  Recent advancements in image generation have enabled the creation of
high-quality images from text conditions. However, when facing multi-modal
conditions, such as text combined with reference appearances, existing methods
struggle to balance multiple conditions effectively, typically showing a
preference for one modality over others. To address this challenge, we
introduce EMMA, a novel image generation model accepting multi-modal prompts
built upon the state-of-the-art text-to-image (T2I) diffusion model, ELLA. EMMA
seamlessly incorporates additional modalities alongside text to guide image
generation through an innovative Multi-modal Feature Connector design, which
effectively integrates textual and supplementary modal information using a
special attention mechanism. By freezing all parameters in the original T2I
diffusion model and only adjusting some additional layers, we reveal an
interesting finding that the pre-trained T2I diffusion model can secretly
accept multi-modal prompts. This interesting property facilitates easy
adaptation to different existing frameworks, making EMMA a flexible and
effective tool for producing personalized and context-aware images and even
videos. Additionally, we introduce a strategy to assemble learned EMMA modules
to produce images conditioned on multiple modalities simultaneously,
eliminating the need for additional training with mixed multi-modal prompts.
Extensive experiments demonstrate the effectiveness of EMMA in maintaining high
fidelity and detail in generated images, showcasing its potential as a robust
solution for advanced multi-modal conditional image generation tasks.
