensive experiments demonstrate that CoDSA consistently outperforms non-adaptive augmentation strategies and state-of-the-art baselines in both supervised and unsupervised settings.