中心位置是否完全能够代表像素？在离散的图像表示中表示具有它们的中心的像素的错误，但是在图像超分辨率（SR）上下文中的局域脉中的信号的聚合时，它更有意义地考虑每个像素。尽管任意级图像SR领域的基于坐标的隐式表示的能力很大，但该区域的像素的性质不完全考虑。为此，我们提出了集成的位置编码（IPE），通过聚合在像素区域上聚合频率信息来扩展传统的位置编码。我们将IPE应用于最先进的任意级图像超分辨率方法：本地隐式图像功能（LIIF），呈现IPE-LIIF。我们通过定量和定性评估显示IPE-LIIF的有效性，并进一步证明了IPE泛化能力与更大的图像尺度和基于多种隐式的方法。代码将被释放。

NERF和其他相关隐式神经表示方法的最新成功为连续图像表示打开了一条新的途径，其中不再需要从存储的离散2D阵列中查找像素值，但可以从连续空间域上的神经网络模型推断出来。尽管LIIF最近的工作表明，这种新颖的方法可以在任意尺度的超分辨率任务上实现良好的性能，但由于对高频纹理的预测不准确，它们的高尺度图像经常显示出结构性失真。在这项工作中，我们提出了UltraSR，这是一种基于隐式图像函数的简单而有效的新网络设计，在其中我们深入整合了空间坐标和与隐式神经表示的定期编码。通过广泛的实验和消融研究，我们表明空间编码是朝向下一个阶段高表现隐式图像函数的缺失钥匙。与以前的最先进的方法相比，我们的Ultrasr在所有超分辨率量表下在DIV2K基准测试中设定了新的最先进的性能。 Ultrasr还可以在其他标准基准数据集上实现卓越的性能，在这些数据集中，它在几乎所有实验中都优于先前的工作。

如今，由于屏幕共享，远程合作和在线教育的广泛应用，屏幕内容存在爆炸性增长。为了匹配有限终端带宽，可以缩小高分辨率（HR）屏幕内容并压缩。在接收器侧，低分辨率（LR）屏幕内容图像（SCI）的超分辨率（SR）由HR显示器或用户缩小以供详细观察。然而，由于图像特性非常不同的图像特性以及在任意尺度下浏览的SCI浏览要求，图像SR方法主要针对自然图像设计不概括SCI。为此，我们为SCISR提出了一种新颖的隐式变压器超分辨率网络（ITSRN）。对于任意比率的高质量连续SR，通过所提出的隐式变压器从密钥坐标处的图像特征推断出查询坐标处的像素值，并且提出了隐式位置编码方案来聚合与查询相似的相邻像素值。使用LR和HR SCI对构建基准SCI1K和SCI1K压缩数据集。广泛的实验表明，提出的ITSRN显着优于压缩和未压缩的SCI的几种竞争连续和离散SR方法。

How to represent an image? While the visual world is presented in a continuous manner, machines store and see the images in a discrete way with 2D arrays of pixels. In this paper, we seek to learn a continuous representation for images. Inspired by the recent progress in 3D reconstruction with implicit neural representation, we propose Local Implicit Image Function (LIIF), which takes an image coordinate and the 2D deep features around the coordinate as inputs, predicts the RGB value at a given coordinate as an output. Since the coordinates are continuous, LIIF can be presented in arbitrary resolution. To generate the continuous representation for images, we train an encoder with LIIF representation via a self-supervised task with superresolution. The learned continuous representation can be presented in arbitrary resolution even extrapolate to ×30 higher resolution, where the training tasks are not provided. We further show that LIIF representation builds a bridge between discrete and continuous representation in 2D, it naturally supports the learning tasks with size-varied image ground-truths and significantly outperforms the method with resizing the ground-truths. Our project page with code is at https://yinboc.github.io/liif/.

最近有一种隐式神经功能棚灯，代表任意分辨率的图像。然而，独立的多层Perceptron（MLP）在学习高频分量中显示了有限的性能。在本文中，我们提出了一种局部纹理估计器（LTE），用于自然图像的主要频率估计器，使得隐式功能以连续方式重建图像的同时捕获精细细节。当用深层超分辨率（SR）架构共同培训时，LTE能够在2D傅里叶空间中表征图像纹理。我们表明，基于LTE的神经功能优于所有数据集的任意级别的现有深度SR方法，以及所有规模因素。此外，与以前的作品相比，我们的实施呈现了最短的运行时间。源代码将打开。

