With recent progress in graphics, it has become more tractable to train models on synthetic images, potentially avoiding the need for expensive annotations. However, learning from synthetic images may not achieve the desired performance due to a gap between synthetic and real image distributions. To reduce this gap, we propose Simulated+Unsupervised (S+U) learning, where the task is to learn a model to improve the realism of a simulator's output using unlabeled real data, while preserving the annotation information from the simulator. We develop a method for S+U learning that uses an adversarial network similar to Generative Adversarial Networks (GANs), but with synthetic images as inputs instead of random vectors. We make several key modifications to the standard GAN algorithm to preserve annotations, avoid artifacts, and stabilize training: (i) a 'self-regularization' term, (ii) a local adversarial loss, and (iii) updating the discriminator using a history of refined images. We show that this enables generation of highly realistic images, which we demonstrate both qualitatively and with a user study. We quantitatively evaluate the generated images by training models for gaze estimation and hand pose estimation. We show a significant improvement over using synthetic images, and achieve state-of-the-art results on the MPIIGaze dataset without any labeled real data.
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Collecting well-annotated image datasets to train modern machine learning algorithms is prohibitively expensive for many tasks. An appealing alternative is to render synthetic data where ground-truth annotations are generated automatically. Unfortunately, models trained purely on rendered images often fail to generalize to real images. To address this shortcoming, prior work introduced unsupervised domain adaptation algorithms that attempt to map representations between the two domains or learn to extract features that are domain-invariant. In this work, we present a new approach that learns, in an unsupervised manner, a transformation in the pixel space from one domain to the other. Our generative adversarial network (GAN)-based model adapts source-domain images to appear as if drawn from the target domain. Our approach not only produces plausible samples, but also outperforms the state-of-the-art on a number of unsupervised domain adaptation scenarios by large margins. Finally, we demonstrate that the adaptation process generalizes to object classes unseen during training.
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鉴于一个人的肖像图像和目标照明的环境图,肖像重新旨在重新刷新图像中的人,就好像该人出现在具有目标照明的环境中一样。为了获得高质量的结果,最近的方法依靠深度学习。一种有效的方法是用高保真输入输出对的高保真数据集监督对深神经网络的培训,并以光阶段捕获。但是,获取此类数据需要昂贵的特殊捕获钻机和耗时的工作,从而限制了对少数机智的实验室的访问。为了解决限制,我们提出了一种新方法,该方法可以与最新的(SOTA)重新确定方法相提并论,而无需光阶段。我们的方法基于这样的意识到,肖像图像的成功重新重新取决于两个条件。首先,该方法需要模仿基于物理的重新考虑的行为。其次,输出必须是逼真的。为了满足第一个条件,我们建议通过通过虚拟光阶段生成的训练数据来训练重新网络,该培训数据在不同的环境图下对各种3D合成人体进行了基于物理的渲染。为了满足第二种条件,我们开发了一种新型的合成对真实方法,以将光真实主义带入重新定向网络输出。除了获得SOTA结果外,我们的方法还提供了与先前方法相比的几个优点,包括可控的眼镜和更暂时的结果以重新欣赏视频。
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Current state-of-the-art segmentation techniques for ocular images are critically dependent on large-scale annotated datasets, which are labor-intensive to gather and often raise privacy concerns. In this paper, we present a novel framework, called BiOcularGAN, capable of generating synthetic large-scale datasets of photorealistic (visible light and near-infrared) ocular images, together with corresponding segmentation labels to address these issues. At its core, the framework relies on a novel Dual-Branch StyleGAN2 (DB-StyleGAN2) model that facilitates bimodal image generation, and a Semantic Mask Generator (SMG) component that produces semantic annotations by exploiting latent features of the DB-StyleGAN2 model. We evaluate BiOcularGAN through extensive experiments across five diverse ocular datasets and analyze the effects of bimodal data generation on image quality and the produced annotations. Our experimental results show that BiOcularGAN is able to produce high-quality matching bimodal images and annotations (with minimal manual intervention) that can be used to train highly competitive (deep) segmentation models (in a privacy aware-manner) that perform well across multiple real-world datasets. The source code for the BiOcularGAN framework is publicly available at https://github.com/dariant/BiOcularGAN.
