Labels to Facade BW to Color Aerial to Map Labels to Street Scene Edges to Photo input output input input input input output output output output input output Day to Night Figure 1: Many problems in image processing, graphics, and vision involve translating an input image into a corresponding output image.These problems are often treated with application-specific algorithms, even though the setting is always the same: map pixels to pixels. Conditional adversarial nets are a general-purpose solution that appears to work well on a wide variety of these problems. Here we show results of the method on several. In each case we use the same architecture and objective, and simply train on different data.

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.

Our result (c) Application: Edit object appearance (b) Application: Change label types (a) Synthesized resultFigure 1: We propose a generative adversarial framework for synthesizing 2048 × 1024 images from semantic label maps (lower left corner in (a)). Compared to previous work [5], our results express more natural textures and details. (b) We can change labels in the original label map to create new scenes, like replacing trees with buildings. (c) Our framework also allows a user to edit the appearance of individual objects in the scene, e.g. changing the color of a car or the texture of a road. Please visit our website for more side-by-side comparisons as well as interactive editing demos.

Conditional Generative Adversarial Networks (GANs) for cross-domain image-to-image translation have made much progress recently [7,8,21,12,4,18]. Depending on the task complexity, thousands to millions of labeled image pairs are needed to train a conditional GAN. However, human labeling is expensive, even impractical, and large quantities of data may not always be available. Inspired by dual learning from natural language translation [23], we develop a novel dual-GAN mechanism, which enables image translators to be trained from two sets of unlabeled images from two domains. In our architecture, the primal GAN learns to translate images from domain U to those in domain V , while the dual GAN learns to invert the task. The closed loop made by the primal and dual tasks allows images from either domain to be translated and then reconstructed. Hence a loss function that accounts for the reconstruction error of images can be used to train the translators. Experiments on multiple image translation tasks with unlabeled data show considerable performance gain of Du-alGAN over a single GAN. For some tasks, DualGAN can even achieve comparable or slightly better results than conditional GAN trained on fully labeled data.

Given a grayscale photograph as input, this paper attacks the problem of hallucinating a plausible color version of the photograph. This problem is clearly underconstrained, so previous approaches have either relied on significant user interaction or resulted in desaturated colorizations. We propose a fully automatic approach that produces vibrant and realistic colorizations. We embrace the underlying uncertainty of the problem by posing it as a classification task and use class-rebalancing at training time to increase the diversity of colors in the result. The system is implemented as a feed-forward pass in a CNN at test time and is trained on over a million color images. We evaluate our algorithm using a "colorization Turing test," asking human participants to choose between a generated and ground truth color image. Our method successfully fools humans on 32% of the trials, significantly higher than previous methods. Moreover, we show that colorization can be a powerful pretext task for self-supervised feature learning, acting as a cross-channel encoder. This approach results in state-of-the-art performance on several feature learning benchmarks.

培训监督图像综合模型需要批评评论权来比较两个图像：结果的原始真相。然而，这种基本功能仍然是一个公开问题。流行的方法使用L1（平均绝对误差）丢失，或者在预先预留的深网络的像素或特征空间中。然而，我们观察到这些损失倾向于产生过度模糊和灰色的图像，以及其他技术，如GAN需要用于对抗这些伪影。在这项工作中，我们介绍了一种基于信息理论的方法来测量两个图像之间的相似性。我们认为，良好的重建应该具有较高的相互信息与地面真相。这种观点使得能够以对比的方式学习轻量级批评者以“校准”特征空间，使得相应的空间贴片的重建被置于擦除其他贴片。我们表明，当用作L1损耗的替代时，我们的配方立即提升输出图像的感知现实主义，有或没有额外的GaN丢失。

本文提出了有条件生成对抗性网络（CGANS）的两个重要贡献，以改善利用此架构的各种应用。第一个主要贡献是对CGANS的分析表明它们没有明确条件。特别地，将显示鉴别者和随后的Cgan不会自动学习输入之间的条件。第二种贡献是一种新方法，称为逆时针，该方法通过新颖的逆损失明确地模拟了对抗架构的两部分的条件，涉及培训鉴别者学习无条件（不利）示例。这导致了用于GANS（逆学习）的新型数据增强方法，其允许使用不利示例将发电机的搜索空间限制为条件输出。通过提出概率分布分析，进行广泛的实验以评估判别符的条件。与不同应用的CGAN架构的比较显示了众所周知的数据集的性能的显着改进，包括使用不同度量的不同度量的语义图像合成，图像分割，单眼深度预测和“单个标签” - 图像（FID） ），平均联盟（Miou）交叉口，根均线误差日志（RMSE日志）和统计上不同的箱数（NDB）。

