有许多基于深卷卷神经网络（CNN）的图像恢复方法。但是，有关该主题的大多数文献都集中在网络体系结构和损失功能上，而对培训方法的详细介绍。因此，某些作品不容易重现，因为需要了解隐藏的培训技巧才能获得相同的结果。要具体说明培训数据集，很少有作品讨论了如何准备和订购培训图像补丁。此外，捕获新数据集以训练现实世界中的恢复网络需要高昂的成本。因此，我们认为有必要研究培训数据的准备和选择。在这方面，我们对训练贴片进行了分析，并探讨了不同斑块提取方法的后果。最终，我们提出了从给定训练图像中提取补丁的指南。

本文提出了图像恢复的新变异推理框架和一个卷积神经网络（CNN）结构，该结构可以解决所提出的框架所描述的恢复问题。较早的基于CNN的图像恢复方法主要集中在网络体系结构设计或培训策略上，具有非盲方案，其中已知或假定降解模型。为了更接近现实世界的应用程序，CNN还接受了整个数据集的盲目培训，包括各种降解。然而，给定有多样化的图像的高质量图像的条件分布太复杂了，无法通过单个CNN学习。因此，也有一些方法可以提供其他先验信息来培训CNN。与以前的方法不同，我们更多地专注于基于贝叶斯观点以及如何重新重新重构目标的恢复目标。具体而言，我们的方法放松了原始的后推理问题，以更好地管理子问题，因此表现得像分裂和互动方案。结果，与以前的框架相比，提出的框架提高了几个恢复问题的性能。具体而言，我们的方法在高斯denoising，现实世界中的降噪，盲图超级分辨率和JPEG压缩伪像减少方面提供了最先进的性能。

Discriminative model learning for image denoising has been recently attracting considerable attentions due to its favorable denoising performance. In this paper, we take one step forward by investigating the construction of feed-forward denoising convolutional neural networks (DnCNNs) to embrace the progress in very deep architecture, learning algorithm, and regularization method into image denoising. Specifically, residual learning and batch normalization are utilized to speed up the training process as well as boost the denoising performance. Different from the existing discriminative denoising models which usually train a specific model for additive white Gaussian noise (AWGN) at a certain noise level, our DnCNN model is able to handle Gaussian denoising with unknown noise level (i.e., blind Gaussian denoising). With the residual learning strategy, DnCNN implicitly removes the latent clean image in the hidden layers. This property motivates us to train a single DnCNN model to tackle with several general image denoising tasks such as Gaussian denoising, single image super-resolution and JPEG image deblocking. Our extensive experiments demonstrate that our DnCNN model can not only exhibit high effectiveness in several general image denoising tasks, but also be efficiently implemented by benefiting from GPU computing.

Recent research on super-resolution has progressed with the development of deep convolutional neural networks (DCNN). In particular, residual learning techniques exhibit improved performance. In this paper, we develop an enhanced deep super-resolution network (EDSR) with performance exceeding those of current state-of-the-art SR methods. The significant performance improvement of our model is due to optimization by removing unnecessary modules in conventional residual networks. The performance is further improved by expanding the model size while we stabilize the training procedure. We also propose a new multi-scale deep super-resolution system (MDSR) and training method, which can reconstruct high-resolution images of different upscaling factors in a single model. The proposed methods show superior performance over the state-of-the-art methods on benchmark datasets and prove its excellence by winning the NTIRE2017 Super-Resolution Challenge [26].

随着深度神经网络（DNN）的发展，已经提出了用于单图像超分辨率（SISR）的基于DNN的大量方法。然而，现有方法主要在均匀采样的LR-HR补丁对上培训DNN，这使得它们无法在图像中完全利用信息贴片。在本文中，我们提出了一种简单而有效的数据增强方法。我们首先设计启发式指标来评估每个补丁对的信息性重要性。为了降低所有补丁对的计算成本，我们进一步建议通过积分图像来优化我们的度量计算，从而实现大约两个数量级加速。训练补丁对根据他们的方法对我们的方法进行了抽样。广泛的实验表明，我们的采样增强可以一致地提高收敛性，并提高各种SISR架构的性能，包括跨不同缩放因子（X2，X3，X4）的EDSR，RCAN，RDN，SRCNN和ESPCN。代码可在https://github.com/littlepure2333/samplingaug上获得