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深度学习模型在机器人技术中的有用性在很大程度上取决于培训数据的可用性。培训数据的手动注释通常是不可行的。合成数据是可行的替代方法,但遭受了域间隙。我们提出了一种多步方法,以获取训练数据而无需手动注释:从3D对象网格中,我们使用现代合成管道生成图像。我们利用一种最先进的图像到图像翻译方法来使合成图像适应真实域,以学习的方式最大程度地减少域间隙。翻译网络是从未配对的图像中训练的,即仅需要未经通知的真实图像集合。然后,生成和精致的图像可用于训练深度学习模型以完成特定任务。我们还建议并评估翻译方法的扩展,以进一步提高性能,例如基于补丁的训练,从而缩短了训练时间并增加了全球一致性。我们评估我们的方法并证明其在两个机器人数据集上的有效性。我们终于深入了解了博学的改进操作。
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深度神经网络在人类分析中已经普遍存在,增强了应用的性能,例如生物识别识别,动作识别以及人重新识别。但是,此类网络的性能通过可用的培训数据缩放。在人类分析中,对大规模数据集的需求构成了严重的挑战,因为数据收集乏味,廉价,昂贵,并且必须遵守数据保护法。当前的研究研究了\ textit {合成数据}的生成,作为在现场收集真实数据的有效且具有隐私性的替代方案。这项调查介绍了基本定义和方法,在生成和采用合成数据进行人类分析时必不可少。我们进行了一项调查,总结了当前的最新方法以及使用合成数据的主要好处。我们还提供了公开可用的合成数据集和生成模型的概述。最后,我们讨论了该领域的局限性以及开放研究问题。这项调查旨在为人类分析领域的研究人员和从业人员提供。
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我们提出了一条新型的神经管道Msgazenet,该管道通过通过多发射框架利用眼睛解剖学信息来学习凝视的表示。我们提出的解决方案包括两个组件,首先是一个用于隔离解剖眼区域的网络,以及第二个用于多发达凝视估计的网络。眼睛区域的隔离是通过U-NET样式网络进行的,我们使用合成数据集训练该网络,该数据集包含可见眼球和虹膜区域的眼睛区域掩模。此阶段使用的合成数据集是一个由60,000张眼睛图像组成的新数据集,我们使用眼视线模拟器Unityeyes创建。然后将眼睛区域隔离网络转移到真实域,以生成真实世界图像的面具。为了成功进行转移,我们在训练过程中利用域随机化,这允许合成图像从较大的差异中受益,并在类似于伪影的增强的帮助下从更大的差异中受益。然后,生成的眼睛区域掩模与原始眼睛图像一起用作我们凝视估计网络的多式输入。我们在三个基准凝视估计数据集(Mpiigaze,Eyediap和Utmultiview)上评估框架,在那里我们通过分别获得7.57%和1.85%的性能,在Eyediap和Utmultiview数据集上设置了新的最新技术Mpiigaze的竞争性能。我们还研究了方法在数据中的噪声方面的鲁棒性,并证明我们的模型对噪声数据不太敏感。最后,我们执行各种实验,包括消融研究,以评估解决方案中不同组件和设计选择的贡献。
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凝视和头部姿势估计模型的鲁棒性高度取决于标记的数据量。最近,生成建模在生成照片现实图像方面表现出了出色的结果,这可以减轻对标记数据的需求。但是,在新领域采用这种生成模型,同时保持其对不同图像属性的细粒度控制的能力,例如,凝视和头部姿势方向,是一个挑战性的问题。本文提出了Cuda-GHR,这是一种无监督的域适应框架,可以对凝视和头部姿势方向进行细粒度的控制,同时保留该人的外观相关因素。我们的框架同时学会了通过利用富含标签的源域和未标记的目标域来适应新的域和删除图像属性,例如外观,凝视方向和头部方向。基准测试数据集的广泛实验表明,所提出的方法在定量和定性评估上都可以胜过最先进的技术。此外,我们表明目标域中生成的图像标签对有效地传递知识并提高下游任务的性能。
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语义分割在广泛的计算机视觉应用中起着基本作用,提供了全球对图像​​的理解的关键信息。然而,最先进的模型依赖于大量的注释样本,其比在诸如图像分类的任务中获得更昂贵的昂贵的样本。由于未标记的数据替代地获得更便宜,因此无监督的域适应达到了语义分割社区的广泛成功并不令人惊讶。本调查致力于总结这一令人难以置信的快速增长的领域的五年,这包含了语义细分本身的重要性,以及将分段模型适应新环境的关键需求。我们提出了最重要的语义分割方法;我们对语义分割的域适应技术提供了全面的调查;我们揭示了多域学习,域泛化,测试时间适应或无源域适应等较新的趋势;我们通过描述在语义细分研究中最广泛使用的数据集和基准测试来结束本调查。我们希望本调查将在学术界和工业中提供具有全面参考指导的研究人员,并有助于他们培养现场的新研究方向。
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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。
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作为许多自主驾驶和机器人活动的基本组成部分,如自我运动估计,障碍避免和场景理解,单眼深度估计(MDE)引起了计算机视觉和机器人社区的极大关注。在过去的几十年中,已经开发了大量方法。然而,据我们所知,对MDE没有全面调查。本文旨在通过审查1970年至2021年之间发布的197个相关条款来弥补这一差距。特别是,我们为涵盖各种方法的MDE提供了全面的调查,介绍了流行的绩效评估指标并汇总公开的数据集。我们还总结了一些代表方法的可用开源实现,并比较了他们的表演。此外,我们在一些重要的机器人任务中审查了MDE的应用。最后,我们通过展示一些有希望的未来研究方向来结束本文。预计本调查有助于读者浏览该研究领域。
