UniGeo: Taming Video Diffusion for Unified Consistent Geometry
  Estimation
Authors: name: Yang-Tian Sun, name: Xin Yu, name: Zehuan Huang, name: Yi-Hua Huang, name: Yuan-Chen Guo, name: Ziyi Yang, name: Yan-Pei Cao, name: Xiaojuan Qi

Recently, methods leveraging diffusion model priors to assist monocular
geometric estimation (e.g., depth and normal) have gained significant attention
due to their strong generalization ability. However, most existing works focus
on estimating geometric properties within the camera coordinate system of
individual video frames, neglecting the inherent ability of diffusion models to
determine inter-frame correspondence. In this work, we demonstrate that,
through appropriate design and fine-tuning, the intrinsic consistency of video
generation models can be effectively harnessed for consistent geometric
estimation. Specifically, we 1) select geometric attributes in the global
coordinate system that share the same correspondence with video frames as the
prediction targets, 2) introduce a novel and efficient conditioning method by
reusing positional encodings, and 3) enhance performance through joint training
on multiple geometric attributes that share the same correspondence. Our
results achieve superior performance in predicting global geometric attributes
in videos and can be directly applied to reconstruction tasks. Even when
trained solely on static video data, our approach exhibits the potential to
generalize to dynamic video scenes.