我们介绍了一种新颖的可调图像恢复方法，该方法可实现多种模型的准确性，每个模型都针对不同级别的降解进行了优化，其参数数与单个模型的数量完全相同。可以优化我们的模型，以根据需要恒定数量的参数和各种图像恢复任务来恢复尽可能多的退化水平。现实世界数据集的实验表明，我们的方法实现了最先进的结果，从而在现有可调模型方面取得了denoising，dejpeg和超分辨率，从而使更平稳，更精确地拟合在更广泛的降级水平上。

We propose a deep learning method for single image superresolution (SR). Our method directly learns an end-to-end mapping between the low/high-resolution images. The mapping is represented as a deep convolutional neural network (CNN) [15] that takes the lowresolution image as the input and outputs the high-resolution one. We further show that traditional sparse-coding-based SR methods can also be viewed as a deep convolutional network. But unlike traditional methods that handle each component separately, our method jointly optimizes all layers. Our deep CNN has a lightweight structure, yet demonstrates state-of-the-art restoration quality, and achieves fast speed for practical on-line usage.

最近，基于深度学习的图像降级方法在测试数据上具有与训练集相同的测试数据的有希望的性能，在该数据中，已经学习了基于合成或收集的现实世界训练数据的各种denoising模型。但是，在处理真实世界的嘈杂图像时，Denoising的性能仍然受到限制。在本文中，我们提出了一种简单而有效的贝叶斯深集合（BDE）方法，用于真实世界图像denoising，其中可以融合使用各种训练数据设置进行预训练的几位代表性的深层Denoiser，以提高稳健性。 BDE的基础是，现实世界的图像噪声高度取决于信号依赖性，并且在现实世界中的嘈杂图像中的异质噪声可以由不同的Deoisiser分别处理。特别是，我们将受过良好训练的CBDNET，NBNET，HINET，UFORFORMER和GMSNET进入Denoiser池，并采用U-NET来预测Pixel的加权图以融合这些DeOisiser。引入了贝叶斯深度学习策略，而不是仅仅学习像素的加权地图，而是为了预测加权不确定性和加权图，可以通过该策略来建模预测差异，以改善现实世界中的嘈杂图像的鲁棒性。广泛的实验表明，可以通过融合现有的DINOISER而不是训练一个以昂贵的成本来训练一个大的Denoiser来更好地消除现实世界的噪音。在DND数据集上，我们的BDE实现了 +0.28〜dB PSNR的增益，而不是最先进的denoising方法。此外，我们注意到，在应用于现实世界嘈杂的图像时，基于不同高斯噪声水平的BDE Denoiser优于最先进的CBDNET。此外，我们的BDE可以扩展到其他图像恢复任务，并在基准数据集上获得 +0.30dB， +0.18dB和 +0.12dB PSNR的收益，以分别用于图像去除图像，图像降低和单个图像超级分辨率。

Neural Architecture Search (NAS) for automatically finding the optimal network architecture has shown some success with competitive performances in various computer vision tasks. However, NAS in general requires a tremendous amount of computations. Thus reducing computational cost has emerged as an important issue. Most of the attempts so far has been based on manual approaches, and often the architectures developed from such efforts dwell in the balance of the network optimality and the search cost. Additionally, recent NAS methods for image restoration generally do not consider dynamic operations that may transform dimensions of feature maps because of the dimensionality mismatch in tensor calculations. This can greatly limit NAS in its search for optimal network structure. To address these issues, we re-frame the optimal search problem by focusing at component block level. From previous work, it's been shown that an effective denoising block can be connected in series to further improve the network performance. By focusing at block level, the search space of reinforcement learning becomes significantly smaller and evaluation process can be conducted more rapidly. In addition, we integrate an innovative dimension matching modules for dealing with spatial and channel-wise mismatch that may occur in the optimal design search. This allows much flexibility in optimal network search within the cell block. With these modules, then we employ reinforcement learning in search of an optimal image denoising network at a module level. Computational efficiency of our proposed Denoising Prior Neural Architecture Search (DPNAS) was demonstrated by having it complete an optimal architecture search for an image restoration task by just one day with a single GPU.

