PTDiffusion: Free Lunch for Generating Optical Illusion Hidden Pictures with Phase-Transferred Diffusion Model

Xiang Gao, Shuai Yang, Jiaying Liu; Proceedings of the Computer Vision and Pattern Recognition Conference (CVPR), 2025, pp. 18240-18249

Optical illusion hidden picture is an interesting visual perceptual phenomenon where an image is cleverly integrated into another picture. Established on the off-the-shelf text-to-image (T2I) diffusion model, we propose a novel text-guided image-to-image (I2I) translation framework dubbed as Phase-Transferred Diffusion Model (PTDiffusion) for hidden art syntheses, which harmoniously embeds an input reference image into arbitrary scenes described by the text prompts. At the heart of our method is a plug-and-play phase transfer mechanism that dynamically and progressively transplants diffusion features' phase spectrum from the denoising process to reconstruct the reference image into the one to sample the generated illusion image, realizing deep fusion of the reference structural information and the textual semantic information. Furthermore, we propose asynchronous phase transfer to enable flexible control over the degree of hidden content discernability. Our method bypasses any model training and fine-tuning process, all while substantially outperforming related methods in image quality, text fidelity, visual discernibility, and contextual naturalness for illusion picture synthesis, as demonstrated by extensive qualitative and quantitative experiments. Our project is publically available at \href https://xianggao1102.github.io/PTDiffusion_webpage/ this web page .