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Image-generating machine learning models are typically trained with loss functions based on distance in the image space. This often leads to over-smoothed results. We propose a class of loss functions, which we call deep perceptual similarity metrics (DeePSiM), that mitigate this problem. Instead of computing distances in the image space, we compute distances between image features extracted by deep neural networks. This metric better reflects perceptually similarity of images and thus leads to better results. We show three applications: autoencoder training, a modification of a variational autoencoder, and inversion of deep convolutional networks. In all cases, the generated images look sharp and resemble natural images.
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Domain adaptation is critical for success in new, unseen environments. Adversarial adaptation models applied in feature spaces discover domain invariant representations, but are difficult to visualize and sometimes fail to capture pixel-level and low-level domain shifts. Recent work has shown that generative adversarial networks combined with cycle-consistency constraints are surprisingly effective at mapping images between domains, even without the use of aligned image pairs. We propose a novel discriminatively-trained Cycle-Consistent Adversarial Domain Adaptation model. CyCADA adapts representations at both the pixel-level and feature-level, enforces cycle-consistency while leveraging a task loss, and does not require aligned pairs. Our model can be applied in a variety of visual recognition and prediction settings. We show new state-of-the-art results across multiple adaptation tasks, including digit classification and semantic segmentation of road scenes demonstrating transfer from synthetic to real world domains.
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Single image super-resolution is the task of inferring a high-resolution image from a single low-resolution input. Traditionally, the performance of algorithms for this task is measured using pixel-wise reconstruction measures such as peak signal-to-noise ratio (PSNR) which have been shown to correlate poorly with the human perception of image quality. As a result, algorithms minimizing these metrics tend to produce over-smoothed images that lack highfrequency textures and do not look natural despite yielding high PSNR values.We propose a novel application of automated texture synthesis in combination with a perceptual loss focusing on creating realistic textures rather than optimizing for a pixelaccurate reproduction of ground truth images during training. By using feed-forward fully convolutional neural networks in an adversarial training setting, we achieve a significant boost in image quality at high magnification ratios. Extensive experiments on a number of datasets show the effectiveness of our approach, yielding state-of-the-art results in both quantitative and qualitative benchmarks.
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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.
