73 research outputs found
Total Variation Regularized Tensor RPCA for Background Subtraction from Compressive Measurements
Background subtraction has been a fundamental and widely studied task in
video analysis, with a wide range of applications in video surveillance,
teleconferencing and 3D modeling. Recently, motivated by compressive imaging,
background subtraction from compressive measurements (BSCM) is becoming an
active research task in video surveillance. In this paper, we propose a novel
tensor-based robust PCA (TenRPCA) approach for BSCM by decomposing video frames
into backgrounds with spatial-temporal correlations and foregrounds with
spatio-temporal continuity in a tensor framework. In this approach, we use 3D
total variation (TV) to enhance the spatio-temporal continuity of foregrounds,
and Tucker decomposition to model the spatio-temporal correlations of video
background. Based on this idea, we design a basic tensor RPCA model over the
video frames, dubbed as the holistic TenRPCA model (H-TenRPCA). To characterize
the correlations among the groups of similar 3D patches of video background, we
further design a patch-group-based tensor RPCA model (PG-TenRPCA) by joint
tensor Tucker decompositions of 3D patch groups for modeling the video
background. Efficient algorithms using alternating direction method of
multipliers (ADMM) are developed to solve the proposed models. Extensive
experiments on simulated and real-world videos demonstrate the superiority of
the proposed approaches over the existing state-of-the-art approaches.Comment: To appear in IEEE TI
A Non-Local Structure Tensor Based Approach for Multicomponent Image Recovery Problems
Non-Local Total Variation (NLTV) has emerged as a useful tool in variational
methods for image recovery problems. In this paper, we extend the NLTV-based
regularization to multicomponent images by taking advantage of the Structure
Tensor (ST) resulting from the gradient of a multicomponent image. The proposed
approach allows us to penalize the non-local variations, jointly for the
different components, through various matrix norms with .
To facilitate the choice of the hyper-parameters, we adopt a constrained convex
optimization approach in which we minimize the data fidelity term subject to a
constraint involving the ST-NLTV regularization. The resulting convex
optimization problem is solved with a novel epigraphical projection method.
This formulation can be efficiently implemented thanks to the flexibility
offered by recent primal-dual proximal algorithms. Experiments are carried out
for multispectral and hyperspectral images. The results demonstrate the
interest of introducing a non-local structure tensor regularization and show
that the proposed approach leads to significant improvements in terms of
convergence speed over current state-of-the-art methods
Tensor Robust PCA with Nonconvex and Nonlocal Regularization
Tensor robust principal component analysis (TRPCA) is a promising way for
low-rank tensor recovery, which minimizes the convex surrogate of tensor rank
by shrinking each tensor singular values equally. However, for real-world
visual data, large singular values represent more signifiant information than
small singular values. In this paper, we propose a nonconvex TRPCA (N-TRPCA)
model based on the tensor adjustable logarithmic norm. Unlike TRPCA, our
N-TRPCA can adaptively shrink small singular values more and shrink large
singular values less. In addition, TRPCA assumes that the whole data tensor is
of low rank. This assumption is hardly satisfied in practice for natural visual
data, restricting the capability of TRPCA to recover the edges and texture
details from noisy images and videos. To this end, we integrate nonlocal
self-similarity into N-TRPCA, and further develop a nonconvex and nonlocal
TRPCA (NN-TRPCA) model. Specifically, similar nonlocal patches are grouped as a
tensor and then each group tensor is recovered by our N-TRPCA. Since the
patches in one group are highly correlated, all group tensors have strong
low-rank property, leading to an improvement of recovery performance.
Experimental results demonstrate that the proposed NN-TRPCA outperforms some
existing TRPCA methods in visual data recovery. The demo code is available at
https://github.com/qguo2010/NN-TRPCA.Comment: 19 pages, 7 figure
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