Visual Anagrams: Generating Multi-View Optical Illusions with Diffusion Models
Authors: Daniel Geng, Inbum Park, Andrew Owens

We address the problem of synthesizing multi-view optical illusions: images that change appearance upon a transformation such as a flip or rotation. We propose a simple zero-shot method for obtaining these illusions from off-the-shelf text-to-image diffusion models. During the reverse diffusion process we estimate the noise from different views of a noisy image and then combine these noise estimates together and denoise the image. A theoretical analysis suggests that this method works precisely for views that can be written as orthogonal transformations of which permutations are a subset. This leads to the idea of a   visual anagram ---an image that changes appearance under some rearrangement of pixels. This includes rotations and flips but also more exotic pixel permutations such as a jigsaw rearrangement. Our approach also naturally extends to illusions with more than two views. We provide both qualitative and quantitative results demonstrating the effectiveness and flexibility of our method. Please see our project webpage for additional visualizations and results: https://dangeng.github.io/visual_anagrams/