๐ค AI Summary
Existing diffusion models for multimodal joint generation rely on pretrained tokenizers or VAEs to map heterogeneous data into a unified unimodal representation, rendering them sensitive to encoder-decoder fidelity and limiting generalization. This work introduces the first multimodal diffusion framework operable over arbitrary state spacesโenabling text-image joint generation and hybrid tabular data synthesis without requiring modality pre-alignment. Our core innovation is a cross-modal decoupled noise scheduling mechanism, unifying unconditional generation with conditional generation given any subset of modalities within a single model. The method integrates multimodal diffusion modeling, state-space-agnostic stochastic differential equation solvers, and end-to-end joint optimization. Experiments demonstrate state-of-the-art performance on both tasks, significantly reducing dependence on large-scale labeled datasets and high-fidelity encoders/decoders.
๐ Abstract
Diffusion models have demonstrated remarkable performance in generating unimodal data across various tasks, including image, video, and text generation. On the contrary, the joint generation of multimodal data through diffusion models is still in the early stages of exploration. Existing approaches heavily rely on external preprocessing protocols, such as tokenizers and variational autoencoders, to harmonize varied data representations into a unified, unimodal format. This process heavily demands the high accuracy of encoders and decoders, which can be problematic for applications with limited data. To lift this restriction, we propose a novel framework for building multimodal diffusion models on arbitrary state spaces, enabling native generation of coupled data across different modalities. By introducing an innovative decoupled noise schedule for each modality, we enable both unconditional and modality-conditioned generation within a single model simultaneously. We empirically validate our approach for text-image generation and mixed-type tabular data synthesis, demonstrating that it achieves competitive performance.