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.

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.

We propose "factor matting", an alternative formulation of the video matting problem in terms of counterfactual video synthesis that is better suited for re-composition tasks. The goal of factor matting is to separate the contents of video into independent components, each visualizing a counterfactual version of the scene where contents of other components have been removed. We show that factor matting maps well to a more general Bayesian framing of the matting problem that accounts for complex conditional interactions between layers. Based on this observation, we present a method for solving the factor matting problem that produces useful decompositions even for video with complex cross-layer interactions like splashes, shadows, and reflections. Our method is trained per-video and requires neither pre-training on external large datasets, nor knowledge about the 3D structure of the scene. We conduct extensive experiments, and show that our method not only can disentangle scenes with complex interactions, but also outperforms top methods on existing tasks such as classical video matting and background subtraction. In addition, we demonstrate the benefits of our approach on a range of downstream tasks. Please refer to our project webpage for more details: https://factormatte.github.io

我们提出了IM2NERF，这是一个学习框架，该框架可以预测在野生中给出单个输入图像的连续神经对象表示，仅通过现成的识别方法进行分割输出而受到监督。构建神经辐射场的标准方法利用了多视图的一致性，需要对场景的许多校准视图，这一要求在野外学习大规模图像数据时无法满足。我们通过引入一个模型将输入图像编码到包含对象形状的代码，对象外观代码以及捕获对象图像的估计相机姿势的模型来迈出解决此缺点的一步。我们的模型条件在预测的对象表示上nerf，并使用卷渲染来从新视图中生成图像。我们将模型端到端训练大量输入图像。由于该模型仅配有单视图像，因此问题高度不足。因此，除了在合成的输入视图上使用重建损失外，我们还对新颖的视图使用辅助对手损失。此外，我们利用对象对称性和循环摄像头的姿势一致性。我们在Shapenet数据集上进行了广泛的定量和定性实验，并在开放图像数据集上进行了定性实验。我们表明，在所有情况下，IM2NERF都从野外的单视图像中实现了新视图合成的最新性能。

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。

我们提出了一种将任意样式图像的艺术特征转移到3D场景的方法。在点云或网格上执行3D风格的先前方法对复杂的现实世界场景的几何重建错误敏感。取而代之的是，我们建议对更健壮的辐射场字段表示。我们发现，常用的基于克矩阵的损失倾向于在没有忠实笔触的情况下产生模糊的结果，并引入了最近的基于邻居的损失，该损失非常有效地捕获样式的细节，同时保持多视图一致性。我们还提出了一种新颖的递延后传播方法，以使用在全分辨率渲染图像上定义的样式损失来优化记忆密集型辐射场。我们广泛的评估表明，我们的方法通过产生与样式图像更相似的艺术外观来优于基线。请检查我们的项目页面以获取视频结果和开源实现：https：//www.cs.cornell.edu/projects/arf/。

我们介绍从单个视频帧预测的问题，从单个视频帧，包括实际瞬时光流的光流量的低维子空间。我们展示了几种自然场景假设如何通过差异和对象实例的表示，通过一组基流字段来识别适当的流子空间。流量子空间与新颖的丢失函数一起可用于预测单眼深度或预测深度加上对象实例嵌入的任务。这提供了一种新方法，可以使用单眼输入视频以无监督的方式学习这些任务，而无需相机内在或姿势。

We present a method that synthesizes novel views of complex scenes by interpolating a sparse set of nearby views. The core of our method is a network architecture that includes a multilayer perceptron and a ray transformer that estimates radiance and volume density at continuous 5D locations (3D spatial locations and 2D viewing directions), drawing appearance information on the fly from multiple source views. By drawing on source views at render time, our method hearkens back to classic work on image-based rendering (IBR), and allows us to render high-resolution imagery. Unlike neural scene representation work that optimizes per-scene functions for rendering, we learn a generic view interpolation function that generalizes to novel scenes. We render images using classic volume rendering, which is fully differentiable and allows us to train using only multiview posed images as supervision. Experiments show that our method outperforms recent novel view synthesis methods that also seek to generalize to novel scenes. Further, if fine-tuned on each scene, our method is competitive with state-of-the-art single-scene neural rendering methods. 1

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.