Recent years have witnessed the unprecedented success of deep convolutional neural networks (CNNs) in single image super-resolution (SISR). However, existing CNN-based SISR methods mostly assume that a low-resolution (LR) image is bicubicly downsampled from a high-resolution (HR) image, thus inevitably giving rise to poor performance when the true degradation does not follow this assumption. Moreover, they lack scalability in learning a single model to nonblindly deal with multiple degradations. To address these issues, we propose a general framework with dimensionality stretching strategy that enables a single convolutional super-resolution network to take two key factors of the SISR degradation process, i.e., blur kernel and noise level, as input. Consequently, the super-resolver can handle multiple and even spatially variant degradations, which significantly improves the practicability. Extensive experimental results on synthetic and real LR images show that the proposed convolutional super-resolution network not only can produce favorable results on multiple degradations but also is computationally efficient, providing a highly effective and scalable solution to practical SISR applications.
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Model-based optimization methods and discriminative learning methods have been the two dominant strategies for solving various inverse problems in low-level vision. Typically, those two kinds of methods have their respective merits and drawbacks, e.g., model-based optimization methods are flexible for handling different inverse problems but are usually time-consuming with sophisticated priors for the purpose of good performance; in the meanwhile, discriminative learning methods have fast testing speed but their application range is greatly restricted by the specialized task. Recent works have revealed that, with the aid of variable splitting techniques, denoiser prior can be plugged in as a modular part of model-based optimization methods to solve other inverse problems (e.g., deblurring). Such an integration induces considerable advantage when the denoiser is obtained via discriminative learning. However, the study of integration with fast discriminative denoiser prior is still lacking. To this end, this paper aims to train a set of fast and effective CNN (convolutional neural network) denoisers and integrate them into model-based optimization method to solve other inverse problems. Experimental results demonstrate that the learned set of denoisers not only achieve promising Gaussian denoising results but also can be used as prior to deliver good performance for various low-level vision applications.
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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。
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虽然最近基于模型的盲目单图像超分辨率(SISR)的研究已经取得了巨大的成功,但大多数人都不认为图像劣化。首先,它们总是假设图像噪声obeys独立和相同分布的(i.i.d.)高斯或拉普拉斯分布,这在很大程度上低估了真实噪音的复杂性。其次,以前的常用核前沿(例如,归一化,稀疏性)不足以保证理性内核解决方案,从而退化后续SISR任务的性能。为了解决上述问题,本文提出了一种基于模型的盲人SISR方法,该方法在概率框架下,从噪声和模糊内核的角度精心模仿图像劣化。具体而言,而不是传统的i.i.d.噪声假设,基于补丁的非i.i.d。提出噪声模型来解决复杂的真实噪声,期望增加噪声表示模型的自由度。至于模糊内核,我们新建构建一个简洁但有效的内核生成器,并将其插入所提出的盲人SISR方法作为明确的内核(EKP)。为了解决所提出的模型,专门设计了理论上接地的蒙特卡罗EM算法。综合实验证明了我们对综合性和实时数据集的最新技术的方法的优越性。
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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.
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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.
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尽管目前基于深度学习的方法在盲目的单图像超分辨率(SISR)任务中已获得了有希望的表现,但其中大多数主要集中在启发式上构建多样化的网络体系结构,并更少强调对Blur之间的物理发电机制的明确嵌入内核和高分辨率(HR)图像。为了减轻这个问题,我们提出了一个模型驱动的深神经网络,称为blind SISR。具体而言,为了解决经典的SISR模型,我们提出了一种简单的效果迭代算法。然后,通过将所涉及的迭代步骤展开到相应的网络模块中,我们自然构建了KXNET。所提出的KXNET的主要特异性是整个学习过程与此SISR任务的固有物理机制完全合理地集成在一起。因此,学习的模糊内核具有清晰的物理模式,并且模糊内核和HR图像之间的相互迭代过程可以很好地指导KXNET沿正确的方向发展。关于合成和真实数据的广泛实验很好地证明了我们方法的卓越准确性和一般性超出了当前代表性的最先进的盲目SISR方法。代码可在:\ url {https://github.com/jiahong-fu/kxnet}中获得。
