Referee Can Play: An Alternative Approach to Conditional Generation via Model Inversion
This addresses alignment issues in conditional generation for diffusion models, though it appears incremental as it builds on existing VLMs and sampling techniques.
The paper tackles the challenge of controllability in text-to-image generation by proposing a training-free approach that inverts Vision-Language Models to optimize images directly, achieving near state-of-the-art performance on T2I-Compbench.
As a dominant force in text-to-image generation tasks, Diffusion Probabilistic Models (DPMs) face a critical challenge in controllability, struggling to adhere strictly to complex, multi-faceted instructions. In this work, we aim to address this alignment challenge for conditional generation tasks. First, we provide an alternative view of state-of-the-art DPMs as a way of inverting advanced Vision-Language Models (VLMs). With this formulation, we naturally propose a training-free approach that bypasses the conventional sampling process associated with DPMs. By directly optimizing images with the supervision of discriminative VLMs, the proposed method can potentially achieve a better text-image alignment. As proof of concept, we demonstrate the pipeline with the pre-trained BLIP-2 model and identify several key designs for improved image generation. To further enhance the image fidelity, a Score Distillation Sampling module of Stable Diffusion is incorporated. By carefully balancing the two components during optimization, our method can produce high-quality images with near state-of-the-art performance on T2I-Compbench.