OmnimatteZero: Training-free Real-time Omnimatte with Pre-trained Video
  Diffusion Models
Authors: name: Dvir Samuel, name: Matan Levy, name: Nir Darshan, name: Gal Chechik, name: Rami Ben-Ari

Omnimatte aims to decompose a given video into semantically meaningful
layers, including the background and individual objects along with their
associated effects, such as shadows and reflections. Existing methods often
require extensive training or costly self-supervised optimization. In this
paper, we present OmnimatteZero, a training-free approach that leverages
off-the-shelf pre-trained video diffusion models for omnimatte. It can remove
objects from videos, extract individual object layers along with their effects,
and composite those objects onto new videos. We accomplish this by adapting
zero-shot image inpainting techniques for video object removal, a task they
fail to handle effectively out-of-the-box. We then show that self-attention
maps capture information about the object and its footprints and use them to
inpaint the object's effects, leaving a clean background. Additionally, through
simple latent arithmetic, object layers can be isolated and recombined
seamlessly with new video layers to produce new videos. Evaluations show that
OmnimatteZero not only achieves superior performance in terms of background
reconstruction but also sets a new record for the fastest Omnimatte approach,
achieving real-time performance with minimal frame runtime.