MotionMaster: Training-free Camera Motion Transfer For Video Generation
Authors: name: Teng Hu, name: Jiangning Zhang, name: Ran Yi, name: Yating Wang, name: Hongrui Huang, name: Jieyu Weng, name: Yabiao Wang, name: Lizhuang Ma

The emergence of diffusion models has greatly propelled the progress in image
and video generation. Recently, some efforts have been made in controllable
video generation, including text-to-video generation and video motion control,
among which camera motion control is an important topic. However, existing
camera motion control methods rely on training a temporal camera module, and
necessitate substantial computation resources due to the large amount of
parameters in video generation models. Moreover, existing methods pre-define
camera motion types during training, which limits their flexibility in camera
control. Therefore, to reduce training costs and achieve flexible camera
control, we propose COMD, a novel training-free video motion transfer model,
which disentangles camera motions and object motions in source videos and
transfers the extracted camera motions to new videos. We first propose a
one-shot camera motion disentanglement method to extract camera motion from a
single source video, which separates the moving objects from the background and
estimates the camera motion in the moving objects region based on the motion in
the background by solving a Poisson equation. Furthermore, we propose a
few-shot camera motion disentanglement method to extract the common camera
motion from multiple videos with similar camera motions, which employs a
window-based clustering technique to extract the common features in temporal
attention maps of multiple videos. Finally, we propose a motion combination
method to combine different types of camera motions together, enabling our
model a more controllable and flexible camera control. Extensive experiments
demonstrate that our training-free approach can effectively decouple
camera-object motion and apply the decoupled camera motion to a wide range of
controllable video generation tasks, achieving flexible and diverse camera
motion control.