Human modeling and relighting are two fundamental problems in computer vision and graphics, where high-quality datasets can largely facilitate related research. However, most existing human datasets only provide multi-view human images captured under the same illumination. Although valuable for modeling tasks, they are not readily used in relighting problems. To promote research in both fields, in this paper, we present UltraStage, a new 3D human dataset that contains more than 2K high-quality human assets captured under both multi-view and multi-illumination settings. Specifically, for each example, we provide 32 surrounding views illuminated with one white light and two gradient illuminations. In addition to regular multi-view images, gradient illuminations help recover detailed surface normal and spatially-varying material maps, enabling various relighting applications. Inspired by recent advances in neural representation, we further interpret each example into a neural human asset which allows novel view synthesis under arbitrary lighting conditions. We show our neural human assets can achieve extremely high capture performance and are capable of representing fine details such as facial wrinkles and cloth folds. We also validate UltraStage in single image relighting tasks, training neural networks with virtual relighted data from neural assets and demonstrating realistic rendering improvements over prior arts. UltraStage will be publicly available to the community to stimulate significant future developments in various human modeling and rendering tasks.
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我们人类正在进入虚拟时代,确实想将动物带到虚拟世界中。然而,计算机生成的(CGI)毛茸茸的动物受到乏味的离线渲染的限制,更不用说交互式运动控制了。在本文中,我们提出了Artemis,这是一种新型的神经建模和渲染管道,用于生成具有外观和运动合成的清晰神经宠物。我们的Artemis可以实现互动运动控制,实时动画和毛茸茸的动物的照片真实渲染。我们的Artemis的核心是神经生成的(NGI)动物引擎,该动物发动机采用了有效的基于OCTREE的动物动画和毛皮渲染的代表。然后,该动画等同于基于显式骨骼翘曲的体素级变形。我们进一步使用快速的OCTREE索引和有效的体积渲染方案来生成外观和密度特征地图。最后,我们提出了一个新颖的阴影网络,以在外观和密度特征图中生成外观和不透明度的高保真细节。对于Artemis中的运动控制模块,我们将最新动物运动捕获方法与最近的神经特征控制方案相结合。我们引入了一种有效的优化方案,以重建由多视图RGB和Vicon相机阵列捕获的真实动物的骨骼运动。我们将所有捕获的运动馈送到神经角色控制方案中,以生成具有运动样式的抽象控制信号。我们将Artemis进一步整合到支持VR耳机的现有引擎中,提供了前所未有的沉浸式体验,用户可以与各种具有生动动作和光真实外观的虚拟动物进行紧密互动。我们可以通过https://haiminluo.github.io/publication/artemis/提供我们的Artemis模型和动态毛茸茸的动物数据集。
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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.
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照片逼真的面部视频肖像重演益处虚拟生产和众多VR / AR经验。由于肖像应该保持高现实主义和与目标环境的一致性,任务仍然具有挑战性。在本文中,我们介绍了一种可靠的神经视频肖像,同步的致密和再生方案,其将头部姿势和面部表达从源actor传送到具有任意新的背景和照明条件的目标演员的肖像视频。我们的方法结合了4D反射场学习,基于模型的面部性能捕获和目标感知神经渲染。具体地,我们采用渲染到视频翻译网络首先从混合面部性能捕获结果中合成高质量的OLAT镜片和alpha锍。然后,我们设计了一个语义感知的面部归一化方案,以实现可靠的显式控制以及多帧多任务学习策略,以同时编码内容,分割和时间信息以获得高质量的反射场推断。在培训之后,我们的方法进一步实现了目标表演者的照片现实和可控的视频肖像编辑。通过将相同的混合面部捕获和归一化方案应用于源视频输入,可以获得可靠的面部姿势和表达编辑,而我们的显式alpha和Olat输出使高质量的依据和背景编辑能够实现。凭借实现同步致密和再生的能力,我们能够改善各种虚拟生产和视频重写应用程序的现实主义。
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在实际应用中,通常可以获得较小的数据集。目前,机器学习的大多数实际应用都使用基于大数据的经典模型来解决小型数据集的问题。但是,深度神经网络模型具有复杂的结构,巨大的模型参数和培训需要更高级的设备,这给应用程序带来了一定的困难。因此,本文提出了工会卷积的概念,设计了具有浅网络结构的光线深网模型联合网络,并适应了小型数据集。该模型将卷积网络单元与相同输入的不同组合结合在一起,形成联合模块。每个联合模块等效于卷积层。 3个模块之间的串行输入和输出构成了“ 3层”神经网络。每个联合模块的输出融合并添加为最后一个卷积层的输入,以形成具有4层网络结构的复杂网络。它解决了深层网络模型网络太深并且传输路径太长的问题,这会导致基础信息传输的丢失。由于模型的模型参数较少,通道较少,因此可以更好地适应小型数据集。它解决了一个问题,即深网模型容易过度培训小型数据集。使用公共数据集CIFAR10和17Flowers进行多分类实验。实验表明,联合网络模型可以在大型数据集和小数据集的分类中表现良好。它在日常应用程序方案中具有很高的实践价值。该模型代码发表在https://github.com/yeaso/union-net上
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Blind image quality assessment (BIQA) remains challenging due to the diversity of distortion and image content variation, which complicate the distortion patterns crossing different scales and aggravate the difficulty of the regression problem for BIQA. However, existing BIQA methods often fail to consider multi-scale distortion patterns and image content, and little research has been done on learning strategies to make the regression model produce better performance. In this paper, we propose a simple yet effective Progressive Multi-Task Image Quality Assessment (PMT-IQA) model, which contains a multi-scale feature extraction module (MS) and a progressive multi-task learning module (PMT), to help the model learn complex distortion patterns and better optimize the regression issue to align with the law of human learning process from easy to hard. To verify the effectiveness of the proposed PMT-IQA model, we conduct experiments on four widely used public datasets, and the experimental results indicate that the performance of PMT-IQA is superior to the comparison approaches, and both MS and PMT modules improve the model's performance.
