47,875 research outputs found
Strain Analysis by a Total Generalized Variation Regularized Optical Flow Model
In this paper we deal with the important problem of estimating the local
strain tensor from a sequence of micro-structural images realized during
deformation tests of engineering materials. Since the strain tensor is defined
via the Jacobian of the displacement field, we propose to compute the
displacement field by a variational model which takes care of properties of the
Jacobian of the displacement field. In particular we are interested in areas of
high strain. The data term of our variational model relies on the brightness
invariance property of the image sequence. As prior we choose the second order
total generalized variation of the displacement field. This prior splits the
Jacobian of the displacement field into a smooth and a non-smooth part. The
latter reflects the material cracks. An additional constraint is incorporated
to handle physical properties of the non-smooth part for tensile tests. We
prove that the resulting convex model has a minimizer and show how a
primal-dual method can be applied to find a minimizer. The corresponding
algorithm has the advantage that the strain tensor is directly computed within
the iteration process. Our algorithm is further equipped with a coarse-to-fine
strategy to cope with larger displacements. Numerical examples with simulated
and experimental data demonstrate the very good performance of our algorithm.
In comparison to state-of-the-art engineering software for strain analysis our
method can resolve local phenomena much better
Simultaneous Stereo Video Deblurring and Scene Flow Estimation
Videos for outdoor scene often show unpleasant blur effects due to the large
relative motion between the camera and the dynamic objects and large depth
variations. Existing works typically focus monocular video deblurring. In this
paper, we propose a novel approach to deblurring from stereo videos. In
particular, we exploit the piece-wise planar assumption about the scene and
leverage the scene flow information to deblur the image. Unlike the existing
approach [31] which used a pre-computed scene flow, we propose a single
framework to jointly estimate the scene flow and deblur the image, where the
motion cues from scene flow estimation and blur information could reinforce
each other, and produce superior results than the conventional scene flow
estimation or stereo deblurring methods. We evaluate our method extensively on
two available datasets and achieve significant improvement in flow estimation
and removing the blur effect over the state-of-the-art methods.Comment: Accepted to IEEE International Conference on Computer Vision and
Pattern Recognition (CVPR) 201
DeepMatching: Hierarchical Deformable Dense Matching
We introduce a novel matching algorithm, called DeepMatching, to compute
dense correspondences between images. DeepMatching relies on a hierarchical,
multi-layer, correlational architecture designed for matching images and was
inspired by deep convolutional approaches. The proposed matching algorithm can
handle non-rigid deformations and repetitive textures and efficiently
determines dense correspondences in the presence of significant changes between
images. We evaluate the performance of DeepMatching, in comparison with
state-of-the-art matching algorithms, on the Mikolajczyk (Mikolajczyk et al
2005), the MPI-Sintel (Butler et al 2012) and the Kitti (Geiger et al 2013)
datasets. DeepMatching outperforms the state-of-the-art algorithms and shows
excellent results in particular for repetitive textures.We also propose a
method for estimating optical flow, called DeepFlow, by integrating
DeepMatching in the large displacement optical flow (LDOF) approach of Brox and
Malik (2011). Compared to existing matching algorithms, additional robustness
to large displacements and complex motion is obtained thanks to our matching
approach. DeepFlow obtains competitive performance on public benchmarks for
optical flow estimation
- …