Training-Free Structured Diffusion Guidance for Compositional Text-to-Image Synthesis. - Feng, Weixi; He, Xuehai; Fu, Tsu-Jui; Jampani, Varun; Akula, Arjun R.; Narayana, Pradyumna; Basu, Sugato; Wang, Xin Eric; Wang, William Yang (2023)