Generative adversarial networks (GANs) provide a way to learn deep representations without extensively annotated training data. They achieve this through deriving backpropagation signals through a competitive process involving a pair of networks. The representations that can be learned by GANs may be used in a variety of applications, including image synthesis, semantic image editing, style transfer, image super-resolution and classification. The aim of this review paper is to provide an overview of GANs for the signal processing community, drawing on familiar analogies and concepts where possible. In addition to identifying different methods for training and constructing GANs, we also point to remaining challenges in their theory and application.

与CNN的分类，分割或对象检测相比，生成网络的目标和方法根本不同。最初，它们不是作为图像分析工具，而是生成自然看起来的图像。已经提出了对抗性训练范式来稳定生成方法，并已被证明是非常成功的 - 尽管绝不是第一次尝试。本章对生成对抗网络（GAN）的动机进行了基本介绍，并通​​过抽象基本任务和工作机制并得出了早期实用方法的困难来追溯其成功的道路。将显示进行更稳定的训练方法，也将显示出不良收敛及其原因的典型迹象。尽管本章侧重于用于图像生成和图像分析的gan，但对抗性训练范式本身并非特定于图像，并且在图像分析中也概括了任务。在将GAN与最近进入场景的进一步生成建模方法进行对比之前，将闻名图像语义分割和异常检测的架构示例。这将允许对限制的上下文化观点，但也可以对gans有好处。

这是关于生成对抗性网络（GaN），对抗性自身额外的教程和调查纸张及其变体。我们开始解释对抗性学习和香草甘。然后，我们解释了条件GaN和DCGAN。介绍了模式崩溃问题，介绍了各种方法，包括小纤维GaN，展开GaN，Bourgan，混合GaN，D2Gan和Wasserstein GaN，用于解决这个问题。然后，GaN中的最大似然估计与F-GaN，对抗性变分贝叶斯和贝叶斯甘甘相同。然后，我们涵盖了GaN，Infogan，Gran，Lsgan，Enfogan，Gran，Lsgan，Catgan，MMD Gan，Lapgan，Progressive Gan，Triple Gan，Lag，Gman，Adagan，Cogan，逆甘，Bigan，Ali，Sagan，Sagan，Sagan，Sagan，甘肃，甘肃，甘河的插值和评估。然后，我们介绍了GaN的一些应用，例如图像到图像转换（包括Pacchgan，Cyclegan，Deepfacedrawing，模拟GaN，Interactive GaN），文本到图像转换（包括Stackgan）和混合图像特征（包括罚球和mixnmatch）。最后，我们解释了基于对冲学习的AutoEncoders，包括对手AutoEncoder，Pixelgan和隐式AutoEncoder。

从文本描述中综合现实图像是计算机视觉中的主要挑战。当前对图像合成方法的文本缺乏产生代表文本描述符的高分辨率图像。大多数现有的研究都依赖于生成的对抗网络（GAN）或变异自动编码器（VAE）。甘斯具有产生更清晰的图像的能力，但缺乏输出的多样性，而VAE擅长生产各种输出，但是产生的图像通常是模糊的。考虑到gan和vaes的相对优势，我们提出了一个新的有条件VAE（CVAE）和条件gan（CGAN）网络架构，用于合成以文本描述为条件的图像。这项研究使用条件VAE作为初始发电机来生成文本描述符的高级草图。这款来自第一阶段的高级草图输出和文本描述符被用作条件GAN网络的输入。第二阶段GAN产生256x256高分辨率图像。所提出的体系结构受益于条件加强和有条件的GAN网络的残留块，以实现结果。使用CUB和Oxford-102数据集进行了多个实验，并将所提出方法的结果与Stackgan等最新技术进行了比较。实验表明，所提出的方法生成了以文本描述为条件的高分辨率图像，并使用两个数据集基于Inception和Frechet Inception评分产生竞争结果

Our goal with this survey is to provide an overview of the state of the art deep learning technologies for face generation and editing. We will cover popular latest architectures and discuss key ideas that make them work, such as inversion, latent representation, loss functions, training procedures, editing methods, and cross domain style transfer. We particularly focus on GAN-based architectures that have culminated in the StyleGAN approaches, which allow generation of high-quality face images and offer rich interfaces for controllable semantics editing and preserving photo quality. We aim to provide an entry point into the field for readers that have basic knowledge about the field of deep learning and are looking for an accessible introduction and overview.

