This paper focuses on semantic scene completion, a task for producing a complete 3D voxel representation of volumetric occupancy and semantic labels for a scene from a single-view depth map observation. Previous work has considered scene completion and semantic labeling of depth maps separately. However, we observe that these two problems are tightly intertwined. To leverage the coupled nature of these two tasks, we introduce the semantic scene completion network (SSCNet), an end-to-end 3D convolutional network that takes a single depth image as input and simultaneously outputs occupancy and semantic labels for all voxels in the camera view frustum. Our network uses a dilation-based 3D context module to efficiently expand the receptive field and enable 3D context learning. To train our network, we construct SUNCG -a manually created largescale dataset of synthetic 3D scenes with dense volumetric annotations. Our experiments demonstrate that the joint model outperforms methods addressing each task in isolation and outperforms alternative approaches on the semantic scene completion task. The dataset, code and pretrained model will be available online upon acceptance.

We focus on the task of amodal 3D object detection in RGB-D images, which aims to produce a 3D bounding box of an object in metric form at its full extent. We introduce Deep Sliding Shapes, a 3D ConvNet formulation that takes a 3D volumetric scene from a RGB-D image as input and outputs 3D object bounding boxes. In our approach, we propose the first 3D Region Proposal Network (RPN) to learn objectness from geometric shapes and the first joint Object Recognition Network (ORN) to extract geometric features in 3D and color features in 2D. In particular, we handle objects of various sizes by training an amodal RPN at two different scales and an ORN to regress 3D bounding boxes. Experiments show that our algorithm outperforms the state-of-the-art by 13.8 in mAP and is 200× faster than the original Sliding Shapes. Source code and pre-trained models are available.

3D shape is a crucial but heavily underutilized cue in today's computer vision systems, mostly due to the lack of a good generic shape representation. With the recent availability of inexpensive 2.5D depth sensors (e.g. Microsoft Kinect), it is becoming increasingly important to have a powerful 3D shape representation in the loop. Apart from category recognition, recovering full 3D shapes from viewbased 2.5D depth maps is also a critical part of visual understanding. To this end, we propose to represent a geometric 3D shape as a probability distribution of binary variables on a 3D voxel grid, using a Convolutional Deep Belief Network. Our model, 3D ShapeNets, learns the distribution of complex 3D shapes across different object categories and arbitrary poses from raw CAD data, and discovers hierarchical compositional part representations automatically. It naturally supports joint object recognition and shape completion from 2.5D depth maps, and it enables active object recognition through view planning. To train our 3D deep learning model, we construct ModelNet -a large-scale 3D CAD model dataset. Extensive experiments show that our 3D deep representation enables significant performance improvement over the-state-of-the-arts in a variety of tasks.

A key requirement for leveraging supervised deep learning methods is the availability of large, labeled datasets. Unfortunately, in the context of RGB-D scene understanding, very little data is available -current datasets cover a small range of scene views and have limited semantic annotations. To address this issue, we introduce ScanNet, an RGB-D video dataset containing 2.5M views in 1513 scenes annotated with 3D camera poses, surface reconstructions, and semantic segmentations. To collect this data, we designed an easy-to-use and scalable RGB-D capture system that includes automated surface reconstruction and crowdsourced semantic annotation. We show that using this data helps achieve state-of-the-art performance on several 3D scene understanding tasks, including 3D object classification, semantic voxel labeling, and CAD model retrieval.

Our method completes a partial 3D scan using a 3D Encoder-Predictor network that leverages semantic features from a 3D classification network. The predictions are correlated with a shape database, which we use in a multi-resolution 3D shape synthesis step. We obtain completed high-resolution meshes that are inferred from partial, low-resolution input scans.

了解单个图像的3D场景是各种任务的基础，例如用于机器人，运动规划或增强现实。来自单个RGB图像的3D感知的现有工作倾向于专注于几何重建，或用语义分割或实例分割的几何重建。受到2D Panoptic分割的启发，我们建议统一几何重建，3D语义分割和3D实例分段的任务，进入Panoptic 3D场景重建的任务 - 从单个RGB图像预测相机中场景的完整几何重建图像的截图，以及语义和实例分割。因此，我们为从单个RGB图像提出了一种全新3D场景的新方法，该方法学习从输入图像到达3D容量场景表示来升力和传播2D特征。我们证明，这种联合场景重建，语义和实例分割的整体视图是有益的，独立地处理任务，从而优于替代方法。

Access to large, diverse RGB-D datasets is critical for training RGB-D scene understanding algorithms. However, existing datasets still cover only a limited number of views or a restricted scale of spaces. In this paper, we introduce Matterport3D, a large-scale RGB-D dataset containing 10,800 panoramic views from 194,400 RGB-D images of 90 building-scale scenes. Annotations are provided with surface reconstructions, camera poses, and 2D and 3D semantic segmentations. The precise global alignment and comprehensive, diverse panoramic set of views over entire buildings enable a variety of supervised and self-supervised computer vision tasks, including keypoint matching, view overlap prediction, normal prediction from color, semantic segmentation, and region classification.

