  Most existing cross-modal generative methods based on diffusion models use
guidance to provide control over the latent space to enable conditional
generation across different modalities. Such methods focus on providing
guidance through separately-trained models, each for one modality. As a result,
these methods suffer from cross-modal information loss and are limited to
unidirectional conditional generation. Inspired by how humans synchronously
acquire multi-modal information and learn the correlation between modalities,
we explore a multi-modal diffusion model training and sampling scheme that uses
channel-wise image conditioning to learn cross-modality correlation during the
training phase to better mimic the learning process in the brain. Our empirical
results demonstrate that our approach can achieve data generation conditioned
on all correlated modalities.