盲图修复（IR）是计算机视觉中常见但充满挑战的问题。基于经典模型的方法和最新的深度学习（DL）方法代表了有关此问题的两种不同方法，每种方法都有自己的优点和缺点。在本文中，我们提出了一种新颖的盲图恢复方法，旨在整合它们的两种优势。具体而言，我们为盲IR构建了一个普通的贝叶斯生成模型，该模型明确描绘了降解过程。在此提出的模型中，PICEL的非I.I.D。高斯分布用于适合图像噪声。它的灵活性比简单的I.I.D。在大多数常规方法中采用的高斯或拉普拉斯分布，以处理图像降解中包含的更复杂的噪声类型。为了解决该模型，我们设计了一个变异推理算法，其中所有预期的后验分布都被参数化为深神经网络，以提高其模型能力。值得注意的是，这种推论算法诱导统一的框架共同处理退化估计和图像恢复的任务。此外，利用了前一种任务中估计的降解信息来指导后一种红外过程。对两项典型的盲型IR任务进行实验，即图像降解和超分辨率，表明所提出的方法比当前最新的方法实现了卓越的性能。

作为一个严重的问题，近年来已经广泛研究了单图超分辨率（SISR）。 SISR的主要任务是恢复由退化程序引起的信息损失。根据Nyquist抽样理论，降解会导致混叠效应，并使低分辨率（LR）图像的正确纹理很难恢复。实际上，自然图像中相邻斑块之间存在相关性和自相似性。本文考虑了自相似性，并提出了一个分层图像超分辨率网络（HSRNET）来抑制混叠的影响。我们从优化的角度考虑SISR问题，并根据半季节分裂（HQS）方法提出了迭代解决方案模式。为了先验探索本地图像的质地，我们设计了一个分层探索块（HEB）并进行性增加了接受场。此外，设计多级空间注意力（MSA）是为了获得相邻特征的关系并增强了高频信息，这是视觉体验的关键作用。实验结果表明，与其他作品相比，HSRNET实现了更好的定量和视觉性能，并更有效地释放了别名。

Single image super-resolution is the task of inferring a high-resolution image from a single low-resolution input. Traditionally, the performance of algorithms for this task is measured using pixel-wise reconstruction measures such as peak signal-to-noise ratio (PSNR) which have been shown to correlate poorly with the human perception of image quality. As a result, algorithms minimizing these metrics tend to produce over-smoothed images that lack highfrequency textures and do not look natural despite yielding high PSNR values.We propose a novel application of automated texture synthesis in combination with a perceptual loss focusing on creating realistic textures rather than optimizing for a pixelaccurate reproduction of ground truth images during training. By using feed-forward fully convolutional neural networks in an adversarial training setting, we achieve a significant boost in image quality at high magnification ratios. Extensive experiments on a number of datasets show the effectiveness of our approach, yielding state-of-the-art results in both quantitative and qualitative benchmarks.

Convolutional Neural Network (CNN)-based image super-resolution (SR) has exhibited impressive success on known degraded low-resolution (LR) images. However, this type of approach is hard to hold its performance in practical scenarios when the degradation process is unknown. Despite existing blind SR methods proposed to solve this problem using blur kernel estimation, the perceptual quality and reconstruction accuracy are still unsatisfactory. In this paper, we analyze the degradation of a high-resolution (HR) image from image intrinsic components according to a degradation-based formulation model. We propose a components decomposition and co-optimization network (CDCN) for blind SR. Firstly, CDCN decomposes the input LR image into structure and detail components in feature space. Then, the mutual collaboration block (MCB) is presented to exploit the relationship between both two components. In this way, the detail component can provide informative features to enrich the structural context and the structure component can carry structural context for better detail revealing via a mutual complementary manner. After that, we present a degradation-driven learning strategy to jointly supervise the HR image detail and structure restoration process. Finally, a multi-scale fusion module followed by an upsampling layer is designed to fuse the structure and detail features and perform SR reconstruction. Empowered by such degradation-based components decomposition, collaboration, and mutual optimization, we can bridge the correlation between component learning and degradation modelling for blind SR, thereby producing SR results with more accurate textures. Extensive experiments on both synthetic SR datasets and real-world images show that the proposed method achieves the state-of-the-art performance compared to existing methods.

