我们提出了一种学习方法，可以从单个视图开始生成自然场景的无界飞行视频，在该视图中，从单个照片集中学习了这种功能，而无需每个场景的相机姿势甚至多个视图。为了实现这一目标，我们提出了一种新颖的自我监督视图生成训练范式，在这里我们采样和渲染虚拟摄像头轨迹，包括循环轨迹，使我们的模型可以从单个视图集合中学习稳定的视图生成。在测试时，尽管在训练过程中从未见过视频，但我们的方法可以拍摄单个图像，并产生长的相机轨迹，包括数百个新视图，具有现实和多样化的内容。我们将我们的方法与最新的监督视图生成方法进行了比较，该方法需要摆姿势的多视频视频，并展示了卓越的性能和综合质量。

我们介绍了与给定单个图像的任意长相机轨迹相对应的长期视图的新面积视图的问题。这是一个具有挑战性的问题，远远超出了当前视图合成方法的能力，这在提出大型摄像机运动时快速退化。用于视频生成的方法也具有有限的生产长序列的能力，并且通常不适用于场景几何形状。我们采用混合方法，它以迭代`\ emph {render}，\ emph {refine}，\ emph {重复}'框架集成了几何和图像合成，允许在数百帧之后覆盖大距离的远程生成。我们的方法可以从一组单目的视频序列训练。我们提出了一个沿海场景的空中镜头数据集，并比较了我们最近的观看综合和有条件的视频生成基线的方法，表明它可以在与现有方法相比，在大型相机轨迹上产生更长的时间范围。项目页面https://infinite-nature.github.io/。

Figure 1: Our method can synthesize novel views in both space and time from a single monocular video of a dynamic scene. Here we show video results with various configurations of fixing and interpolating view and time (left), as well as a visualization of the recovered scene geometry (right). Please view with Adobe Acrobat or KDE Okular to see animations.

用于运动中的人类的新型视图综合是一个具有挑战性的计算机视觉问题，使得诸如自由视视频之类的应用。现有方法通常使用具有多个输入视图，3D监控或预训练模型的复杂设置，这些模型不会概括为新标识。旨在解决这些限制，我们提出了一种新颖的视图综合框架，以从单视图传感器捕获的任何人的看法生成现实渲染，其具有稀疏的RGB-D，类似于低成本深度摄像头，而没有参与者特定的楷模。我们提出了一种架构来学习由基于球体的神经渲染获得的小说视图中的密集功能，并使用全局上下文修复模型创建完整的渲染。此外，增强剂网络利用了整体保真度，即使在原始视图中的遮挡区域中也能够产生细节的清晰渲染。我们展示了我们的方法为单个稀疏RGB-D输入产生高质量的合成和真实人体演员的新颖视图。它概括了看不见的身份，新的姿势，忠实地重建面部表情。我们的方法优于现有人体观测合成方法，并且对不同水平的输入稀疏性具有稳健性。

A recent strand of work in view synthesis uses deep learning to generate multiplane images-a camera-centric, layered 3D representation-given two or more input images at known viewpoints. We apply this representation to singleview view synthesis, a problem which is more challenging but has potentially much wider application. Our method learns to predict a multiplane image directly from a single image input, and we introduce scale-invariant view synthesis for supervision, enabling us to train on online video. We show this approach is applicable to several different datasets, that it additionally generates reasonable depth maps, and that it learns to fill in content behind the edges of foreground objects in background layers.Project page at https://single-view-mpi.github.io/.

We study the problem of synthesizing immersive 3D indoor scenes from one or more images. Our aim is to generate high-resolution images and videos from novel viewpoints, including viewpoints that extrapolate far beyond the input images while maintaining 3D consistency. Existing approaches are highly complex, with many separately trained stages and components. We propose a simple alternative: an image-to-image GAN that maps directly from reprojections of incomplete point clouds to full high-resolution RGB-D images. On the Matterport3D and RealEstate10K datasets, our approach significantly outperforms prior work when evaluated by humans, as well as on FID scores. Further, we show that our model is useful for generative data augmentation. A vision-and-language navigation (VLN) agent trained with trajectories spatially-perturbed by our model improves success rate by up to 1.5% over a state of the art baseline on the R2R benchmark. Our code will be made available to facilitate generative data augmentation and applications to downstream robotics and embodied AI tasks.

