163 research outputs found
Deep Plug-and-Play Prior for Hyperspectral Image Restoration
Deep-learning-based hyperspectral image (HSI) restoration methods have gained
great popularity for their remarkable performance but often demand expensive
network retraining whenever the specifics of task changes. In this paper, we
propose to restore HSIs in a unified approach with an effective plug-and-play
method, which can jointly retain the flexibility of optimization-based methods
and utilize the powerful representation capability of deep neural networks.
Specifically, we first develop a new deep HSI denoiser leveraging gated
recurrent convolution units, short- and long-term skip connections, and an
augmented noise level map to better exploit the abundant spatio-spectral
information within HSIs. It, therefore, leads to the state-of-the-art
performance on HSI denoising under both Gaussian and complex noise settings.
Then, the proposed denoiser is inserted into the plug-and-play framework as a
powerful implicit HSI prior to tackle various HSI restoration tasks. Through
extensive experiments on HSI super-resolution, compressed sensing, and
inpainting, we demonstrate that our approach often achieves superior
performance, which is competitive with or even better than the state-of-the-art
on each task, via a single model without any task-specific training.Comment: code at https://github.com/Zeqiang-Lai/DPHSI
Instance Segmentation in the Dark
Existing instance segmentation techniques are primarily tailored for
high-visibility inputs, but their performance significantly deteriorates in
extremely low-light environments. In this work, we take a deep look at instance
segmentation in the dark and introduce several techniques that substantially
boost the low-light inference accuracy. The proposed method is motivated by the
observation that noise in low-light images introduces high-frequency
disturbances to the feature maps of neural networks, thereby significantly
degrading performance. To suppress this ``feature noise", we propose a novel
learning method that relies on an adaptive weighted downsampling layer, a
smooth-oriented convolutional block, and disturbance suppression learning.
These components effectively reduce feature noise during downsampling and
convolution operations, enabling the model to learn disturbance-invariant
features. Furthermore, we discover that high-bit-depth RAW images can better
preserve richer scene information in low-light conditions compared to typical
camera sRGB outputs, thus supporting the use of RAW-input algorithms. Our
analysis indicates that high bit-depth can be critical for low-light instance
segmentation. To mitigate the scarcity of annotated RAW datasets, we leverage a
low-light RAW synthetic pipeline to generate realistic low-light data. In
addition, to facilitate further research in this direction, we capture a
real-world low-light instance segmentation dataset comprising over two thousand
paired low/normal-light images with instance-level pixel-wise annotations.
Remarkably, without any image preprocessing, we achieve satisfactory
performance on instance segmentation in very low light (4~\% AP higher than
state-of-the-art competitors), meanwhile opening new opportunities for future
research.Comment: Accepted by International Journal of Computer Vision (IJCV) 202
Spatially Varying Nanophotonic Neural Networks
The explosive growth of computation and energy cost of artificial
intelligence has spurred strong interests in new computing modalities as
potential alternatives to conventional electronic processors. Photonic
processors that execute operations using photons instead of electrons, have
promised to enable optical neural networks with ultra-low latency and power
consumption. However, existing optical neural networks, limited by the
underlying network designs, have achieved image recognition accuracy much lower
than state-of-the-art electronic neural networks. In this work, we close this
gap by introducing a large-kernel spatially-varying convolutional neural
network learned via low-dimensional reparameterization techniques. We
experimentally instantiate the network with a flat meta-optical system that
encompasses an array of nanophotonic structures designed to induce
angle-dependent responses. Combined with an extremely lightweight electronic
backend with approximately 2K parameters we demonstrate a nanophotonic neural
network reaches 73.80\% blind test classification accuracy on CIFAR-10 dataset,
and, as such, the first time, an optical neural network outperforms the first
modern digital neural network -- AlexNet (72.64\%) with 57M parameters,
bringing optical neural network into modern deep learning era
Learning to Fuse Monocular and Multi-view Cues for Multi-frame Depth Estimation in Dynamic Scenes
Multi-frame depth estimation generally achieves high accuracy relying on the
multi-view geometric consistency. When applied in dynamic scenes, e.g.,
autonomous driving, this consistency is usually violated in the dynamic areas,
leading to corrupted estimations. Many multi-frame methods handle dynamic areas
by identifying them with explicit masks and compensating the multi-view cues
with monocular cues represented as local monocular depth or features. The
improvements are limited due to the uncontrolled quality of the masks and the
underutilized benefits of the fusion of the two types of cues. In this paper,
we propose a novel method to learn to fuse the multi-view and monocular cues
encoded as volumes without needing the heuristically crafted masks. As unveiled
in our analyses, the multi-view cues capture more accurate geometric
information in static areas, and the monocular cues capture more useful
contexts in dynamic areas. To let the geometric perception learned from
multi-view cues in static areas propagate to the monocular representation in
dynamic areas and let monocular cues enhance the representation of multi-view
cost volume, we propose a cross-cue fusion (CCF) module, which includes the
cross-cue attention (CCA) to encode the spatially non-local relative
intra-relations from each source to enhance the representation of the other.
Experiments on real-world datasets prove the significant effectiveness and
generalization ability of the proposed method.Comment: Accepted by CVPR 2023. Code and models are available at:
https://github.com/ruili3/dynamic-multiframe-dept
Seasonal Variations in Hydrological Influences on Gravity Measurements Using gPhones
Hydrological influences on a local gravity field may reach amplitudes on the order of 10 microgals. Since 2007, fifteen Microg LaCoste gPhones have been successively installed in gravity stations in China. The outputs from gPhones include ten data channels with second sampling such as raw gravity, corrected gravity, long level data and cross level data, ambient and sensor temperature, ambient and sensor pressure, and others. In this study, we select six stations in northwest China (GaoTai, LaSa, LanZhou, ShiQuanHe, WuShi, XiAn) and one station in the northeast (HaiLaEr). We have modeled the major tides (earth solid tide, ocean tide and pole tide), corrected for atmospheric loading effects using local measurements, fitted instrumental drift using segmental fitting based on the distinct characteristics of gravimeter drift, and ultimately obtained the monthly residual gravity with amplitudes of 10 ~ 20 microgals. We find that the results obtained by the gravimeter for those stations with stable conditions and no large disturbances are obviously correlated with hydrologic loading as modeled by the Global Land Data Assimilation System and Climate Prediction Center. We also notice that at some stations there are obvious phase lags with a period of three months or more between the residual gravity and the influence of hydrological loading. These large discrepancies may be associated with local hydrologic effects, local topography or some other complex tectonic movement and geodynamical mechanism, which were not considered in this paper
Research on multi-layer network routing selection strategy based on cooperative evolutionary game in IoT environment
As a new technology and application mode, the Internet of Things has an important impact on social life and economic development. In recent years, low-cost optimization of network transmission to solve the congestion problem of multi-layer communication networks has become one of the research hotspots. In this paper, a multi-dimensional communication data transmission model based on a multi-layer network is proposed. It then uses cooperative evolutionary game theory to calculate revenue, update weights, and adapt neighbors. Finally, the attention mechanism is dynamically introduced to share the weights of the multi-layer network, and the multi-dimensional communication propagation and routing strategies in the Internet of Things are studied and analyzed. The experimental results show that the model proposed in this paper has higher game revenue and application value than traditional single-layer network game theory. In particular, the indicators of cooperation rate, stable state, and maximum cooperation rate are better than the latter. The research results of this paper have important reference value for solving the problems of cooperation dilemma, social stickiness, and synergy in multi-layer networks
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