单个图像超分辨率（SISR）是一个非常活跃的研究领域。本文通过使用带有双鉴别器的GaN的方法来解决SISR，并将其与注意机制合并。实验结果表明，与其他传统方法相比，GDCA可以产生更尖锐和高令人愉悦的图像。

盲目图像超分辨率（SR）是CV的长期任务，旨在恢复患有未知和复杂扭曲的低分辨率图像。最近的工作主要集中在采用更复杂的退化模型来模拟真实世界的降级。由此产生的模型在感知损失和产量感知令人信服的结果取得了突破性。然而，电流生成的对抗性网络结构所带来的限制仍然是显着的：处理像素同样地导致图像的结构特征的无知，并且导致性能缺点，例如扭曲线和背景过度锐化或模糊。在本文中，我们提出了A-ESRAN，用于盲人SR任务的GAN模型，其特色是基于U-NET的U-NET的多尺度鉴别器，可以与其他发电机无缝集成。据我们所知，这是第一项介绍U-Net结构作为GaN解决盲人问题的鉴别者的工作。本文还给出了对模型的多规模注意力突破的机制的解释。通过对现有作品的比较实验，我们的模型在非参考自然图像质量评估员度量上提出了最先进的水平性能。我们的消融研究表明，利用我们的鉴别器，基于RRDB的发电机可以利用多种尺度中图像的结构特征，因此与先前作品相比，更加感知地产生了感知的高分辨率图像。

Despite the breakthroughs in accuracy and speed of single image super-resolution using faster and deeper convolutional neural networks, one central problem remains largely unsolved: how do we recover the finer texture details when we super-resolve at large upscaling factors? The behavior of optimization-based super-resolution methods is principally driven by the choice of the objective function. Recent work has largely focused on minimizing the mean squared reconstruction error. The resulting estimates have high peak signal-to-noise ratios, but they are often lacking high-frequency details and are perceptually unsatisfying in the sense that they fail to match the fidelity expected at the higher resolution. In this paper, we present SRGAN, a generative adversarial network (GAN) for image superresolution (SR). To our knowledge, it is the first framework capable of inferring photo-realistic natural images for 4× upscaling factors. To achieve this, we propose a perceptual loss function which consists of an adversarial loss and a content loss. The adversarial loss pushes our solution to the natural image manifold using a discriminator network that is trained to differentiate between the super-resolved images and original photo-realistic images. In addition, we use a content loss motivated by perceptual similarity instead of similarity in pixel space. Our deep residual network is able to recover photo-realistic textures from heavily downsampled images on public benchmarks. An extensive mean-opinion-score (MOS) test shows hugely significant gains in perceptual quality using SRGAN. The MOS scores obtained with SRGAN are closer to those of the original high-resolution images than to those obtained with any state-of-the-art method.

The Super-Resolution Generative Adversarial Network (SR-GAN) [1] is a seminal work that is capable of generating realistic textures during single image super-resolution. However, the hallucinated details are often accompanied with unpleasant artifacts. To further enhance the visual quality, we thoroughly study three key components of SRGANnetwork architecture, adversarial loss and perceptual loss, and improve each of them to derive an Enhanced SRGAN (ESRGAN). In particular, we introduce the Residual-in-Residual Dense Block (RRDB) without batch normalization as the basic network building unit. Moreover, we borrow the idea from relativistic GAN [2] to let the discriminator predict relative realness instead of the absolute value. Finally, we improve the perceptual loss by using the features before activation, which could provide stronger supervision for brightness consistency and texture recovery. Benefiting from these improvements, the proposed ESRGAN achieves consistently better visual quality with more realistic and natural textures than SRGAN and won the first place in the PIRM2018-SR Challenge 1 [3]. The code is available at https://github.com/xinntao/ESRGAN.

在实际应用中，识别网络的性能通常在应用于超分辨率图像时减少。在本文中，我们提出了一种基于特征的识别网络与GaN（FGAN）相结合。我们的网络通过提取从SR图像中识别的更多功能来提高识别准确性。在实验中，我们使用三种不同的超分辨率算法构建三个数据集，我们的网络将识别精度增加超过6％，与Reanet50和DenSenet121相比比较。

Because of the necessity to obtain high-quality images with minimal radiation doses, such as in low-field magnetic resonance imaging, super-resolution reconstruction in medical imaging has become more popular (MRI). However, due to the complexity and high aesthetic requirements of medical imaging, image super-resolution reconstruction remains a difficult challenge. In this paper, we offer a deep learning-based strategy for reconstructing medical images from low resolutions utilizing Transformer and Generative Adversarial Networks (T-GAN). The integrated system can extract more precise texture information and focus more on important locations through global image matching after successfully inserting Transformer into the generative adversarial network for picture reconstruction. Furthermore, we weighted the combination of content loss, adversarial loss, and adversarial feature loss as the final multi-task loss function during the training of our proposed model T-GAN. In comparison to established measures like PSNR and SSIM, our suggested T-GAN achieves optimal performance and recovers more texture features in super-resolution reconstruction of MRI scanned images of the knees and belly.