这是一门专门针对STEM学生开发的介绍性机器学习课程。我们的目标是为有兴趣的读者提供基础知识，以在自己的项目中使用机器学习，并将自己熟悉术语作为进一步阅读相关文献的基础。在这些讲义中，我们讨论受监督，无监督和强化学习。注释从没有神经网络的机器学习方法的说明开始，例如原理分析，T-SNE，聚类以及线性回归和线性分类器。我们继续介绍基本和先进的神经网络结构，例如密集的进料和常规神经网络，经常性的神经网络，受限的玻尔兹曼机器，（变性）自动编码器，生成的对抗性网络。讨论了潜在空间表示的解释性问题，并使用梦和对抗性攻击的例子。最后一部分致力于加强学习，我们在其中介绍了价值功能和政策学习的基本概念。

In biomedical image analysis, the applicability of deep learning methods is directly impacted by the quantity of image data available. This is due to deep learning models requiring large image datasets to provide high-level performance. Generative Adversarial Networks (GANs) have been widely utilized to address data limitations through the generation of synthetic biomedical images. GANs consist of two models. The generator, a model that learns how to produce synthetic images based on the feedback it receives. The discriminator, a model that classifies an image as synthetic or real and provides feedback to the generator. Throughout the training process, a GAN can experience several technical challenges that impede the generation of suitable synthetic imagery. First, the mode collapse problem whereby the generator either produces an identical image or produces a uniform image from distinct input features. Second, the non-convergence problem whereby the gradient descent optimizer fails to reach a Nash equilibrium. Thirdly, the vanishing gradient problem whereby unstable training behavior occurs due to the discriminator achieving optimal classification performance resulting in no meaningful feedback being provided to the generator. These problems result in the production of synthetic imagery that is blurry, unrealistic, and less diverse. To date, there has been no survey article outlining the impact of these technical challenges in the context of the biomedical imagery domain. This work presents a review and taxonomy based on solutions to the training problems of GANs in the biomedical imaging domain. This survey highlights important challenges and outlines future research directions about the training of GANs in the domain of biomedical imagery.

由于能够产生与实际数据的显着统计相似性的高质量数据，生成的对抗性网络（GANS）最近在AI社区中引起了相当大的关注。从根本上，GaN是在训练中以越野方式训练的两个神经网络之间的游戏，以达到零和纳什均衡轮廓。尽管在过去几年中在GAN完成了改进，但仍有几个问题仍有待解决。本文评论了GANS游戏理论方面的文献，并解决了游戏理论模型如何应对生成模型的特殊挑战，提高GAN的表现。我们首先提出一些预备，包括基本GaN模型和一些博弈论背景。然后，我们将分类系统将最先进的解决方案分为三个主要类别：修改的游戏模型，修改的架构和修改的学习方法。分类基于通过文献中提出的游戏理论方法对基本GaN模型进行的修改。然后，我们探讨每个类别的目标，并讨论每个类别的最新作品。最后，我们讨论了这一领域的剩余挑战，并提出了未来的研究方向。

Generative models, as an important family of statistical modeling, target learning the observed data distribution via generating new instances. Along with the rise of neural networks, deep generative models, such as variational autoencoders (VAEs) and generative adversarial network (GANs), have made tremendous progress in 2D image synthesis. Recently, researchers switch their attentions from the 2D space to the 3D space considering that 3D data better aligns with our physical world and hence enjoys great potential in practice. However, unlike a 2D image, which owns an efficient representation (i.e., pixel grid) by nature, representing 3D data could face far more challenges. Concretely, we would expect an ideal 3D representation to be capable enough to model shapes and appearances in details, and to be highly efficient so as to model high-resolution data with fast speed and low memory cost. However, existing 3D representations, such as point clouds, meshes, and recent neural fields, usually fail to meet the above requirements simultaneously. In this survey, we make a thorough review of the development of 3D generation, including 3D shape generation and 3D-aware image synthesis, from the perspectives of both algorithms and more importantly representations. We hope that our discussion could help the community track the evolution of this field and further spark some innovative ideas to advance this challenging task.