最近的体积三维重建方法可以产生非常精确的结果，即使对于未观察的表面，也可以具有合理的几何形状。然而，当涉及多视图融合时，它们面临着不希望的权衡。它们可以通过全局平均来熔断所有可用视图信息，从而丢失精细的细节，或者他们可以启发式群集对本地融合的群集视图，从而限制他们共同考虑所有视图的能力。我们的关键洞察力是通过在摄像机姿势和图像内容上学习视图融合功能，可以在不限制视图多样性的情况下保留更详细的详细信息。我们建议使用变压器学习此多视图融合。为此，我们使用变压器介绍Vortx，一个端到端的体积3D重建网络，用于宽基线，多视图功能融合。我们的模型是遮挡感知的，利用变压器架构来预测初始投影场景几何估计。该估计用于避免将反射图像特征通过曲面到遮挡区域。我们在Scannet上培训我们的模型，并显示它比最先进的方法产生更好的重建。我们还展示了概括，没有任何微调，优于两个其他数据集，Tum-RGBD和ICL-Nuim的相同最先进的方法。

我们在本文中重新审视语义场景（SSC），是预测3D场景的语义和占用表示的有用任务。此任务的许多方法始终基于用于保存本地场景结构的体蛋白化场景表示。然而，由于存在可见空体素，当网络更深时，这些方法总是遭受重型计算冗余，从而限制完成质量。为了解决这种困境，我们提出了我们为此任务的新型点体素聚集网络。首先，我们通过去除这些可见的空体素来将Voxized场景传输到点云，并采用深点流，以有效地从场景中捕获语义信息。同时，仅包含两个3D卷积层的轻重体素流保留了体蛋白化场景的局部结构。此外，我们设计一个各向异性体素聚合运算符，将结构细节从体素流融合到点流中，并通过语义标签来增强点流中的上采样过程的语义感知传播模块。我们展示了我们的模型在两个基准上超越了最先进的余量，只有深度图像作为输入。

语义场景完成（SSC）是一个具有挑战性的计算机视觉任务，具有许多实际应用，从机器人到辅助计算。其目标是在场景的视野中推断3D几何图形和体素的语义标记，包括遮挡区域。在这项工作中，我们呈现出来，一种新型轻质多模式3D深CNN，其与来自BiMoDal 2D分段网络的语义前沿的RGB-D图像的深度分量无缝地熔化结构数据。这一领域的一个至关重要的困难是缺乏完全标记的现实世界3D数据集，足以训练当前的数据饥饿的深3d CNN。在2D计算机愿景任务中，已提出许多数据增强策略来改善CNN的泛化能力。但是，这些方法不能直接应用于RGB-D输入和SSC解决方案的输出量。在本文中，我们介绍了可以应用于多模式SSC网络的3D数据增强策略的使用。我们通过全面和可重复的消融研究验证我们的贡献。我们的解决方案始终如一地超越了以前的作品，具有类似的复杂程度。

We present a learnt system for multi-view stereopsis. In contrast to recent learning based methods for 3D reconstruction, we leverage the underlying 3D geometry of the problem through feature projection and unprojection along viewing rays. By formulating these operations in a differentiable manner, we are able to learn the system end-to-end for the task of metric 3D reconstruction. End-to-end learning allows us to jointly reason about shape priors while conforming to geometric constraints, enabling reconstruction from much fewer images (even a single image) than required by classical approaches as well as completion of unseen surfaces. We thoroughly evaluate our approach on the ShapeNet dataset and demonstrate the benefits over classical approaches and recent learning based methods.

6D object pose estimation problem has been extensively studied in the field of Computer Vision and Robotics. It has wide range of applications such as robot manipulation, augmented reality, and 3D scene understanding. With the advent of Deep Learning, many breakthroughs have been made; however, approaches continue to struggle when they encounter unseen instances, new categories, or real-world challenges such as cluttered backgrounds and occlusions. In this study, we will explore the available methods based on input modality, problem formulation, and whether it is a category-level or instance-level approach. As a part of our discussion, we will focus on how 6D object pose estimation can be used for understanding 3D scenes.