可以使用超分辨率方法改善医学图像的空间分辨率。实际增强的超级分辨率生成对抗网络（Real-Esrgan）是最近用于产生较高分辨率图像的最新有效方法之一，给定较低分辨率的输入图像。在本文中，我们应用这种方法来增强2D MR图像的空间分辨率。在我们提出的方法中，我们稍微修改了从脑肿瘤分割挑战（BRATS）2018数据集中训练2D磁共振图像（MRI）的结构。通过计算SSIM（结构相似性指数量度），NRMSE（归一化根平方误），MAE（平均绝对误差）和VIF（视觉信息保真度）值，通过计算SSIM（结构相似性指数量度）进行定性和定量验证。

近年来，使用基于深入学习的架构的状态，在图像超分辨率的任务中有几个进步。先前发布的许多基于超分辨率的技术，需要高端和顶部的图形处理单元（GPU）来执行图像超分辨率。随着深度学习方法的进步越来越大，神经网络已经变得越来越多地计算饥饿。我们返回了一步，并专注于创建实时有效的解决方案。我们提出了一种在其内存足迹方面更快更小的架构。所提出的架构使用深度明智的可分离卷积来提取特征，并且它与其他超分辨率的GAN（生成对抗网络）进行接受，同时保持实时推断和低存储器占用。即使在带宽条件不佳，实时超分辨率也能够流式传输高分辨率介质内容。在维持准确性和延迟之间的有效权衡之间，我们能够生产可比较的性能模型，该性能模型是超分辨率GAN的大小的一个 - 八（1/8），并且计算的速度比超分辨率的GAN快74倍。

单个图像超分辨率（SISR）是一个不良问题，旨在获得从低分辨率（LR）输入的高分辨率（HR）输出，在此期间应该添加额外的高频信息以改善感知质量。现有的SISR工作主要通过最小化平均平方重建误差来在空间域中运行。尽管高峰峰值信噪比（PSNR）结果，但难以确定模型是否正确地添加所需的高频细节。提出了一些基于基于残余的结构，以指导模型暗示高频率特征。然而，由于空间域度量的解释是有限的，如何验证这些人为细节的保真度仍然是一个问题。在本文中，我们提出了频率域视角来的直观管道，解决了这个问题。由现有频域的工作启发，我们将图像转换为离散余弦变换（DCT）块，然后改革它们以获取DCT功能映射，它用作我们模型的输入和目标。设计了专门的管道，我们进一步提出了符合频域任务的性质的频率损失功能。我们的SISR方法在频域中可以明确地学习高频信息，为SR图像提供保真度和良好的感知质量。我们进一步观察到我们的模型可以与其他空间超分辨率模型合并，以提高原始SR输出的质量。

Informative features play a crucial role in the single image super-resolution task. Channel attention has been demonstrated to be effective for preserving information-rich features in each layer. However, channel attention treats each convolution layer as a separate process that misses the correlation among different layers. To address this problem, we propose a new holistic attention network (HAN), which consists of a layer attention module (LAM) and a channel-spatial attention module (CSAM), to model the holistic interdependencies among layers, channels, and positions. Specifically, the proposed LAM adaptively emphasizes hierarchical features by considering correlations among layers. Meanwhile, CSAM learns the confidence at all the positions of each channel to selectively capture more informative features. Extensive experiments demonstrate that the proposed HAN performs favorably against the state-ofthe-art single image super-resolution approaches.