Deep domain adaptation has emerged as a new learning technique to address the lack of massive amounts of labeled data. Compared to conventional methods, which learn shared feature subspaces or reuse important source instances with shallow representations, deep domain adaptation methods leverage deep networks to learn more transferable representations by embedding domain adaptation in the pipeline of deep learning. There have been comprehensive surveys for shallow domain adaptation, but few timely reviews the emerging deep learning based methods. In this paper, we provide a comprehensive survey of deep domain adaptation methods for computer vision applications with four major contributions. First, we present a taxonomy of different deep domain adaptation scenarios according to the properties of data that define how two domains are diverged. Second, we summarize deep domain adaptation approaches into several categories based on training loss, and analyze and compare briefly the state-of-the-art methods under these categories. Third, we overview the computer vision applications that go beyond image classification, such as face recognition, semantic segmentation and object detection. Fourth, some potential deficiencies of current methods and several future directions are highlighted.

Deep learning has produced state-of-the-art results for a variety of tasks. While such approaches for supervised learning have performed well, they assume that training and testing data are drawn from the same distribution, which may not always be the case. As a complement to this challenge, single-source unsupervised domain adaptation can handle situations where a network is trained on labeled data from a source domain and unlabeled data from a related but different target domain with the goal of performing well at test-time on the target domain. Many single-source and typically homogeneous unsupervised deep domain adaptation approaches have thus been developed, combining the powerful, hierarchical representations from deep learning with domain adaptation to reduce reliance on potentially-costly target data labels. This survey will compare these approaches by examining alternative methods, the unique and common elements, results, and theoretical insights. We follow this with a look at application areas and open research directions.

Many image-to-image translation problems are ambiguous, as a single input image may correspond to multiple possible outputs. In this work, we aim to model a distribution of possible outputs in a conditional generative modeling setting. The ambiguity of the mapping is distilled in a low-dimensional latent vector, which can be randomly sampled at test time. A generator learns to map the given input, combined with this latent code, to the output. We explicitly encourage the connection between output and the latent code to be invertible. This helps prevent a many-to-one mapping from the latent code to the output during training, also known as the problem of mode collapse, and produces more diverse results. We explore several variants of this approach by employing different training objectives, network architectures, and methods of injecting the latent code. Our proposed method encourages bijective consistency between the latent encoding and output modes. We present a systematic comparison of our method and other variants on both perceptual realism and diversity.

随着脑成像技术和机器学习工具的出现，很多努力都致力于构建计算模型来捕获人脑中的视觉信息的编码。最具挑战性的大脑解码任务之一是通过功能磁共振成像（FMRI）测量的脑活动的感知自然图像的精确重建。在这项工作中，我们调查了来自FMRI的自然图像重建的最新学习方法。我们在架构设计，基准数据集和评估指标方面检查这些方法，并在标准化评估指标上呈现公平的性能评估。最后，我们讨论了现有研究的优势和局限，并提出了潜在的未来方向。

这项工作提出了一种新的计算框架，用于学习用于真实数据集的明确生成模型。特别地，我们建议在包含多个独立的多维线性子空间组成的特征空间中的多类多维数据分发和{线性判别表示（LDR）}之间学习{\ EM闭环转录}。特别地，我们认为寻求的最佳编码和解码映射可以被配制为编码器和解码器之间的{\ em二手最小游戏的均衡点}。该游戏的自然实用功能是所谓的{\ em速率减少}，这是一个简单的信息定理措施，用于特征空间中子空间类似的高斯的混合物之间的距离。我们的配方利用来自控制系统的闭环误差反馈的灵感，避免昂贵的评估和最小化数据空间或特征空间的任意分布之间的近似距离。在很大程度上，这种新的制定统一了自动编码和GaN的概念和益处，并自然将它们扩展到学习多级和多维实际数据的判别和生成}表示的设置。我们对许多基准图像数据集的广泛实验表明了这种新的闭环配方的巨大潜力：在公平的比较下，学习的解码器的视觉质量和编码器的分类性能是竞争力的，并且通常比基于GaN，VAE或基于GaN，VAE或基于GaN，VAE的方法更好的方法两者的组合。我们注意到所以，不同类别的特征在特征空间中明确地映射到大约{em独立的主管子空间};每个类中的不同视觉属性由每个子空间中的{\ em独立主体组件}建模。