Image restoration tasks demand a complex balance between spatial details and high-level contextualized information while recovering images. In this paper, we propose a novel synergistic design that can optimally balance these competing goals. Our main proposal is a multi-stage architecture, that progressively learns restoration functions for the degraded inputs, thereby breaking down the overall recovery process into more manageable steps. Specifically, our model first learns the contextualized features using encoder-decoder architectures and later combines them with a high-resolution branch that retains local information. At each stage, we introduce a novel per-pixel adaptive design that leverages in-situ supervised attention to reweight the local features. A key ingredient in such a multi-stage architecture is the information exchange between different stages. To this end, we propose a twofaceted approach where the information is not only exchanged sequentially from early to late stages, but lateral connections between feature processing blocks also exist to avoid any loss of information. The resulting tightly interlinked multi-stage architecture, named as MPRNet, delivers strong performance gains on ten datasets across a range of tasks including image deraining, deblurring, and denoising. The source code and pre-trained models are available at https://github.com/swz30/MPRNet.

压缩在通过限制系统（例如流媒体服务，虚拟现实或视频游戏）等系统的有效传输和存储图像和视频中起着重要作用。但是，不可避免地会导致伪影和原始信息的丢失，这可能会严重降低视觉质量。由于这些原因，压缩图像的质量增强已成为流行的研究主题。尽管大多数最先进的图像恢复方法基于卷积神经网络，但基于Swinir等其他基于变压器的方法在这些任务上表现出令人印象深刻的性能。在本文中，我们探索了新型的Swin Transformer V2，以改善图像超分辨率的Swinir，尤其是压缩输入方案。使用这种方法，我们可以解决训练变压器视觉模型中的主要问题，例如训练不稳定性，预训练和微调之间的分辨率差距以及数据饥饿。我们对三个代表性任务进行实验：JPEG压缩伪像去除，图像超分辨率（经典和轻巧）以及压缩的图像超分辨率。实验结果表明，我们的方法SWIN2SR可以改善SWINIR的训练收敛性和性能，并且是“ AIM 2022挑战压缩图像和视频的超分辨率”的前5个解决方案。

对比学习在各种高级任务中取得了显着的成功，但是为低级任务提出了较少的方法。采用VANILLA对比学习技术采用直接为低级视觉任务提出的VANILLA对比度学习技术，因为所获得的全局视觉表现不足以用于需要丰富的纹理和上下文信息的低级任务。在本文中，我们提出了一种用于单图像超分辨率（SISR）的新型对比学习框架。我们从两个视角调查基于对比的学习的SISR：样品施工和特征嵌入。现有方法提出了一些天真的样本施工方法（例如，考虑到作为负样本的低质量输入以及作为正样品的地面真理），并且它们采用了先前的模型（例如，预先训练的VGG模型）来获得该特征嵌入而不是探索任务友好的。为此，我们向SISR提出了一个实用的对比学习框架，涉及在频率空间中产生许多信息丰富的正负样本。我们不是利用其他预先训练的网络，我们设计了一种从鉴别器网络继承的简单但有效的嵌入网络，并且可以用主SR网络迭代优化，使其成为任务最通报。最后，我们对我们的方法进行了广泛的实验评估，与基准方法相比，在目前的最先进的SISR方法中显示出高达0.21 dB的显着增益。

Recently, very deep convolutional neural networks (CNNs) have been attracting considerable attention in image restoration. However, as the depth grows, the long-term dependency problem is rarely realized for these very deep models, which results in the prior states/layers having little influence on the subsequent ones. Motivated by the fact that human thoughts have persistency, we propose a very deep persistent memory network (MemNet) that introduces a memory block, consisting of a recursive unit and a gate unit, to explicitly mine persistent memory through an adaptive learning process. The recursive unit learns multi-level representations of the current state under different receptive fields. The representations and the outputs from the previous memory blocks are concatenated and sent to the gate unit, which adaptively controls how much of the previous states should be reserved, and decides how much of the current state should be stored. We apply MemNet to three image restoration tasks, i.e., image denosing, superresolution and JPEG deblocking. Comprehensive experiments demonstrate the necessity of the MemNet and its unanimous superiority on all three tasks over the state of the arts. Code is available at https://github.com/ tyshiwo/MemNet.