高光谱图像（HSI）没有额外辅助图像的超分辨率仍然是由于其高维光谱图案的恒定挑战，其中学习有效的空间和光谱表示是基本问题。最近，隐式的神经表示（INR）正在进行进步，作为新颖且有效的代表，特别是在重建任务中。因此，在这项工作中，我们提出了一种基于INR的新颖的HSI重建模型，其通过将空间坐标映射到其对应的光谱辐射值值的连续函数来表示HSI。特别地，作为INR的特定实现，参数模型的参数是通过使用卷积网络在特征提取的超通知来预测的。它使连续功能以内容感知方式将空间坐标映射到像素值。此外，周期性空间编码与重建过程深度集成，这使得我们的模型能够恢复更高的频率细节。为了验证我们模型的功效，我们在三个HSI数据集（洞穴，NUS和NTIRE2018）上进行实验。实验结果表明，与最先进的方法相比，该建议的模型可以实现竞争重建性能。此外，我们提供了对我们模型各个组件的效果的消融研究。我们希望本文可以服务器作为未来研究的效率参考。

图像表示对于许多视觉任务至关重要。最近的一项研究，即局部隐式图像函数（LIIF），而不是用2D阵列代替图像，而是将图像表示为连续函数，其中像素值是通过使用相应的坐标作为输入来扩展的。由于其连续的性质，可以为任意规模的图像超分辨率任务采用LIIF，从而为各种提高因素提供了一个有效和有效的模型。但是，Liif通常遭受边缘周围的结构扭曲和响起的伪影，主要是因为所有像素共享相同的模型，因此忽略了图像的局部特性。在本文中，我们提出了一种新颖的自适应局部图像功能（A-LIIF）来减轻此问题。具体而言，我们的A-LIIF由两个主要组成部分组成：编码器和扩展网络。前者捕获了跨尺度的图像特征，而后者通过多个局部隐式图像函数的加权组合进行了连续升级函数。因此，我们的A-LIIF可以更准确地重建高频纹理和结构。多个基准数据集的实验验证了我们方法的有效性。我们的代码可在\ url {https://github.com/leehw-thu/a-liif}上找到。

360 {\ Deg}成像最近遭受了很大的关注;然而，其角度分辨率比窄视野（FOV）透视图像相对较低，因为它通过使用具有相同传感器尺寸的鱼眼透镜而被捕获。因此，它有利于超声解析360 {\ DEG}图像。已经制造了一些尝试，但大多数是常规的投影（ERP），尽管尽管存在纬度依赖性失真，但仍然是360 {\ DEG}图像表示的方式之一。在这种情况下，随着输出高分辨率（HR）图像始终处于与低分辨率（LR）输入相同的ERP格式，当将HR图像转换为其他投影类型时可能发生另一信息丢失。在本文中，我们提出了从LR 360 {\ Deg}图像产生连续球面图像表示的新颖框架，旨在通过任意360 {\ deg}预测给定球形坐标处的RGB值。图像投影。具体地，我们首先提出了一种特征提取模块，该特征提取模块表示基于IcosaheDron的球面数据，并有效地提取球面上的特征。然后，我们提出了一种球形本地隐式图像功能（SLIIF）来预测球形坐标处的RGB值。这样，Spheresr在任意投影型下灵活地重建HR图像。各种基准数据集的实验表明，我们的方法显着超越了现有方法。

Learning continuous image representations is recently gaining popularity for image super-resolution (SR) because of its ability to reconstruct high-resolution images with arbitrary scales from low-resolution inputs. Existing methods mostly ensemble nearby features to predict the new pixel at any queried coordinate in the SR image. Such a local ensemble suffers from some limitations: i) it has no learnable parameters and it neglects the similarity of the visual features; ii) it has a limited receptive field and cannot ensemble relevant features in a large field which are important in an image; iii) it inherently has a gap with real camera imaging since it only depends on the coordinate. To address these issues, this paper proposes a continuous implicit attention-in-attention network, called CiaoSR. We explicitly design an implicit attention network to learn the ensemble weights for the nearby local features. Furthermore, we embed a scale-aware attention in this implicit attention network to exploit additional non-local information. Extensive experiments on benchmark datasets demonstrate CiaoSR significantly outperforms the existing single image super resolution (SISR) methods with the same backbone. In addition, the proposed method also achieves the state-of-the-art performance on the arbitrary-scale SR task. The effectiveness of the method is also demonstrated on the real-world SR setting. More importantly, CiaoSR can be flexibly integrated into any backbone to improve the SR performance.

