7,215 research outputs found
A new bandwidth adaptive non-local kernel regression algorithm for image/video restoration and its GPU realization
This paper presents a new bandwidth adaptive nonlocal kernel regression (BA-NLKR) algorithm for image and video restoration. NLKR is a recent approach for improving the performance of conventional steering kernel regression (SKR) and local polynomial regression (LPR) in image/video processing. Its bandwidth, which controls the amount of smoothing, however is chosen empirically. The proposed algorithm incorporates the intersecting confidence intervals (ICI) bandwidth selection method into the framework of NLKR to facilitate automatic bandwidth selection so as to achieve better performance. A parallel implementation of the proposed algorithm is also introduced to reduce significantly its computation time. The effectiveness of the proposed algorithm is illustrated by experimental results on both single image and videos super resolution and denoising.published_or_final_versio
An Efficient Algorithm for Video Super-Resolution Based On a Sequential Model
In this work, we propose a novel procedure for video super-resolution, that
is the recovery of a sequence of high-resolution images from its low-resolution
counterpart. Our approach is based on a "sequential" model (i.e., each
high-resolution frame is supposed to be a displaced version of the preceding
one) and considers the use of sparsity-enforcing priors. Both the recovery of
the high-resolution images and the motion fields relating them is tackled. This
leads to a large-dimensional, non-convex and non-smooth problem. We propose an
algorithmic framework to address the latter. Our approach relies on fast
gradient evaluation methods and modern optimization techniques for
non-differentiable/non-convex problems. Unlike some other previous works, we
show that there exists a provably-convergent method with a complexity linear in
the problem dimensions. We assess the proposed optimization method on {several
video benchmarks and emphasize its good performance with respect to the state
of the art.}Comment: 37 pages, SIAM Journal on Imaging Sciences, 201
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