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深度学习的关键批评之一是,需要大量昂贵且难以获得的训练数据,以便培训具有高性能和良好的概率功能的模型。专注于通过场景坐标回归(SCR)的单眼摄像机姿势估计的任务,我们描述了一种新的方法,用于相机姿势估计(舞蹈)网络的域改编,这使得培训模型无需访问目标任务上的任何标签。舞蹈需要未标记的图像(没有已知的姿势,订购或场景坐标标签)和空间的3D表示(例如,扫描点云),这两者都可以使用现成的商品硬件最少的努力来捕获。舞蹈渲染从3D模型标记的合成图像,通过应用无监督的图像级域适应技术(未配对图像到图像转换)来桥接合成和实图像之间的不可避免的域间隙。在实际图像上进行测试时,舞蹈培训的SCR模型在成本的一小部分中对其完全监督的对应物(在两种情况下使用PNP-RANSAC进行最终姿势估算的情况下)进行了相当的性能。我们的代码和数据集可以在https://github.com/jacklangerman/dance获得
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Estimating human pose, shape, and motion from images and videos are fundamental challenges with many applications. Recent advances in 2D human pose estimation use large amounts of manually-labeled training data for learning convolutional neural networks (CNNs). Such data is time consuming to acquire and difficult to extend. Moreover, manual labeling of 3D pose, depth and motion is impractical. In this work we present SURREAL (Synthetic hUmans foR REAL tasks): a new large-scale dataset with synthetically-generated but realistic images of people rendered from 3D sequences of human motion capture data. We generate more than 6 million frames together with ground truth pose, depth maps, and segmentation masks. We show that CNNs trained on our synthetic dataset allow for accurate human depth estimation and human part segmentation in real RGB images. Our results and the new dataset open up new possibilities for advancing person analysis using cheap and large-scale synthetic data.
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Deep learning techniques have made considerable progress in image inpainting, restoration, and reconstruction in the last few years. Image outpainting, also known as image extrapolation, lacks attention and practical approaches to be fulfilled, owing to difficulties caused by large-scale area loss and less legitimate neighboring information. These difficulties have made outpainted images handled by most of the existing models unrealistic to human eyes and spatially inconsistent. When upsampling through deconvolution to generate fake content, the naive generation methods may lead to results lacking high-frequency details and structural authenticity. Therefore, as our novelties to handle image outpainting problems, we introduce structural prior as a condition to optimize the generation quality and a new semantic embedding term to enhance perceptual sanity. we propose a deep learning method based on Generative Adversarial Network (GAN) and condition edges as structural prior in order to assist the generation. We use a multi-phase adversarial training scheme that comprises edge inference training, contents inpainting training, and joint training. The newly added semantic embedding loss is proved effective in practice.
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生成的对抗网络(GANS)已经实现了图像生成的照片逼真品质。但是,如何最好地控制图像内容仍然是一个开放的挑战。我们介绍了莱特基照片,这是一个两级GaN,它在古典GAN目标上训练了训练,在一组空间关键点上有内部调节。这些关键点具有相关的外观嵌入,分别控制生成对象的位置和样式及其部件。我们使用合适的网络架构和培训方案地址的一个主要困难在没有领域知识和监督信号的情况下将图像解开到空间和外观因素中。我们展示了莱特基点提供可解释的潜在空间,可用于通过重新定位和交换Keypoint Embedding来重新安排生成的图像,例如通过组合来自不同图像的眼睛,鼻子和嘴巴来产生肖像。此外,关键点和匹配图像的显式生成启用了一种用于无监督的关键点检测的新的GaN的方法。
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The main contribution of this paper is a simple semisupervised pipeline that only uses the original training set without collecting extra data. It is challenging in 1) how to obtain more training data only from the training set and 2) how to use the newly generated data. In this work, the generative adversarial network (GAN) is used to generate unlabeled samples. We propose the label smoothing regularization for outliers (LSRO). This method assigns a uniform label distribution to the unlabeled images, which regularizes the supervised model and improves the baseline.We verify the proposed method on a practical problem: person re-identification (re-ID). This task aims to retrieve a query person from other cameras. We adopt the deep convolutional generative adversarial network (DCGAN) for sample generation, and a baseline convolutional neural network (CNN) for representation learning. Experiments show that adding the GAN-generated data effectively improves the discriminative ability of learned CNN embeddings. On three large-scale datasets, Market-1501, CUHK03 and DukeMTMC-reID, we obtain +4.37%, +1.6% and +2.46% improvement in rank-1 precision over the baseline CNN, respectively. We additionally apply the proposed method to fine-grained bird recognition and achieve a +0.6% improvement over a strong baseline. The code is available at https://github.com/layumi/Person-reID_GAN .
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