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盲级超分辨率(SR)旨在从低分辨率(LR)图像中恢复高质量的视觉纹理,通常通过下采样模糊内核和添加剂噪声来降解。由于现实世界中复杂的图像降解的挑战,此任务非常困难。现有的SR方法要么假定预定义的模糊内核或固定噪声,这限制了这些方法在具有挑战性的情况下。在本文中,我们提出了一个用于盲目超级分辨率(DMSR)的降解引导的元修复网络,该网络促进了真实病例的图像恢复。 DMSR由降解提取器和元修复模块组成。萃取器估计LR输入中的降解,并指导元恢复模块以预测恢复参数的恢复参数。 DMSR通过新颖的降解一致性损失和重建损失共同优化。通过这样的优化,DMSR在三个广泛使用的基准上以很大的边距优于SOTA。一项包括16个受试者的用户研究进一步验证了现实世界中的盲目SR任务中DMSR的优势。
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突发超级分辨率(SR)提供了从低质量图像恢复丰富细节的可能性。然而,由于实际应用中的低分辨率(LR)图像具有多种复杂和未知的降级,所以现有的非盲(例如,双臂)设计的网络通常导致恢复高分辨率(HR)图像的严重性能下降。此外,处理多重未对准的嘈杂的原始输入也是具有挑战性的。在本文中,我们解决了从现代手持设备获取的原始突发序列重建HR图像的问题。中央观点是一个内核引导策略,可以用两个步骤解决突发SR:内核建模和HR恢复。前者估计来自原始输入的突发内核,而后者基于估计的内核预测超分辨图像。此外,我们引入了内核感知可变形对准模块,其可以通过考虑模糊的前沿而有效地对准原始图像。对综合和现实世界数据集的广泛实验表明,所提出的方法可以在爆发SR问题中对最先进的性能进行。
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近年来,在光场(LF)图像超分辨率(SR)中,深度神经网络(DNN)的巨大进展。但是,现有的基于DNN的LF图像SR方法是在单个固定降解(例如,双学的下采样)上开发的,因此不能应用于具有不同降解的超级溶解实际LF图像。在本文中,我们提出了第一种处理具有多个降解的LF图像SR的方法。在我们的方法中,开发了一个实用的LF降解模型,以近似于真实LF图像的降解过程。然后,降解自适应网络(LF-DANET)旨在将降解之前纳入SR过程。通过对具有多种合成降解的LF图像进行训练,我们的方法可以学会适应不同的降解,同时结合了空间和角度信息。对合成降解和现实世界LFS的广泛实验证明了我们方法的有效性。与现有的最新单一和LF图像SR方法相比,我们的方法在广泛的降解范围内实现了出色的SR性能,并且可以更好地推广到真实的LF图像。代码和模型可在https://github.com/yingqianwang/lf-danet上找到。
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Existing convolutional neural networks (CNN) based image super-resolution (SR) methods have achieved impressive performance on bicubic kernel, which is not valid to handle unknown degradations in real-world applications. Recent blind SR methods suggest to reconstruct SR images relying on blur kernel estimation. However, their results still remain visible artifacts and detail distortion due to the estimation errors. To alleviate these problems, in this paper, we propose an effective and kernel-free network, namely DSSR, which enables recurrent detail-structure alternative optimization without blur kernel prior incorporation for blind SR. Specifically, in our DSSR, a detail-structure modulation module (DSMM) is built to exploit the interaction and collaboration of image details and structures. The DSMM consists of two components: a detail restoration unit (DRU) and a structure modulation unit (SMU). The former aims at regressing the intermediate HR detail reconstruction from LR structural contexts, and the latter performs structural contexts modulation conditioned on the learned detail maps at both HR and LR spaces. Besides, we use the output of DSMM as the hidden state and design our DSSR architecture from a recurrent convolutional neural network (RCNN) view. In this way, the network can alternatively optimize the image details and structural contexts, achieving co-optimization across time. Moreover, equipped with the recurrent connection, our DSSR allows low- and high-level feature representations complementary by observing previous HR details and contexts at every unrolling time. Extensive experiments on synthetic datasets and real-world images demonstrate that our method achieves the state-of-the-art against existing methods. The source code can be found at https://github.com/Arcananana/DSSR.
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Convolutional neural networks have recently demonstrated high-quality reconstruction for single-image superresolution. In this paper, we propose the Laplacian Pyramid Super-Resolution Network (LapSRN) to progressively reconstruct the sub-band residuals of high-resolution images. At each pyramid level, our model takes coarse-resolution feature maps as input, predicts the high-frequency residuals, and uses transposed convolutions for upsampling to the finer level. Our method does not require the bicubic interpolation as the pre-processing step and thus dramatically reduces the computational complexity. We train the proposed LapSRN with deep supervision using a robust Charbonnier loss function and achieve high-quality reconstruction. Furthermore, our network generates multi-scale predictions in one feed-forward pass through the progressive reconstruction, thereby facilitates resource-aware applications. Extensive quantitative and qualitative evaluations on benchmark datasets show that the proposed algorithm performs favorably against the state-of-the-art methods in terms of speed and accuracy.