生成的对抗网络（GANS）最近引入了执行图像到图像翻译的有效方法。这些模型可以应用于图像到图像到图像转换中的各种域而不改变任何参数。在本文中，我们调查并分析了八个图像到图像生成的对策网络：PIX2PX，Cyclegan，Cogan，Stargan，Munit，Stargan2，Da-Gan，以及自我关注GaN。这些模型中的每一个都呈现了最先进的结果，并引入了构建图像到图像的新技术。除了对模型的调查外，我们还调查了他们接受培训的18个数据集，并在其上进行了评估的9个指标。最后，我们在常见的一组指标和数据集中呈现6种这些模型的受控实验的结果。结果混合并显示，在某些数据集，任务和指标上，某些型号优于其他型号。本文的最后一部分讨论了这些结果并建立了未来研究领域。由于研究人员继续创新新的图像到图像GAN，因此他们非常重要地了解现有方法，数据集和指标。本文提供了全面的概述和讨论，以帮助构建此基础。

强大的模拟器高度降低了在培训和评估自动车辆时对真实测试的需求。数据驱动的模拟器蓬勃发展，最近有条件生成对冲网络（CGANS）的进步，提供高保真图像。主要挑战是在施加约束之后的同时合成光量造型图像。在这项工作中，我们建议通过重新思考鉴别者架构来提高所生成的图像的质量。重点是在给定对语义输入生成图像的问题类上，例如场景分段图或人体姿势。我们建立成功的CGAN模型，提出了一种新的语义感知鉴别器，更好地指导发电机。我们的目标是学习一个共享的潜在表示，编码足够的信息，共同进行语义分割，内容重建以及粗糙的粒度的对抗性推理。实现的改进是通用的，并且可以应用于任何条件图像合成的任何架构。我们展示了我们在场景，建筑和人类综合任务上的方法，跨越三个不同的数据集。代码可在https://github.com/vita-epfl/semdisc上获得。

In image-to-image translation, each patch in the output should reflect the content of the corresponding patch in the input, independent of domain. We propose a straightforward method for doing so -maximizing mutual information between the two, using a framework based on contrastive learning. The method encourages two elements (corresponding patches) to map to a similar point in a learned feature space, relative to other elements (other patches) in the dataset, referred to as negatives. We explore several critical design choices for making contrastive learning effective in the image synthesis setting. Notably, we use a multilayer, patch-based approach, rather than operate on entire images. Furthermore, we draw negatives from within the input image itself, rather than from the rest of the dataset. We demonstrate that our framework enables one-sided translation in the unpaired image-to-image translation setting, while improving quality and reducing training time. In addition, our method can even be extended to the training setting where each "domain" is only a single image.

图像转换是一类视觉和图形问题，其目标是学习输入图像和输出图像之间的映射，在深神网络的背景下迅速发展。在计算机视觉（CV）中，许多问题可以被视为图像转换任务，例如语义分割和样式转移。这些作品具有不同的主题和动机，使图像转换任务蓬勃发展。一些调查仅回顾有关样式转移或图像到图像翻译的研究，所有这些都只是图像转换的一个分支。但是，没有一项调查总结这些调查在我们最佳知识的统一框架中共同起作用。本文提出了一个新颖的学习框架，包括独立学习，指导学习和合作学习，称为IGC学习框架。我们讨论的图像转换主要涉及有关深神经网络的一般图像到图像翻译和样式转移。从这个框架的角度来看，我们回顾了这些子任务，并对各种情况进行统一的解释。我们根据相似的开发趋势对图像转换的相关子任务进行分类。此外，已经进行了实验以验证IGC学习的有效性。最后，讨论了新的研究方向和开放问题，以供将来的研究。