面部超分辨率方法的性能依赖于它们有效地收回面部结构和突出特征的能力。尽管卷积神经网络和基于生成的对抗网络的方法在面对幻觉任务中提供令人印象深刻的性能，但使用与低分辨率图像相关的属性来提高性能的能力是不令人满意的。在本文中，我们提出了一种属性引导的注意力发生抗体网络，该受体对抗网络采用新的属性引导的注意力（AGA）模块来识别和聚焦图像中各种面部特征的生成过程。堆叠多个AGA模块可以恢复高电平的高级面部结构。我们设计鉴别者来学习利用高分辨率图像与其相应的面部属性注释之间关系的鉴别特征。然后，我们探索基于U-Net的架构来改进现有预测并综合进一步的面部细节。跨越几个指标的广泛实验表明，我们的AGA-GaN和Aga-GaN + U-Net框架优于其他几种最先进的幻觉的方法。我们还演示了我们的方法的可行性，当每个属性描述符未知并因此建立其在真实情景中的应用程序时。

成功地应用生成的对抗性网络（GaN）以研究感知单个图像超级度（SISR）。然而，GaN经常倾向于产生具有高频率细节的图像与真实的细节不一致。灵感来自传统细节增强算法，我们提出了一种新的先前知识，先前的细节，帮助GaN减轻这个问题并恢复更现实的细节。所提出的方法名为DSRAN，包括良好设计的详细提取算法，用于捕获图像中最重要的高频信息。然后，两种鉴别器分别用于在图像域和细节域修复上进行监督。 DSRGAN通过细节增强方式将恢复的细节合并到最终输出中。 DSRGAN的特殊设计从基于模型的常规算法和数据驱动的深度学习网络中获得了优势。实验结果表明，DSRGAN在感知度量上表现出最先进的SISR方法，并同时达到保真度量的可比结果。在DSRGAN之后，将其他传统的图像处理算法结合到深度学习网络中，以形成基于模型的深SISR。

现实的高光谱图像（HSI）超分辨率（SR）技术旨在从其低分辨率（LR）对应物中产生具有更高光谱和空间忠诚的高分辨率（HR）HSI。生成的对抗网络（GAN）已被证明是图像超分辨率的有效深入学习框架。然而，现有GaN的模型的优化过程经常存在模式崩溃问题，导致光谱间不变重建容量有限。这可能导致所生成的HSI上的光谱空间失真，尤其是具有大的升级因子。为了缓解模式崩溃的问题，这项工作提出了一种与潜在编码器（Le-GaN）耦合的新型GaN模型，其可以将产生的光谱空间特征从图像空间映射到潜在空间并产生耦合组件正规化生成的样本。基本上，我们将HSI视为嵌入在潜在空间中的高维歧管。因此，GaN模型的优化被转换为学习潜在空间中的高分辨率HSI样本的分布的问题，使得产生的超分辨率HSI的分布更接近其原始高分辨率对应物的那些。我们对超级分辨率的模型性能进行了实验评估及其在缓解模式崩溃中的能力。基于具有不同传感器（即Aviris和UHD-185）的两种实际HSI数据集进行了测试和验证，用于各种升高因素并增加噪声水平，并与最先进的超分辨率模型相比（即Hyconet，LTTR，Bagan，SR-GaN，Wgan）。

Face super-resolution is a domain-specific image super-resolution, which aims to generate High-Resolution (HR) face images from their Low-Resolution (LR) counterparts. In this paper, we propose a novel face super-resolution method, namely Semantic Encoder guided Generative Adversarial Face Ultra-Resolution Network (SEGA-FURN) to ultra-resolve an unaligned tiny LR face image to its HR counterpart with multiple ultra-upscaling factors (e.g., 4x and 8x). The proposed network is composed of a novel semantic encoder that has the ability to capture the embedded semantics to guide adversarial learning and a novel generator that uses a hierarchical architecture named Residual in Internal Dense Block (RIDB). Moreover, we propose a joint discriminator which discriminates both image data and embedded semantics. The joint discriminator learns the joint probability distribution of the image space and latent space. We also use a Relativistic average Least Squares loss (RaLS) as the adversarial loss to alleviate the gradient vanishing problem and enhance the stability of the training procedure. Extensive experiments on large face datasets have proved that the proposed method can achieve superior super-resolution results and significantly outperform other state-of-the-art methods in both qualitative and quantitative comparisons.

