AR-RAG: Autoregressive Retrieval Augmentation for Image Generation
Authors: name: Jingyuan Qi, name: Zhiyang Xu, name: Qifan Wang, name: Lifu Huang

We introduce Autoregressive Retrieval Augmentation (AR-RAG), a novel paradigm
that enhances image generation by autoregressively incorporating knearest
neighbor retrievals at the patch level. Unlike prior methods that perform a
single, static retrieval before generation and condition the entire generation
on fixed reference images, AR-RAG performs context-aware retrievals at each
generation step, using prior-generated patches as queries to retrieve and
incorporate the most relevant patch-level visual references, enabling the model
to respond to evolving generation needs while avoiding limitations (e.g.,
over-copying, stylistic bias, etc.) prevalent in existing methods. To realize
AR-RAG, we propose two parallel frameworks: (1) Distribution-Augmentation in
Decoding (DAiD), a training-free plug-and-use decoding strategy that directly
merges the distribution of model-predicted patches with the distribution of
retrieved patches, and (2) Feature-Augmentation in Decoding (FAiD), a
parameter-efficient fine-tuning method that progressively smooths the features
of retrieved patches via multi-scale convolution operations and leverages them
to augment the image generation process. We validate the effectiveness of
AR-RAG on widely adopted benchmarks, including Midjourney-30K, GenEval and
DPG-Bench, demonstrating significant performance gains over state-of-the-art
image generation models.