  In this paper, we demonstrate a fully automatic method for converting a still
image into a realistic animated looping video. We target scenes with continuous
fluid motion, such as flowing water and billowing smoke. Our method relies on
the observation that this type of natural motion can be convincingly reproduced
from a static Eulerian motion description, i.e. a single, temporally constant
flow field that defines the immediate motion of a particle at a given 2D
location. We use an image-to-image translation network to encode motion priors
of natural scenes collected from online videos, so that for a new photo, we can
synthesize a corresponding motion field. The image is then animated using the
generated motion through a deep warping technique: pixels are encoded as deep
features, those features are warped via Eulerian motion, and the resulting
warped feature maps are decoded as images. In order to produce continuous,
seamlessly looping video textures, we propose a novel video looping technique
that flows features both forward and backward in time and then blends the
results. We demonstrate the effectiveness and robustness of our method by
applying it to a large collection of examples including beaches, waterfalls,
and flowing rivers.