生成模型已成为许多图像合成和编辑任务的基本构件。该领域的最新进展还使得能够生成具有多视图或时间一致性的高质量3D或视频内容。在我们的工作中，我们探索了学习无条件生成3D感知视频的4D生成对抗网络（GAN）。通过将神经隐式表示与时间感知歧视器相结合，我们开发了一个GAN框架，该框架仅通过单眼视频进行监督的3D视频。我们表明，我们的方法学习了可分解的3D结构和动作的丰富嵌入，这些结构和动作可以使时空渲染的新视觉效果，同时以与现有3D或视频gan相当的质量产生图像。

We address the problem of synthesizing novel views from a monocular video depicting a complex dynamic scene. State-of-the-art methods based on temporally varying Neural Radiance Fields (aka dynamic NeRFs) have shown impressive results on this task. However, for long videos with complex object motions and uncontrolled camera trajectories, these methods can produce blurry or inaccurate renderings, hampering their use in real-world applications. Instead of encoding the entire dynamic scene within the weights of an MLP, we present a new approach that addresses these limitations by adopting a volumetric image-based rendering framework that synthesizes new viewpoints by aggregating features from nearby views in a scene-motion-aware manner. Our system retains the advantages of prior methods in its ability to model complex scenes and view-dependent effects, but also enables synthesizing photo-realistic novel views from long videos featuring complex scene dynamics with unconstrained camera trajectories. We demonstrate significant improvements over state-of-the-art methods on dynamic scene datasets, and also apply our approach to in-the-wild videos with challenging camera and object motion, where prior methods fail to produce high-quality renderings. Our project webpage is at dynibar.github.io.

我们介绍了Fadiv-Syn，一种快速深入的新型观点合成方法。相关方法通常受到它们的深度估计阶段的限制，其中不正确的深度预测可能导致大的投影误差。为避免此问题，我们将输入图像有效地将输入图像呈现为目标帧，以为一系列假定的深度平面。得到的平面扫描量（PSV）直接进入我们的网络，首先以自我监督的方式估计软PSV掩模，然后直接产生新颖的输出视图。因此，我们侧行显式深度估计。这提高了透明，反光，薄，特色场景部件上的效率和性能。 Fadiv-syn可以在大规模Realestate10K数据集上执行插值和外推任务，优于最先进的外推方法。与可比方法相比，它由于其轻量级架构而实现了实时性能。我们彻底评估消融，例如去除软掩蔽网络，从更少的示例中培训以及更高的分辨率和更强深度离散化的概括。

Existing neural rendering methods for creating human avatars typically either require dense input signals such as video or multi-view images, or leverage a learned prior from large-scale specific 3D human datasets such that reconstruction can be performed with sparse-view inputs. Most of these methods fail to achieve realistic reconstruction when only a single image is available. To enable the data-efficient creation of realistic animatable 3D humans, we propose ELICIT, a novel method for learning human-specific neural radiance fields from a single image. Inspired by the fact that humans can easily reconstruct the body geometry and infer the full-body clothing from a single image, we leverage two priors in ELICIT: 3D geometry prior and visual semantic prior. Specifically, ELICIT introduces the 3D body shape geometry prior from a skinned vertex-based template model (i.e., SMPL) and implements the visual clothing semantic prior with the CLIP-based pre-trained models. Both priors are used to jointly guide the optimization for creating plausible content in the invisible areas. In order to further improve visual details, we propose a segmentation-based sampling strategy that locally refines different parts of the avatar. Comprehensive evaluations on multiple popular benchmarks, including ZJU-MoCAP, Human3.6M, and DeepFashion, show that ELICIT has outperformed current state-of-the-art avatar creation methods when only a single image is available. Code will be public for reseach purpose at https://elicit3d.github.io .