图像超分辨率（SR）是重要的图像处理方法之一，可改善计算机视野领域的图像分辨率。在过去的二十年中，在超级分辨率领域取得了重大进展，尤其是通过使用深度学习方法。这项调查是为了在深度学习的角度进行详细的调查，对单像超分辨率的最新进展进行详细的调查，同时还将告知图像超分辨率的初始经典方法。该调查将图像SR方法分类为四个类别，即经典方法，基于学习的方法，无监督学习的方法和特定领域的SR方法。我们还介绍了SR的问题，以提供有关图像质量指标，可用参考数据集和SR挑战的直觉。使用参考数据集评估基于深度学习的方法。一些审查的最先进的图像SR方法包括增强的深SR网络（EDSR），周期循环gan（Cincgan），多尺度残留网络（MSRN），Meta残留密度网络（META-RDN） ，反复反射网络（RBPN），二阶注意网络（SAN），SR反馈网络（SRFBN）和基于小波的残留注意网络（WRAN）。最后，这项调查以研究人员将解决SR的未来方向和趋势和开放问题的未来方向和趋势。

Despite that convolutional neural networks (CNN) have recently demonstrated high-quality reconstruction for single-image super-resolution (SR), recovering natural and realistic texture remains a challenging problem. In this paper, we show that it is possible to recover textures faithful to semantic classes. In particular, we only need to modulate features of a few intermediate layers in a single network conditioned on semantic segmentation probability maps. This is made possible through a novel Spatial Feature Transform (SFT) layer that generates affine transformation parameters for spatial-wise feature modulation. SFT layers can be trained end-to-end together with the SR network using the same loss function. During testing, it accepts an input image of arbitrary size and generates a high-resolution image with just a single forward pass conditioned on the categorical priors. Our final results show that an SR network equipped with SFT can generate more realistic and visually pleasing textures in comparison to state-of-the-art SRGAN [27] and EnhanceNet [38].

Convolutional neural network (CNN) depth is of crucial importance for image super-resolution (SR). However, we observe that deeper networks for image SR are more difficult to train. The lowresolution inputs and features contain abundant low-frequency information, which is treated equally across channels, hence hindering the representational ability of CNNs. To solve these problems, we propose the very deep residual channel attention networks (RCAN). Specifically, we propose a residual in residual (RIR) structure to form very deep network, which consists of several residual groups with long skip connections. Each residual group contains some residual blocks with short skip connections. Meanwhile, RIR allows abundant low-frequency information to be bypassed through multiple skip connections, making the main network focus on learning high-frequency information. Furthermore, we propose a channel attention mechanism to adaptively rescale channel-wise features by considering interdependencies among channels. Extensive experiments show that our RCAN achieves better accuracy and visual improvements against state-of-the-art methods.

Deep Convolutional Neural Networks (DCNNs) have exhibited impressive performance on image super-resolution tasks. However, these deep learning-based super-resolution methods perform poorly in real-world super-resolution tasks, where the paired high-resolution and low-resolution images are unavailable and the low-resolution images are degraded by complicated and unknown kernels. To break these limitations, we propose the Unsupervised Bi-directional Cycle Domain Transfer Learning-based Generative Adversarial Network (UBCDTL-GAN), which consists of an Unsupervised Bi-directional Cycle Domain Transfer Network (UBCDTN) and the Semantic Encoder guided Super Resolution Network (SESRN). First, the UBCDTN is able to produce an approximated real-like LR image through transferring the LR image from an artificially degraded domain to the real-world LR image domain. Second, the SESRN has the ability to super-resolve the approximated real-like LR image to a photo-realistic HR image. Extensive experiments on unpaired real-world image benchmark datasets demonstrate that the proposed method achieves superior performance compared to state-of-the-art methods.

We study on image super-resolution (SR), which aims to recover realistic textures from a low-resolution (LR) image. Recent progress has been made by taking high-resolution images as references (Ref), so that relevant textures can be transferred to LR images. However, existing SR approaches neglect to use attention mechanisms to transfer high-resolution (HR) textures from Ref images, which limits these approaches in challenging cases. In this paper, we propose a novel Texture Transformer Network for Image Super-Resolution (TTSR), in which the LR and Ref images are formulated as queries and keys in a transformer, respectively. TTSR consists of four closely-related modules optimized for image generation tasks, including a learnable texture extractor by DNN, a relevance embedding module, a hard-attention module for texture transfer, and a softattention module for texture synthesis. Such a design encourages joint feature learning across LR and Ref images, in which deep feature correspondences can be discovered by attention, and thus accurate texture features can be transferred. The proposed texture transformer can be further stacked in a cross-scale way, which enables texture recovery from different levels (e.g., from 1× to 4× magnification). Extensive experiments show that TTSR achieves significant improvements over state-of-the-art approaches on both quantitative and qualitative evaluations. The source code can be downloaded at https://github.com/ researchmm/TTSR.

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。