生成照片 - 现实图像，语义编辑和表示学习是高分辨率生成模型的许多潜在应用中的一些。最近在GAN的进展将它们建立为这些任务的绝佳选择。但是，由于它们不提供推理模型，因此使用GaN潜在空间无法在实际图像上完成诸如分类的图像编辑或下游任务。尽管培训了训练推理模型或设计了一种迭代方法来颠覆训练有素的发生器，但之前的方法是数据集（例如人类脸部图像）和架构（例如样式）。这些方法是非延伸到新型数据集或架构的。我们提出了一般框架，该框架是不可知的架构和数据集。我们的主要识别是，通过培训推断和生成模型在一起，我们允许它们彼此适应并收敛到更好的质量模型。我们的\ textbf {invang}，可逆GaN的简短，成功将真实图像嵌入到高质量的生成模型的潜在空间。这使我们能够执行图像修复，合并，插值和在线数据增强。我们展示了广泛的定性和定量实验。

Unsupervised learning with generative adversarial networks (GANs) has proven hugely successful. Regular GANs hypothesize the discriminator as a classifier with the sigmoid cross entropy loss function. However, we found that this loss function may lead to the vanishing gradients problem during the learning process. To overcome such a problem, we propose in this paper the Least Squares Generative Adversarial Networks (LS-GANs) which adopt the least squares loss function for the discriminator. We show that minimizing the objective function of LSGAN yields minimizing the Pearson χ 2 divergence. There are two benefits of LSGANs over regular GANs. First, LSGANs are able to generate higher quality images than regular GANs. Second, LSGANs perform more stable during the learning process. We evaluate LSGANs on five scene datasets and the experimental results show that the images generated by LSGANs are of better quality than the ones generated by regular GANs. We also conduct two comparison experiments between LSGANs and regular GANs to illustrate the stability of LSGANs.

对机器学习和创造力领域的兴趣越来越大。这项调查概述了计算创造力理论，关键机器学习技术（包括生成深度学习）和相应的自动评估方法的历史和现状。在对该领域的主要贡献进行了批判性讨论之后，我们概述了当前的研究挑战和该领域的新兴机会。

The success of machine learning algorithms generally depends on data representation, and we hypothesize that this is because different representations can entangle and hide more or less the different explanatory factors of variation behind the data. Although specific domain knowledge can be used to help design representations, learning with generic priors can also be used, and the quest for AI is motivating the design of more powerful representation-learning algorithms implementing such priors. This paper reviews recent work in the area of unsupervised feature learning and deep learning, covering advances in probabilistic models, auto-encoders, manifold learning, and deep networks. This motivates longer-term unanswered questions about the appropriate objectives for learning good representations, for computing representations (i.e., inference), and the geometrical connections between representation learning, density estimation and manifold learning.

DeNoising扩散模型代表了计算机视觉中最新的主题，在生成建模领域表现出了显着的结果。扩散模型是一个基于两个阶段的深层生成模型，一个正向扩散阶段和反向扩散阶段。在正向扩散阶段，通过添加高斯噪声，输入数据在几个步骤中逐渐受到干扰。在反向阶段，模型的任务是通过学习逐步逆转扩散过程来恢复原始输入数据。尽管已知的计算负担，即由于采样过程中涉及的步骤数量，扩散模型对生成样品的质量和多样性得到了广泛赞赏。在这项调查中，我们对视觉中应用的denoising扩散模型的文章进行了全面综述，包括该领域的理论和实际贡献。首先，我们识别并介绍了三个通用扩散建模框架，这些框架基于扩散概率模型，噪声调节得分网络和随机微分方程。我们进一步讨论了扩散模型与其他深层生成模型之间的关系，包括变异自动编码器，生成对抗网络，基于能量的模型，自回归模型和正常流量。然后，我们介绍了计算机视觉中应用的扩散模型的多角度分类。最后，我们说明了扩散模型的当前局限性，并设想了一些有趣的未来研究方向。

In data-driven systems, data exploration is imperative for making real-time decisions. However, big data is stored in massive databases that are difficult to retrieve. Approximate Query Processing (AQP) is a technique for providing approximate answers to aggregate queries based on a summary of the data (synopsis) that closely replicates the behavior of the actual data, which can be useful where an approximate answer to the queries would be acceptable in a fraction of the real execution time. In this paper, we discuss the use of Generative Adversarial Networks (GANs) for generating tabular data that can be employed in AQP for synopsis construction. We first discuss the challenges associated with constructing synopses in relational databases and then introduce solutions to those challenges. Following that, we organized statistical metrics to evaluate the quality of the generated synopses. We conclude that tabular data complexity makes it difficult for algorithms to understand relational database semantics during training, and improved versions of tabular GANs are capable of constructing synopses to revolutionize data-driven decision-making systems.