StyleGAN has achieved great progress in 2D face reconstruction and semantic editing via image inversion and latent editing. While studies over extending 2D StyleGAN to 3D faces have emerged, a corresponding generic 3D GAN inversion framework is still missing, limiting the applications of 3D face reconstruction and semantic editing. In this paper, we study the challenging problem of 3D GAN inversion where a latent code is predicted given a single face image to faithfully recover its 3D shapes and detailed textures. The problem is ill-posed: innumerable compositions of shape and texture could be rendered to the current image. Furthermore, with the limited capacity of a global latent code, 2D inversion methods cannot preserve faithful shape and texture at the same time when applied to 3D models. To solve this problem, we devise an effective self-training scheme to constrain the learning of inversion. The learning is done efficiently without any real-world 2D-3D training pairs but proxy samples generated from a 3D GAN. In addition, apart from a global latent code that captures the coarse shape and texture information, we augment the generation network with a local branch, where pixel-aligned features are added to faithfully reconstruct face details. We further consider a new pipeline to perform 3D view-consistent editing. Extensive experiments show that our method outperforms state-of-the-art inversion methods in both shape and texture reconstruction quality. Code and data will be released.

我们引入了一个可扩展的框架，用于从RGB-D图像中具有很大不完整的场景覆盖率的新型视图合成。尽管生成的神经方法在2D图像上表现出了惊人的结果，但它们尚未达到相似的影像学结果，并结合了场景完成，在这种情况下，空间3D场景的理解是必不可少的。为此，我们提出了一条在基于网格的神经场景表示上执行的生成管道，通过以2.5D-3D-2.5D方式进行场景的分布来完成未观察到的场景部分。我们在3D空间中处理编码的图像特征，并具有几何完整网络和随后的纹理镶嵌网络，以推断缺失区域。最终可以通过与一致性的可区分渲染获得感性图像序列。全面的实验表明，我们方法的图形输出优于最新技术，尤其是在未观察到的场景部分中。

Image view synthesis has seen great success in reconstructing photorealistic visuals, thanks to deep learning and various novel representations. The next key step in immersive virtual experiences is view synthesis of dynamic scenes. However, several challenges exist due to the lack of high-quality training datasets, and the additional time dimension for videos of dynamic scenes. To address this issue, we introduce a multi-view video dataset, captured with a custom 10-camera rig in 120FPS. The dataset contains 96 high-quality scenes showing various visual effects and human interactions in outdoor scenes. We develop a new algorithm, Deep 3D Mask Volume, which enables temporally-stable view extrapolation from binocular videos of dynamic scenes, captured by static cameras. Our algorithm addresses the temporal inconsistency of disocclusions by identifying the error-prone areas with a 3D mask volume, and replaces them with static background observed throughout the video. Our method enables manipulation in 3D space as opposed to simple 2D masks, We demonstrate better temporal stability than frame-by-frame static view synthesis methods, or those that use 2D masks. The resulting view synthesis videos show minimal flickering artifacts and allow for larger translational movements.

https://video-nerf.github.io Figure 1. Our method takes a single casually captured video as input and learns a space-time neural irradiance field. (Top) Sample frames from the input video. (Middle) Novel view images rendered from textured meshes constructed from depth maps. (Bottom) Our results rendered from the proposed space-time neural irradiance field.

What is a rose, visually? A rose comprises its intrinsics, including the distribution of geometry, texture, and material specific to its object category. With knowledge of these intrinsic properties, we may render roses of different sizes and shapes, in different poses, and under different lighting conditions. In this work, we build a generative model that learns to capture such object intrinsics from a single image, such as a photo of a bouquet. Such an image includes multiple instances of an object type. These instances all share the same intrinsics, but appear different due to a combination of variance within these intrinsics and differences in extrinsic factors, such as pose and illumination. Experiments show that our model successfully learns object intrinsics (distribution of geometry, texture, and material) for a wide range of objects, each from a single Internet image. Our method achieves superior results on multiple downstream tasks, including intrinsic image decomposition, shape and image generation, view synthesis, and relighting.