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In the scenario of black-box adversarial attack, the target model's parameters are unknown, and the attacker aims to find a successful adversarial perturbation based on query feedback under a query budget. Due to the limited feedback information, existing query-based black-box attack methods often require many queries for attacking each benign example. To reduce query cost, we propose to utilize the feedback information across historical attacks, dubbed example-level adversarial transferability. Specifically, by treating the attack on each benign example as one task, we develop a meta-learning framework by training a meta-generator to produce perturbations conditioned on benign examples. When attacking a new benign example, the meta generator can be quickly fine-tuned based on the feedback information of the new task as well as a few historical attacks to produce effective perturbations. Moreover, since the meta-train procedure consumes many queries to learn a generalizable generator, we utilize model-level adversarial transferability to train the meta-generator on a white-box surrogate model, then transfer it to help the attack against the target model. The proposed framework with the two types of adversarial transferability can be naturally combined with any off-the-shelf query-based attack methods to boost their performance, which is verified by extensive experiments.
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Humans constantly interact with objects in daily life tasks. Capturing such processes and subsequently conducting visual inferences from a fixed viewpoint suffers from occlusions, shape and texture ambiguities, motions, etc. To mitigate the problem, it is essential to build a training dataset that captures free-viewpoint interactions. We construct a dense multi-view dome to acquire a complex human object interaction dataset, named HODome, that consists of $\sim$75M frames on 10 subjects interacting with 23 objects. To process the HODome dataset, we develop NeuralDome, a layer-wise neural processing pipeline tailored for multi-view video inputs to conduct accurate tracking, geometry reconstruction and free-view rendering, for both human subjects and objects. Extensive experiments on the HODome dataset demonstrate the effectiveness of NeuralDome on a variety of inference, modeling, and rendering tasks. Both the dataset and the NeuralDome tools will be disseminated to the community for further development.
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We study a challenging task, conditional human motion generation, which produces plausible human motion sequences according to various conditional inputs, such as action classes or textual descriptors. Since human motions are highly diverse and have a property of quite different distribution from conditional modalities, such as textual descriptors in natural languages, it is hard to learn a probabilistic mapping from the desired conditional modality to the human motion sequences. Besides, the raw motion data from the motion capture system might be redundant in sequences and contain noises; directly modeling the joint distribution over the raw motion sequences and conditional modalities would need a heavy computational overhead and might result in artifacts introduced by the captured noises. To learn a better representation of the various human motion sequences, we first design a powerful Variational AutoEncoder (VAE) and arrive at a representative and low-dimensional latent code for a human motion sequence. Then, instead of using a diffusion model to establish the connections between the raw motion sequences and the conditional inputs, we perform a diffusion process on the motion latent space. Our proposed Motion Latent-based Diffusion model (MLD) could produce vivid motion sequences conforming to the given conditional inputs and substantially reduce the computational overhead in both the training and inference stages. Extensive experiments on various human motion generation tasks demonstrate that our MLD achieves significant improvements over the state-of-the-art methods among extensive human motion generation tasks, with two orders of magnitude faster than previous diffusion models on raw motion sequences.
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Most existing scene text detectors require large-scale training data which cannot scale well due to two major factors: 1) scene text images often have domain-specific distributions; 2) collecting large-scale annotated scene text images is laborious. We study domain adaptive scene text detection, a largely neglected yet very meaningful task that aims for optimal transfer of labelled scene text images while handling unlabelled images in various new domains. Specifically, we design SCAST, a subcategory-aware self-training technique that mitigates the network overfitting and noisy pseudo labels in domain adaptive scene text detection effectively. SCAST consists of two novel designs. For labelled source data, it introduces pseudo subcategories for both foreground texts and background stuff which helps train more generalizable source models with multi-class detection objectives. For unlabelled target data, it mitigates the network overfitting by co-regularizing the binary and subcategory classifiers trained in the source domain. Extensive experiments show that SCAST achieves superior detection performance consistently across multiple public benchmarks, and it also generalizes well to other domain adaptive detection tasks such as vehicle detection.
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