Local Models for Monocular Reconstruction of Deformable 3D Surfaces
Click on the images to jump to corresponding results.
Recovering the 3D shape of a nonrigid surface from a single
viewpoint is known to be both ambiguous and challenging. Resolving the
ambiguities typically requires prior knowledge about the most likely
deformations that the surface may undergo. It often takes the form of a global
deformation model that can be learned from training data. While effective, this
approach suffers from the fact that a new model must be learned for each new
surface, which means acquiring new training data and may be impractical.
In this work, we replaced the global models by linear local ones for surface
patches, which can be assembled to represent arbitrary surface shapes as long as
they are made of the same material. Not only do they eliminate the need to
retrain the model for different surface shapes, they also let us formulate 3D
shape reconstruction from correspondences as either an algebraic problem that
can be solved in closed-form or a convex optimization problem whose solution can
be found using standard numerical packages.
We recover the 3D shape of a deforming surface represented by a triangulated
mesh given point correspondences between one or more input images, in which the
shape is unknown, and a reference image in which it is known.
In each one of the videos below, we show
Top left: The 3D mesh recovered by enforcing temporal consistency across
three-frame sequences and reprojected on the original images.
Bottom left: The same mesh seen from a different viewpoint.
Top right: The mesh recovered from individual frames and without enforcing
temporal consistency, which yields more jittery results.
Bottom right: Results obtained by enforcing temporal consistency across
the whole sequence as a post-processing step, which yields smoother results.
The reference image appears to the left of the videos. This technology has been
used to measure the 3D
shape of sails while underway.
Code from Salzmann and Fua, CVPR 2009. The
linked .tgz file contains the cardboard data also
available here. It
requires the SeDuMi optimization software package that can be downloaded
from here.