8,667 research outputs found
Real-time Controllable Denoising for Image and Video
Controllable image denoising aims to generate clean samples with human
perceptual priors and balance sharpness and smoothness. In traditional
filter-based denoising methods, this can be easily achieved by adjusting the
filtering strength. However, for NN (Neural Network)-based models, adjusting
the final denoising strength requires performing network inference each time,
making it almost impossible for real-time user interaction. In this paper, we
introduce Real-time Controllable Denoising (RCD), the first deep image and
video denoising pipeline that provides a fully controllable user interface to
edit arbitrary denoising levels in real-time with only one-time network
inference. Unlike existing controllable denoising methods that require multiple
denoisers and training stages, RCD replaces the last output layer (which
usually outputs a single noise map) of an existing CNN-based model with a
lightweight module that outputs multiple noise maps. We propose a novel Noise
Decorrelation process to enforce the orthogonality of the noise feature maps,
allowing arbitrary noise level control through noise map interpolation. This
process is network-free and does not require network inference. Our experiments
show that RCD can enable real-time editable image and video denoising for
various existing heavy-weight models without sacrificing their original
performance.Comment: CVPR 202
Enhanced CNN for image denoising
Owing to flexible architectures of deep convolutional neural networks (CNNs),
CNNs are successfully used for image denoising. However, they suffer from the
following drawbacks: (i) deep network architecture is very difficult to train.
(ii) Deeper networks face the challenge of performance saturation. In this
study, the authors propose a novel method called enhanced convolutional neural
denoising network (ECNDNet). Specifically, they use residual learning and batch
normalisation techniques to address the problem of training difficulties and
accelerate the convergence of the network. In addition, dilated convolutions
are used in the proposed network to enlarge the context information and reduce
the computational cost. Extensive experiments demonstrate that the ECNDNet
outperforms the state-of-the-art methods for image denoising.Comment: CAAI Transactions on Intelligence Technology[J], 201
Image Denoising with Graph-Convolutional Neural Networks
Recovering an image from a noisy observation is a key problem in signal
processing. Recently, it has been shown that data-driven approaches employing
convolutional neural networks can outperform classical model-based techniques,
because they can capture more powerful and discriminative features. However,
since these methods are based on convolutional operations, they are only
capable of exploiting local similarities without taking into account non-local
self-similarities. In this paper we propose a convolutional neural network that
employs graph-convolutional layers in order to exploit both local and non-local
similarities. The graph-convolutional layers dynamically construct
neighborhoods in the feature space to detect latent correlations in the feature
maps produced by the hidden layers. The experimental results show that the
proposed architecture outperforms classical convolutional neural networks for
the denoising task.Comment: IEEE International Conference on Image Processing (ICIP) 201
Neural Nearest Neighbors Networks
Non-local methods exploiting the self-similarity of natural signals have been
well studied, for example in image analysis and restoration. Existing
approaches, however, rely on k-nearest neighbors (KNN) matching in a fixed
feature space. The main hurdle in optimizing this feature space w.r.t.
application performance is the non-differentiability of the KNN selection rule.
To overcome this, we propose a continuous deterministic relaxation of KNN
selection that maintains differentiability w.r.t. pairwise distances, but
retains the original KNN as the limit of a temperature parameter approaching
zero. To exploit our relaxation, we propose the neural nearest neighbors block
(N3 block), a novel non-local processing layer that leverages the principle of
self-similarity and can be used as building block in modern neural network
architectures. We show its effectiveness for the set reasoning task of
correspondence classification as well as for image restoration, including image
denoising and single image super-resolution, where we outperform strong
convolutional neural network (CNN) baselines and recent non-local models that
rely on KNN selection in hand-chosen features spaces.Comment: to appear at NIPS*2018, code available at
https://github.com/visinf/n3net
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