我们呈现NERF-SR，一种用于高分辨率（HR）新型视图合成的解决方案，主要是低分辨率（LR）输入。我们的方法是基于神经辐射场（NERF）的内置，其预测每点密度和颜色，具有多层的射击。在在任意尺度上产生图像时，NERF与超越观察图像的分辨率努力。我们的关键识别是NERF具有本地之前的，这意味着可以在附近区域传播3D点的预测，并且保持准确。我们首先通过超级采样策略来利用它，该策略在每个图像像素处射击多个光线，这在子像素级别强制了多视图约束。然后，我们表明，NERF-SR可以通过改进网络进一步提高超级采样的性能，该细化网络利用估计的深度来实现HR参考图像上的相关补丁的幻觉。实验结果表明，NERF-SR在合成和现实世界数据集的HR上为新型视图合成产生高质量结果。

图像翘曲的目的是将矩形网格定义的图像重新设计为任意形状。最近，隐式神经功能在以连续方式表示图像时表现出了显着的性能。然而，独立的多层感知器受到学习高频傅立叶系数的影响。在本文中，我们提出了图像翘曲（LTEW）的局部纹理估计器，然后提出隐式神经表示，以将图像变形为连续形状。从深度超分辨率（SR）主链估计的局部纹理乘以坐标转换的局部变化雅各布矩阵，以预测扭曲的图像的傅立叶响应。我们的基于LTEW的神经功能优于现有的扭曲方法，用于不对称尺度的SR和跨术变换。此外，我们的算法很好地概括了任意坐标变换，例如具有较大放大因子和等应角投影（ERP）的透视变换，这些变换在训练中未提供。

This paper explores the problem of reconstructing high-resolution light field (LF) images from hybrid lenses, including a high-resolution camera surrounded by multiple low-resolution cameras. The performance of existing methods is still limited, as they produce either blurry results on plain textured areas or distortions around depth discontinuous boundaries. To tackle this challenge, we propose a novel end-to-end learning-based approach, which can comprehensively utilize the specific characteristics of the input from two complementary and parallel perspectives. Specifically, one module regresses a spatially consistent intermediate estimation by learning a deep multidimensional and cross-domain feature representation, while the other module warps another intermediate estimation, which maintains the high-frequency textures, by propagating the information of the high-resolution view. We finally leverage the advantages of the two intermediate estimations adaptively via the learned attention maps, leading to the final high-resolution LF image with satisfactory results on both plain textured areas and depth discontinuous boundaries. Besides, to promote the effectiveness of our method trained with simulated hybrid data on real hybrid data captured by a hybrid LF imaging system, we carefully design the network architecture and the training strategy. Extensive experiments on both real and simulated hybrid data demonstrate the significant superiority of our approach over state-of-the-art ones. To the best of our knowledge, this is the first end-to-end deep learning method for LF reconstruction from a real hybrid input. We believe our framework could potentially decrease the cost of high-resolution LF data acquisition and benefit LF data storage and transmission.

Neural volumetric representations have become a widely adopted model for radiance fields in 3D scenes. These representations are fully implicit or hybrid function approximators of the instantaneous volumetric radiance in a scene, which are typically learned from multi-view captures of the scene. We investigate the new task of neural volume super-resolution - rendering high-resolution views corresponding to a scene captured at low resolution. To this end, we propose a neural super-resolution network that operates directly on the volumetric representation of the scene. This approach allows us to exploit an advantage of operating in the volumetric domain, namely the ability to guarantee consistent super-resolution across different viewing directions. To realize our method, we devise a novel 3D representation that hinges on multiple 2D feature planes. This allows us to super-resolve the 3D scene representation by applying 2D convolutional networks on the 2D feature planes. We validate the proposed method's capability of super-resolving multi-view consistent views both quantitatively and qualitatively on a diverse set of unseen 3D scenes, demonstrating a significant advantage over existing approaches.

