Check, Locate, Rectify: A Training-Free Layout Calibration System for Text-to-Image Generation
Biao Gong, Siteng Huang, Yutong Feng, Shiwei Zhang, Yuyuan Li, Yu Liu
TL;DR
This paper tackles the challenge of aligning text-to-image diffusion outputs with complex layout prompts without additional training. It introduces SimM, a training-free, inference-time system that check-locate-rectifies cross-attention activations to correct misplaced objects, guided by target layouts derived from the prompt via dependency parsing and heuristic rules. Activation transfer and multi-map refinement enable precise repositioning with minimal overhead, and SimMBench provides a benchmark for superlative layout descriptions. Experiments show significant gains in layout fidelity over strong baselines while preserving image quality and achieving near real-time latency, highlighting the practical utility of inference-time layout calibration for diffusion models.
Abstract
Diffusion models have recently achieved remarkable progress in generating realistic images. However, challenges remain in accurately understanding and synthesizing the layout requirements in the textual prompts. To align the generated image with layout instructions, we present a training-free layout calibration system SimM that intervenes in the generative process on the fly during inference time. Specifically, following a "check-locate-rectify" pipeline, the system first analyses the prompt to generate the target layout and compares it with the intermediate outputs to automatically detect errors. Then, by moving the located activations and making intra- and inter-map adjustments, the rectification process can be performed with negligible computational overhead. To evaluate SimM over a range of layout requirements, we present a benchmark SimMBench that compensates for the lack of superlative spatial relations in existing datasets. And both quantitative and qualitative results demonstrate the effectiveness of the proposed SimM in calibrating the layout inconsistencies. Our project page is at https://simm-t2i.github.io/SimM.
