8,469 research outputs found
Divide-and-conquer framework for image restoration and enhancement
Abstract(#br)We develop a novel divide-and-conquer framework for image restoration and enhancement based on their task-driven requirements, which takes advantage of visual importance differences of image contents (i.e., noise versus image, edge-based structures versus smoothing areas, high-frequency versus low-frequency components) and sparse prior differences of image contents for performance improvements. The proposed framework is efficient in implementation of decomposition-processing-integration. An observed image is first decomposed into different subspaces based on considering visual importance of different subspaces and exploiting their prior differences. Different models are separately established for image subspace restoration and enhancement, and existing image restoration and enhancement methods are utilized to deal with them effectively. Then a simple but effective fusion scheme with different weights is used to integrate the post-processed subspaces for the final reconstructed image. Final experimental results demonstrate that the proposed divide-and-conquer framework outperforms several restoration and enhancement algorithms in both subjective results and objective assessments. The performance improvements of image restoration and enhancement can be yielded by using the proposed divide-and-conquer strategy, which greatly benefits in terms of mixed Gaussian and salt-and-pepper noise removal, non-blind deconvolution, and image enhancement. In addition, our divide-and-conquer framework can be simply extensible to other restoration and enhancement algorithms, and can be a new way to promote their performances for image restoration and enhancement
Large-Scale Sensor Network Localization via Rigid Subnetwork Registration
In this paper, we describe an algorithm for sensor network localization (SNL)
that proceeds by dividing the whole network into smaller subnetworks, then
localizes them in parallel using some fast and accurate algorithm, and finally
registers the localized subnetworks in a global coordinate system. We
demonstrate that this divide-and-conquer algorithm can be used to leverage
existing high-precision SNL algorithms to large-scale networks, which could
otherwise only be applied to small-to-medium sized networks. The main
contribution of this paper concerns the final registration phase. In
particular, we consider a least-squares formulation of the registration problem
(both with and without anchor constraints) and demonstrate how this otherwise
non-convex problem can be relaxed into a tractable convex program. We provide
some preliminary simulation results for large-scale SNL demonstrating that the
proposed registration algorithm (together with an accurate localization scheme)
offers a good tradeoff between run time and accuracy.Comment: 5 pages, 8 figures, 1 table. To appear in Proc. IEEE International
Conference on Acoustics, Speech, and Signal Processing, April 19-24, 201
Mutual Guidance and Residual Integration for Image Enhancement
Previous studies show the necessity of global and local adjustment for image
enhancement. However, existing convolutional neural networks (CNNs) and
transformer-based models face great challenges in balancing the computational
efficiency and effectiveness of global-local information usage. Especially,
existing methods typically adopt the global-to-local fusion mode, ignoring the
importance of bidirectional interactions. To address those issues, we propose a
novel mutual guidance network (MGN) to perform effective bidirectional
global-local information exchange while keeping a compact architecture. In our
design, we adopt a two-branch framework where one branch focuses more on
modeling global relations while the other is committed to processing local
information. Then, we develop an efficient attention-based mutual guidance
approach throughout our framework for bidirectional global-local interactions.
As a result, both the global and local branches can enjoy the merits of mutual
information aggregation. Besides, to further refine the results produced by our
MGN, we propose a novel residual integration scheme following the
divide-and-conquer philosophy. The extensive experiments demonstrate the
effectiveness of our proposed method, which achieves state-of-the-art
performance on several public image enhancement benchmarks.Comment: 17 pages, 15 figure
A Divide-and-Conquer Approach Towards Understanding Deep Networks
Deep neural networks have achieved tremendous success in various fields including medical image segmentation. However, they have long been criticized for being a black-box, in that interpretation, understanding and correcting architectures is difficult as there is no general theory for deep neural network design. Previously, precision learning was proposed to fuse deep architectures and traditional approaches. Deep networks constructed in this way benefit from the original known operator, have fewer parameters, and improved interpretability. However, they do not yield state-of-the-art performance in all applications. In this paper, we propose to analyze deep networks using known operators, by adopting a divide-and-conquer strategy to replace network components, whilst retaining networks performance. The task of retinal vessel segmentation is investigated for this purpose. We start with a high-performance U-Net and show by step-by-step conversion that we are able to divide the network into modules of known operators. The results indicate that a combination of a trainable guided filter and a trainable version of the Frangi filter yields a performance at the level of U-Net (AUC 0.974 vs. 0.972) with a tremendous reduction in parameters (111, 536 vs. 9, 575). In addition, the trained layers can be mapped back into their original algorithmic interpretation and analyzed using standard tools of signal processing
RSFNet: A White-Box Image Retouching Approach using Region-Specific Color Filters
Retouching images is an essential aspect of enhancing the visual appeal of
photos. Although users often share common aesthetic preferences, their
retouching methods may vary based on their individual preferences. Therefore,
there is a need for white-box approaches that produce satisfying results and
enable users to conveniently edit their images simultaneously. Recent white-box
retouching methods rely on cascaded global filters that provide image-level
filter arguments but cannot perform fine-grained retouching. In contrast,
colorists typically employ a divide-and-conquer approach, performing a series
of region-specific fine-grained enhancements when using traditional tools like
Davinci Resolve. We draw on this insight to develop a white-box framework for
photo retouching using parallel region-specific filters, called RSFNet. Our
model generates filter arguments (e.g., saturation, contrast, hue) and
attention maps of regions for each filter simultaneously. Instead of cascading
filters, RSFNet employs linear summations of filters, allowing for a more
diverse range of filter classes that can be trained more easily. Our
experiments demonstrate that RSFNet achieves state-of-the-art results, offering
satisfying aesthetic appeal and increased user convenience for editable
white-box retouching.Comment: Accepted by ICCV 202
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