由于卷积神经网络（CNNS）在从大规模数据中进行了学习的可概括图像前沿执行井，因此这些模型已被广泛地应用于图像恢复和相关任务。最近，另一类神经架构，变形金刚表现出对自然语言和高级视觉任务的显着性能。虽然变压器模型减轻了CNNS的缺点（即，有限的接收领域并对输入内容而无关），但其计算复杂性以空间分辨率二次大转，因此可以对涉及高分辨率图像的大多数图像恢复任务应用得不可行。在这项工作中，我们通过在构建块（多头关注和前锋网络）中进行多个关键设计，提出了一种有效的变压器模型，使得它可以捕获远程像素相互作用，同时仍然适用于大图像。我们的模型，命名恢复变压器（RESTORMER），实现了最先进的结果，导致几种图像恢复任务，包括图像派生，单图像运动脱棕，散焦去纹（单图像和双像素数据）和图像去噪（高斯灰度/颜色去噪，真实的图像去噪）。源代码和预先训练的型号可在https://github.com/swz30/restormer上获得。

最近的作品表明，卷积神经网络（CNN）架构具有朝向较低频率的光谱偏压，这已经针对在之前（DIP）框架中的深度图像中的各种图像恢复任务而被利用。归纳偏置的益处网络施加在DIP框架中取决于架构。因此，研究人员研究了如何自动化搜索来确定最佳性能的模型。然而，常见的神经结构搜索（NAS）技术是资源和时间密集的。此外，最佳性能的模型是针对整个图像的整个数据集而不是为每个图像独立地确定，这将是非常昂贵的。在这项工作中，我们首先表明DIP框架中的最佳神经结构是依赖于图像的。然后利用这种洞察力，我们提出了一种特定于DIP框架的图像特定的NAS策略，其需要比典型的NAS方法大得多，有效地实现特定于图像的NA。对于给定的图像，噪声被馈送到大量未训练的CNN，并且它们的输出的功率谱密度（PSD）与使用各种度量的损坏图像进行比较。基于此，选择并培训了一个小型的图像特定架构，以重建损坏的图像。在这种队列中，选择重建最接近重建图像的平均值的模型作为最终模型。我们向拟议的战略证明（1）证明其在NAS数据集上的表现效果，该数据集包括来自特定搜索空间（2）的500多种模型，在特定的搜索空间（2）上进行了广泛的图像去噪，染色和超级分辨率任务。我们的实验表明，图像特定度量可以将搜索空间减少到小型模型队列，其中最佳模型优于电流NAS用于图像恢复的方法。

近年来，压缩图像超分辨率已引起了极大的关注，其中图像被压缩伪像和低分辨率伪影降解。由于复杂的杂化扭曲变形，因此很难通过简单的超分辨率和压缩伪像消除掉的简单合作来恢复扭曲的图像。在本文中，我们向前迈出了一步，提出了层次的SWIN变压器（HST）网络，以恢复低分辨率压缩图像，该图像共同捕获分层特征表示并分别用SWIN Transformer增强每个尺度表示。此外，我们发现具有超分辨率（SR）任务的预处理对于压缩图像超分辨率至关重要。为了探索不同的SR预审查的影响，我们将常用的SR任务（例如，比科比奇和不同的实际超分辨率仿真）作为我们的预处理任务，并揭示了SR在压缩的图像超分辨率中起不可替代的作用。随着HST和预训练的合作，我们的HST在AIM 2022挑战中获得了低质量压缩图像超分辨率轨道的第五名，PSNR为23.51db。广泛的实验和消融研究已经验证了我们提出的方法的有效性。