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单像超分辨率(SISR),作为传统的不良反对问题,通过最近的卷积神经网络(CNN)的发展得到了极大的振兴。这些基于CNN的方法通常将低分辨率图像映射到其相应的高分辨率版本,具有复杂的网络结构和损耗功能,显示出令人印象深刻的性能。本文对传统的SISR算法提供了新的洞察力,并提出了一种基本上不同的方法,依赖于迭代优化。提出了一种新颖的迭代超分辨率网络(ISRN),顶部是迭代优化。我们首先分析图像SR问题的观察模型,通过以更一般和有效的方式模仿和融合每次迭代来激发可行的解决方案。考虑到批量归一化的缺点,我们提出了一种特征归一化(F-NOM,FN)方法来调节网络中的功能。此外,开发了一种具有FN的新颖块以改善作为FNB称为FNB的网络表示。剩余剩余结构被提出形成一个非常深的网络,其中FNBS与长时间跳过连接,以获得更好的信息传递和稳定训练阶段。对BICUBIC(BI)降解的测试基准的广泛实验结果表明我们的ISRN不仅可以恢复更多的结构信息,而且还可以获得竞争或更好的PSNR / SSIM结果,与其他作品相比,参数更少。除BI之外,我们除了模拟模糊(BD)和低级噪声(DN)的实际降级。 ISRN及其延伸ISRN +两者都比使用BD和DN降级模型的其他产品更好。
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极度依赖于从划痕的模型的降级或优化的降解或优化的迭代估计,现有的盲超分辨率(SR)方法通常是耗时和效率较低,因为退化的估计从盲初始化进行并且缺乏可解释降解前沿。为了解决它,本文提出了一种使用端到端网络的盲SR的过渡学习方法,没有任何额外的推断中的额外迭代,并探讨了未知降级的有效表示。首先,我们分析并证明降解的过渡性作为可解释的先前信息,以间接推断出未知的降解模型,包括广泛使用的添加剂和卷曲降解。然后,我们提出了一种新颖的过渡性学习方法,用于盲目超分辨率(TLSR),通过自适应地推断过渡转换功能来解决未知的降级而没有推断的任何迭代操作。具体地,端到端TLSR网络包括一定程度的过渡性(点)估计网络,同一性特征提取网络和过渡学习模块。对盲人SR任务的定量和定性评估表明,拟议的TLSR实现了优异的性能,并且对最先进的盲人SR方法的复杂性较少。该代码可在github.com/yuanfeihuang/tlsr获得。
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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。
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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.
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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.
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在本文中,我们提出了一项医疗措施,以赋予超级分辨率生成对抗网络(AID-SRGAN),以实现二线图像超分辨率。首先,我们提出了一种医学实践降解模型,该模型考虑了除了减少采样以外的各种退化因素。据我们所知,这是针对射线照相图像提出的第一个复合降解模型。此外,我们提出了AID-SRGAN,它可以同时降低并产生高分辨率(HR)X光片。在此模型中,我们将注意力机制引入了Denoising模块中,以使其对复杂的降解更加健壮。最后,SR模块使用“清洁”低分辨率(LR)X光片重建HR X光片。此外,我们提出了一种单独的接头训练方法来训练模型,并进行了广泛的实验,以表明所提出的方法优于其对应物。例如,我们提出的方法可实现$ 31.90 $的PSNR,比例为$ 4 \ times $,比最近的工作SPSR [16]高7.05美元\%$ $ $。我们的数据集和代码将在以下网址提供:https://github.com/yongsongh/aidsrgan-miccai2022。
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为了在盲图超级分辨率(SR)上取得有希望的结果,一些尝试利用低分辨率(LR)图像来预测内核并改善SR性能。但是,由于不可用的现实世界模糊内核,这些监督的内核预测(SKP)方法是不切实际的。尽管提出了一些无监督的降解预测(UDP)方法来绕过此问题,但\ textIt {contercestency}之间的降解嵌入和SR功能之间仍然具有挑战性。通过探索降解嵌入与SR功能之间的相关性,我们观察到共同学习内容和降解感知功能是最佳的。基于此观察结果,提出了一个名为CDSR的内容和退化的SR网络。具体而言,CDSR包含三个新建立的模块:(1)将基于重量的编码器(LPE)应用于共同提取内容和降解功能; (2)采用基于域查询的基于注意力的模块(DQA)来适应不一致; (3)基于密码的空格压缩模块(CSC),可以抑制冗余信息。对几个基准测试的广泛实验表明,即使与最先进的SKP方法相比,提议的CDSR的表现都优于现有的UDP模型,并在PSNR和SSIM上实现竞争性能。
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在本文中,我们考虑了基于参考的超分辨率(REFSR)中的两个具有挑战性的问题,(i)如何选择适当的参考图像,以及(ii)如何以一种自我监督的方式学习真实世界RefSR。特别是,我们从双摄像头Zooms(SelfDZSR)观察到现实世界图像SR的新颖的自我监督学习方法。考虑到多台相机在现代智能手机中的普及,可以自然利用越来越多的缩放(远摄)图像作为指导较小的变焦(短对焦)图像的SR。此外,SelfDZSR学习了一个深层网络,以获得短对焦图像的SR结果,以具有与远摄图像相同的分辨率。为此,我们将远摄图像而不是其他高分辨率图像作为监督信息,然后从中选择中心贴片作为对相应的短对焦图像补丁的引用。为了减轻短对焦低分辨率(LR)图像和远摄地面真相(GT)图像之间未对准的影响,我们设计了辅助LR发电机,并将GT映射到辅助LR,同时保持空间位置不变。 。然后,可以利用辅助-LR通过建议的自适应空间变压器网络(ADASTN)将LR特征变形,并将REF特征与GT匹配。在测试过程中,可以直接部署SelfDZSR,以使用远摄映像的引用来超级解决整个短对焦图像。实验表明,我们的方法可以针对最先进的方法实现更好的定量和定性性能。代码可在https://github.com/cszhilu1998/selfdzsr上找到。
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