Generating Images with Multimodal Language Models

Abstract: We propose a method to fuse frozen text-only LLMs with pre-trained image encoder and decoder models, by mapping between their embedding spaces. Our model demonstrates a wide suite of multimodal capabilities: image retrieval, novel image generation, and multimodal dialogue. Ours is the first approach capable of conditioning on arbitrarily interleaved image and text inputs to generate coherent image (and text) outputs. To achieve strong performance on image generation, we propose an efficient mapping network to ground the LLM to an off-the-shelf text-to-image generation model. This mapping network translates hidden representations of text into the embedding space of the visual models, enabling us to leverage the strong text representations of the LLM for visual outputs. Our approach outperforms baseline generation models on tasks with longer and more complex language. In addition to novel image generation, our model is also capable of image retrieval from a prespecified dataset, and decides whether to retrieve or generate at inference time. This is done with a learnt decision module which conditions on the hidden representations of the LLM. Our model exhibits a wider range of capabilities compared to prior multimodal LLMs. It can process image-and-text inputs, and produce retrieved images, generated images, and generated text -- outperforming non-LLM based generation models across several text-to-image tasks that measure context dependence.

• The paper introduces GILL, a method that maps frozen LLM embeddings to a visual decoder’s space for coherent multimodal output.
• It details a lightweight GILLMapper Transformer that efficiently converts text representations to image generation inputs.
• Experimental results on datasets like VIST and VisDial show improved performance on complex multimodal tasks, indicating promising applications in AI.

Generating Images with Multimodal LLMs: An Overview

The paper "Generating Images with Multimodal LLMs" presents an innovative approach to fusing LLMs with pre-trained image encoders and decoders by mapping between their embedding spaces. The authors focus on creating a model that leverages the strengths of LLMs in text processing to extend capabilities to multimodal tasks, such as image retrieval, novel image generation, and multimodal dialogue.

Methodology and Model Architecture

The authors introduce a method called GILL (Generating Images with LLMs), which enables the processing of interleaved image-and-text inputs to generate coherent image and text outputs. The novelty of this approach lies in the efficient mapping network that translates the hidden representations of text into the embedding space of a visual model. This mapping allows the model to generate relevant visual outputs by grounding the LLM to a text-to-image generation model, specifically Stable Diffusion.

The model architecture is designed to keep the majority of the LLM weights frozen, allowing it to leverage the existing capabilities of LLMs learned during text pretraining. The proposed architectural changes involve the introduction of a GILLMapper module, a lightweight Transformer conditioned on special learned text tokens. This module efficiently maps the LLM's output embedding space to the input space of an image generation model, facilitating image synthesis.

Results and Evaluation

Experimental results demonstrate that GILL outperforms baseline models in tasks requiring longer and more complex language contexts. The model's ability to process multimodal context allows it to outperform non-LLM-based generation models, particularly in dialogue-conditioned image generation. The paper provides quantitative results on datasets such as VIST and VisDial, highlighting GILL's improved performance in generating relevant images when conditioned on rich textual and visual context.

Implications and Future Directions

The research provides compelling evidence that integrating LLMs with visual models can expand the capabilities of multimodal LLMs. This approach has significant implications for the future of artificial intelligence, particularly in applications involving AI assistants that require both text processing and image generation capabilities. The ability to produce interleaved multimodal outputs enhances the model's utility in a variety of tasks, from creative endeavors to providing visual content in response to queries.

The modular nature of GILL allows it to potentially benefit from advances in LLMs and visual models, suggesting future directions for scaling up the architecture. This could involve utilizing larger LLMs, more sophisticated image generation backbones, or finetuning on diverse datasets to improve alignment with the visual generation model.

Conclusion

In summary, the paper presents a significant step forward in enhancing the multimodal capabilities of LLMs by grounding them to visual outputs. Through efficient architectural innovations and robust evaluation, the authors demonstrate the potential of GILL in processing and generating image-and-text outputs, providing a promising foundation for future advancements in multimodal AI systems.