生成的对抗网络（GANS）已经促进了解决图像到图像转换问题的新方向。不同的GANS在目标函数中使用具有不同损耗的发电机和鉴别器网络。仍然存在差距来填补所生成的图像的质量并靠近地面真理图像。在这项工作中，我们介绍了一个名为循环辨别生成的对抗网络（CDGAN）的新的图像到图像转换网络，填补了上述空白。除了加速本的原始架构之外，所提出的CDGAN通过结合循环图像的附加鉴别器网络来产生高质量和更现实的图像。所提出的CDGAN在三个图像到图像转换数据集上进行测试。分析了定量和定性结果，并与最先进的方法进行了比较。在三个基线图像到图像转换数据集中，所提出的CDGAN方法优于最先进的方法。该代码可在https://github.com/kishankancharagunta/cdgan获得。

草图是一种从个人的创造性角度传达视觉场景的媒介。添加颜色基本上增强了草图的总体表征。本文提出了通过利用轮廓绘制数据集来模仿人绘制着色草图的两种方法。我们的第一个方法通过应用k-means颜色聚类辅助的图像处理技术来呈现彩色的轮廓草图。第二种方法使用生成的对抗性网络来开发一个可以从先前未观察到的图像生成彩色草图的模型。我们评估通过定量和定性评估获得的结果。

我们建议使用单个图像进行面部表达到表达翻译的简单而强大的地标引导的生成对抗网络（Landmarkgan），这在计算机视觉中是一项重要且具有挑战性的任务，因为表达到表达的翻译是非 - 线性和非对准问题。此外，由于图像中的对象可以具有任意的姿势，大小，位置，背景和自我观念，因此需要在输入图像和输出图像之间有一个高级的语义理解。为了解决这个问题，我们建议明确利用面部地标信息。由于这是一个具有挑战性的问题，我们将其分为两个子任务，（i）类别引导的地标生成，以及（ii）具有里程碑意义的指导表达式对表达的翻译。两项子任务以端到端的方式进行了培训，旨在享受产生的地标和表情的相互改善的好处。与当前的按键指导的方法相比，提议的Landmarkgan只需要单个面部图像即可产生各种表达式。四个公共数据集的广泛实验结果表明，与仅使用单个图像的最先进方法相比，所提出的Landmarkgan获得了更好的结果。该代码可从https://github.com/ha0tang/landmarkgan获得。

Random samples from a single image Single training image Figure 1: Image generation learned from a single training image. We propose SinGAN-a new unconditional generative model trained on a single natural image. Our model learns the image's patch statistics across multiple scales, using a dedicated multi-scale adversarial training scheme; it can then be used to generate new realistic image samples that preserve the original patch distribution while creating new object configurations and structures.

在没有人为干预的图像自动色彩上是在机器学习界的兴趣中的一个短暂的时间。分配颜色到图像是一个非常令人虐待的问题，因为它具有非常高的自由度的先天性;给定图像，通常没有单一的颜色组合是正确的。除了着色之外，图像重建中的另一个问题是单图像超分辨率，其旨在将低分辨率图像转换为更高的分辨率。该研究旨在通过专注于图像的非常特定的图像，即天文图像，并使用生成的对抗网络（GAN）来提供自动化方法。我们探索两种不同颜色空间，RGB和L * A *中各种型号的使用。我们使用传输学习，由于小数据集，使用预先训练的Reset-18作为骨干，即U-Net的编码器，进一步微调。该模型产生视觉上有吸引力的图像，其在原始图像中不存在的这些结果中呈现的高分辨率高分辨率，着色数据。我们通过使用所有通道的每个颜色空间中的距离度量（例如L1距离和L2距离）评估GAN来提供我们的结果，以提供比较分析。我们使用Frechet Inception距离（FID）将生成的图像的分布与实际图像的分布进行比较，以评估模型的性能。

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.

We present an unsupervised visual feature learning algorithm driven by context-based pixel prediction. By analogy with auto-encoders, we propose Context Encoders -a convolutional neural network trained to generate the contents of an arbitrary image region conditioned on its surroundings. In order to succeed at this task, context encoders need to both understand the content of the entire image, as well as produce a plausible hypothesis for the missing part(s). When training context encoders, we have experimented with both a standard pixel-wise reconstruction loss, as well as a reconstruction plus an adversarial loss. The latter produces much sharper results because it can better handle multiple modes in the output. We found that a context encoder learns a representation that captures not just appearance but also the semantics of visual structures. We quantitatively demonstrate the effectiveness of our learned features for CNN pre-training on classification, detection, and segmentation tasks. Furthermore, context encoders can be used for semantic inpainting tasks, either stand-alone or as initialization for non-parametric methods.