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.
translated by 谷歌翻译
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.
translated by 谷歌翻译
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.
translated by 谷歌翻译
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.
translated by 谷歌翻译
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.
translated by 谷歌翻译
Depth estimation is usually ill-posed and ambiguous for monocular camera-based 3D multi-person pose estimation. Since LiDAR can capture accurate depth information in long-range scenes, it can benefit both the global localization of individuals and the 3D pose estimation by providing rich geometry features. Motivated by this, we propose a monocular camera and single LiDAR-based method for 3D multi-person pose estimation in large-scale scenes, which is easy to deploy and insensitive to light. Specifically, we design an effective fusion strategy to take advantage of multi-modal input data, including images and point cloud, and make full use of temporal information to guide the network to learn natural and coherent human motions. Without relying on any 3D pose annotations, our method exploits the inherent geometry constraints of point cloud for self-supervision and utilizes 2D keypoints on images for weak supervision. Extensive experiments on public datasets and our newly collected dataset demonstrate the superiority and generalization capability of our proposed method.
translated by 谷歌翻译
Neural Radiance Field (NeRF) has widely received attention in Sparse-View Computed Tomography (SVCT) reconstruction tasks as a self-supervised deep learning framework. NeRF-based SVCT methods represent the desired CT image as a continuous function of spatial coordinates and train a Multi-Layer Perceptron (MLP) to learn the function by minimizing loss on the SV sinogram. Benefiting from the continuous representation provided by NeRF, the high-quality CT image can be reconstructed. However, existing NeRF-based SVCT methods strictly suppose there is completely no relative motion during the CT acquisition because they require \textit{accurate} projection poses to model the X-rays that scan the SV sinogram. Therefore, these methods suffer from severe performance drops for real SVCT imaging with motion. In this work, we propose a self-calibrating neural field to recover the artifacts-free image from the rigid motion-corrupted SV sinogram without using any external data. Specifically, we parametrize the inaccurate projection poses caused by rigid motion as trainable variables and then jointly optimize these pose variables and the MLP. We conduct numerical experiments on a public CT image dataset. The results indicate our model significantly outperforms two representative NeRF-based methods for SVCT reconstruction tasks with four different levels of rigid motion.
translated by 谷歌翻译
最近,我们看到了照片真实的人类建模和渲染的神经进展取得的巨大进展。但是,将它们集成到现有的下游应用程序中的现有网络管道中仍然具有挑战性。在本文中,我们提出了一种全面的神经方法,用于从密集的多视频视频中对人类表演进行高质量重建,压缩和渲染。我们的核心直觉是用一系列高效的神经技术桥接传统的动画网格工作流程。我们首先引入一个神经表面重建器,以在几分钟内进行高质量的表面产生。它与多分辨率哈希编码的截短签名距离场(TSDF)的隐式体积渲染相结合。我们进一步提出了一个混合神经跟踪器来生成动画网格,该网格将明确的非刚性跟踪与自我监督框架中的隐式动态变形结合在一起。前者将粗糙的翘曲返回到规范空间中,而后者隐含的一个隐含物进一步预测了使用4D哈希编码的位移,如我们的重建器中。然后,我们使用获得的动画网格讨论渲染方案,从动态纹理到各种带宽设置下的Lumigraph渲染。为了在质量和带宽之间取得复杂的平衡,我们通过首先渲染6个虚拟视图来涵盖表演者,然后进行闭塞感知的神经纹理融合,提出一个分层解决方案。我们证明了我们方法在各种平台上的各种基于网格的应用程序和照片真实的自由观看体验中的功效,即,通过移动AR插入虚拟人类的表演,或通过移动AR插入真实环境,或带有VR头戴式的人才表演。
translated by 谷歌翻译
近年来,由于其在数字人物,角色产生和动画中的广泛应用,人们对3D人脸建模的兴趣越来越大。现有方法压倒性地强调了对面部的外部形状,质地和皮肤特性建模,而忽略了内部骨骼结构和外观之间的固有相关性。在本文中,我们使用学习的参数面部发电机提出了雕塑家,具有骨骼一致性的3D面部创作,旨在通过混合参数形态表示轻松地创建解剖上正确和视觉上令人信服的面部模型。雕塑家的核心是露西(Lucy),这是与整形外科医生合作的第一个大型形状面部脸部数据集。我们的Lucy数据集以最古老的人类祖先之一的化石命名,其中包含正牙手术前后全人头的高质量计算机断层扫描(CT)扫描,这对于评估手术结果至关重要。露西(Lucy)由144次扫描,分别对72名受试者(31名男性和41名女性)组成,其中每个受试者进行了两次CT扫描,并在恐惧后手术中进行了两次CT扫描。根据我们的Lucy数据集,我们学习了一个新颖的骨骼一致的参数面部发电机雕塑家,它可以创建独特而细微的面部特征,以帮助定义角色,同时保持生理声音。我们的雕塑家通过将3D脸的描绘成形状混合形状,姿势混合形状和面部表达混合形状,共同在统一数据驱动的框架下共同建模头骨,面部几何形状和面部外观。与现有方法相比,雕塑家在面部生成任务中保留了解剖学正确性和视觉现实主义。最后,我们展示了雕塑家在以前看不见的各种花式应用中的鲁棒性和有效性。
translated by 谷歌翻译
在目前的工作中,我们提出了一个自制的坐标投影网络(范围),以通过解决逆断层扫描成像问题来从单个SV正弦图中重建无伪像的CT图像。与使用隐式神经代表网络(INR)解决类似问题的最新相关工作相比,我们的基本贡献是一种有效而简单的重新注射策略,可以将层析成像图像重建质量推向监督的深度学习CT重建工作。提出的策略是受线性代数与反问题之间的简单关系的启发。为了求解未确定的线性方程式系统,我们首先引入INR以通过图像连续性之前限制解决方案空间并实现粗糙解决方案。其次,我们建议生成一个密集的视图正式图,以改善线性方程系统的等级并产生更稳定的CT图像解决方案空间。我们的实验结果表明,重新投影策略显着提高了图像重建质量(至少为PSNR的+3 dB)。此外,我们将最近的哈希编码集成到我们的范围模型中,这极大地加速了模型培训。最后,我们评估并联和风扇X射线梁SVCT重建任务的范围。实验结果表明,所提出的范围模型优于两种基于INR的方法和两种受欢迎的监督DL方法。
translated by 谷歌翻译