新颖的视图合成（NVS）和视频预测（VP）通常被视为计算机视觉中的不相交任务。但是，它们都可以看作是观察空间时代世界的方法：NVS的目的是从新的角度综合一个场景，而副总裁则旨在从新的时间点观看场景。这两个任务提供了互补的信号以获得场景表示形式，因为观点从空间观察中变化为深度的变化，并且时间观察为相机和单个对象的运动提供了信息。受这些观察的启发，我们建议研究时空（背心）中视频外推的问题。我们提出了一个模型，该模型利用了两项任务的自学和互补线索，而现有方法只能解决其中之一。实验表明，我们的方法比室内和室外现实世界数据集上的几种最先进的NVS和VP方法更好地实现了性能。

Recent advances in generative adversarial networks (GANs) have demonstrated the capabilities of generating stunning photo-realistic portrait images. While some prior works have applied such image GANs to unconditional 2D portrait video generation and static 3D portrait synthesis, there are few works successfully extending GANs for generating 3D-aware portrait videos. In this work, we propose PV3D, the first generative framework that can synthesize multi-view consistent portrait videos. Specifically, our method extends the recent static 3D-aware image GAN to the video domain by generalizing the 3D implicit neural representation to model the spatio-temporal space. To introduce motion dynamics to the generation process, we develop a motion generator by stacking multiple motion layers to generate motion features via modulated convolution. To alleviate motion ambiguities caused by camera/human motions, we propose a simple yet effective camera condition strategy for PV3D, enabling both temporal and multi-view consistent video generation. Moreover, PV3D introduces two discriminators for regularizing the spatial and temporal domains to ensure the plausibility of the generated portrait videos. These elaborated designs enable PV3D to generate 3D-aware motion-plausible portrait videos with high-quality appearance and geometry, significantly outperforming prior works. As a result, PV3D is able to support many downstream applications such as animating static portraits and view-consistent video motion editing. Code and models will be released at https://showlab.github.io/pv3d.

使用单视图2D照片仅集合，无监督的高质量多视图 - 一致的图像和3D形状一直是一个长期存在的挑战。现有的3D GAN是计算密集型的，也是没有3D-一致的近似;前者限制了所生成的图像的质量和分辨率，并且后者对多视图一致性和形状质量产生不利影响。在这项工作中，我们提高了3D GAN的计算效率和图像质量，而无需依赖这些近似。为此目的，我们介绍了一种表现力的混合明确隐式网络架构，与其他设计选择一起，不仅可以实时合成高分辨率多视图一致图像，而且还产生高质量的3D几何形状。通过解耦特征生成和神经渲染，我们的框架能够利用最先进的2D CNN生成器，例如Stylega2，并继承它们的效率和表现力。在其他实验中，我们展示了与FFHQ和AFHQ猫的最先进的3D感知合成。

我们提出了HRF-NET，这是一种基于整体辐射场的新型视图合成方法，该方法使用一组稀疏输入来呈现新视图。最近的概括视图合成方法还利用了光辉场，但渲染速度不是实时的。现有的方法可以有效地训练和呈现新颖的观点，但它们无法概括地看不到场景。我们的方法解决了用于概括视图合成的实时渲染问题，并由两个主要阶段组成：整体辐射场预测指标和基于卷积的神经渲染器。该架构不仅基于隐式神经场的一致场景几何形状，而且还可以使用单个GPU有效地呈现新视图。我们首先在DTU数据集的多个3D场景上训练HRF-NET，并且网络只能仅使用光度损耗就看不见的真实和合成数据产生合理的新视图。此外，我们的方法可以利用单个场景的密集参考图像集来产生准确的新颖视图，而无需依赖其他明确表示，并且仍然保持了预训练模型的高速渲染。实验结果表明，HRF-NET优于各种合成和真实数据集的最先进的神经渲染方法。