High Resolution (HR) medical images provide rich anatomical structure details to facilitate early and accurate diagnosis. In MRI, restricted by hardware capacity, scan time, and patient cooperation ability, isotropic 3D HR image acquisition typically requests long scan time and, results in small spatial coverage and low SNR. Recent studies showed that, with deep convolutional neural networks, isotropic HR MR images could be recovered from low-resolution (LR) input via single image super-resolution (SISR) algorithms. However, most existing SISR methods tend to approach a scale-specific projection between LR and HR images, thus these methods can only deal with a fixed up-sampling rate. For achieving different up-sampling rates, multiple SR networks have to be built up respectively, which is very time-consuming and resource-intensive. In this paper, we propose ArSSR, an Arbitrary Scale Super-Resolution approach for recovering 3D HR MR images. In the ArSSR model, the reconstruction of HR images with different up-scaling rates is defined as learning a continuous implicit voxel function from the observed LR images. Then the SR task is converted to represent the implicit voxel function via deep neural networks from a set of paired HR-LR training examples. The ArSSR model consists of an encoder network and a decoder network. Specifically, the convolutional encoder network is to extract feature maps from the LR input images and the fully-connected decoder network is to approximate the implicit voxel function. Due to the continuity of the learned function, a single ArSSR model can achieve arbitrary up-sampling rate reconstruction of HR images from any input LR image after training. Experimental results on three datasets show that the ArSSR model can achieve state-of-the-art SR performance for 3D HR MR image reconstruction while using a single trained model to achieve arbitrary up-sampling scales.

The rendering procedure used by neural radiance fields (NeRF) samples a scene with a single ray per pixel and may therefore produce renderings that are excessively blurred or aliased when training or testing images observe scene content at different resolutions. The straightforward solution of supersampling by rendering with multiple rays per pixel is impractical for NeRF, because rendering each ray requires querying a multilayer perceptron hundreds of times. Our solution, which we call "mip-NeRF" (à la "mipmap"), extends NeRF to represent the scene at a continuously-valued scale. By efficiently rendering anti-aliased conical frustums instead of rays, mip-NeRF reduces objectionable aliasing artifacts and significantly improves NeRF's ability to represent fine details, while also being 7% faster than NeRF and half the size. Compared to NeRF, mip-NeRF reduces average error rates by 17% on the dataset presented with NeRF and by 60% on a challenging multiscale variant of that dataset that we present. Mip-NeRF is also able to match the accuracy of a brute-force supersampled NeRF on our multiscale dataset while being 22× faster.

视频通常将流和连续的视觉数据记录为离散的连续帧。由于存储成本对于高保真度的视频来说是昂贵的，因此大多数存储以相对较低的分辨率和帧速率存储。最新的时空视频超分辨率（STVSR）的工作是开发出来的，以将时间插值和空间超分辨率纳入统一框架。但是，其中大多数仅支持固定的上采样量表，这限制了其灵活性和应用。在这项工作中，我们没有遵循离散表示，我们提出了视频隐式神经表示（videoinr），并显示了其对STVSR的应用。学到的隐式神经表示可以解码为任意空间分辨率和帧速率的视频。我们表明，Videoinr在常见的上采样量表上使用最先进的STVSR方法实现了竞争性能，并且在连续和训练的分布量表上显着优于先前的作品。我们的项目页面位于http://zeyuan-chen.com/videoinr/。

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.

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。

基于坐标的网络成为3D表示和场景重建的强大工具。这些网络训练以将连续输入坐标映射到每个点处的信号的值。尽管如此，当前的架构是黑色盒子：不能轻易分析它们的光谱特性，并且在无监督点处的行为难以预测。此外，这些网络通常接受训练以以单个刻度表示信号，并且如此天真的下采样或上采样导致伪像。我们引入带限量坐标网络（BACON），具有分析傅里叶谱的网络架构。培根在无监督点处具有可预测的行为，可以基于所代表信号的光谱特性设计，并且可以在没有明确的监督的情况下代表多个尺度的信号。我们向培根展示用于使用符号距离功能的图像，辐射字段和3D场景的多尺度神经表示的培根，并表明它在可解释性和质量方面优于传统的单尺度坐标网络。

具有窄光谱带的高光谱图像（HSI）可以捕获丰富的光谱信息，但它在该过程中牺牲其空间分辨率。最近提出了许多基于机器学习的HSI超分辨率（SR）算法。然而，这些方法的基本限制之一是它们高度依赖于图像和相机设置，并且只能学会用另一个特定设置用一个特定的设置映射输入的HSI。然而，由于HSI相机的多样性，不同的相机捕获具有不同光谱响应函数和频带编号的图像。因此，现有的基于机器学习的方法无法学习用于各种输入输出频带设置的超声波HSIS。我们提出了一种基于元学习的超分辨率（MLSR）模型，其可以在任意数量的输入频带'峰值波长下采用HSI图像，并产生具有任意数量的输出频带'峰值波长的SR HSIS。我们利用NTIRE2020和ICVL数据集训练并验证MLSR模型的性能。结果表明，单个提出的模型可以在任意输入 - 输出频带设置下成功生成超分辨的HSI频段。结果更好或至少与在特定输入输出频带设置上单独培训的基线相当。