3D shape models are becoming widely available and easier to capture, making available 3D information crucial for progress in object classification. Current state-of-theart methods rely on CNNs to address this problem. Recently, we witness two types of CNNs being developed: CNNs based upon volumetric representations versus CNNs based upon multi-view representations. Empirical results from these two types of CNNs exhibit a large gap, indicating that existing volumetric CNN architectures and approaches are unable to fully exploit the power of 3D representations. In this paper, we aim to improve both volumetric CNNs and multi-view CNNs according to extensive analysis of existing approaches. To this end, we introduce two distinct network architectures of volumetric CNNs. In addition, we examine multi-view CNNs, where we introduce multiresolution filtering in 3D. Overall, we are able to outperform current state-of-the-art methods for both volumetric CNNs and multi-view CNNs. We provide extensive experiments designed to evaluate underlying design choices, thus providing a better understanding of the space of methods available for object classification on 3D data.

本文提出了一个实时的在线视觉框架，共同恢复室内场景的3D结构和语义标签。给定嘈杂的深度地图，相机轨迹和火车时间的2D语义标签，所提出的深度神经网络的方法学会融合在场景空间中具有合适的语义标签的框架。我们的方法利用现场特征空间中深度和语义的联合体积表示来解决此任务。对于实时语义标签和几何形状的引人注目的在线融合，我们介绍了一个高效的涡流池块，同时删除了在线深度融合中的路由网络，以保持高频表面细节。我们表明场景的语义提供的上下文信息有助于深度融合网络学习抗噪声功能。不仅如此，它有助于克服当前在线深度融合方法的缺点，在处理薄物体结构，增厚伪像和假表面。 Replica DataSet上的实验评估表明，我们的方法可以在每秒37和10帧中执行深度融合，平均重建F分数分别为88％和91％，具体取决于深度图分辨率。此外，我们的模型在Scannet 3D语义基准排行榜上显示了0.515的平均iou得分。

The goal of this paper is to estimate the 6D pose and dimensions of unseen object instances in an RGB-D image. Contrary to "instance-level" 6D pose estimation tasks, our problem assumes that no exact object CAD models are available during either training or testing time. To handle different and unseen object instances in a given category, we introduce Normalized Object Coordinate Space (NOCS)-a shared canonical representation for all possible object instances within a category. Our region-based neural network is then trained to directly infer the correspondence from observed pixels to this shared object representation (NOCS) along with other object information such as class label and instance mask. These predictions can be combined with the depth map to jointly estimate the metric 6D pose and dimensions of multiple objects in a cluttered scene. To train our network, we present a new contextaware technique to generate large amounts of fully annotated mixed reality data. To further improve our model and evaluate its performance on real data, we also provide a fully annotated real-world dataset with large environment and instance variation. Extensive experiments demonstrate that the proposed method is able to robustly estimate the pose and size of unseen object instances in real environments while also achieving state-of-the-art performance on standard 6D pose estimation benchmarks.

我们介绍了Amazon Berkeley对象（ABO），这是一个新的大型数据集，旨在帮助弥合真实和虚拟3D世界之间的差距。ABO包含产品目录图像，元数据和艺术家创建的3D模型，具有复杂的几何形状和与真实的家用物体相对应的物理基础材料。我们得出了具有挑战性的基准，这些基准利用ABO的独特属性，并测量最先进的对象在三个开放问题上的最新限制，以了解实际3D对象：单视3D 3D重建，材料估计和跨域多视图对象检索。

我们为RGB视频提供了基于变压器的神经网络体系结构，用于多对象3D重建。它依赖于表示知识的两种替代方法：作为特征的全局3D网格和一系列特定的2D网格。我们通过专用双向注意机制在两者之间逐步交换信息。我们利用有关图像形成过程的知识，以显着稀疏注意力重量矩阵，从而使我们的体系结构在记忆和计算方面可行。我们在3D特征网格的顶部附上一个detr风格的头，以检测场景中的对象并预测其3D姿势和3D形状。与以前的方法相比，我们的体系结构是单阶段，端到端可训练，并且可以从整体上考虑来自多个视频帧的场景，而无需脆弱的跟踪步骤。我们在挑战性的SCAN2CAD数据集上评估了我们的方法，在该数据集中，我们的表现要优于RGB视频的3D对象姿势估算的最新最新方法； （2）将多视图立体声与RGB-D CAD对齐结合的强大替代方法。我们计划发布我们的源代码。

现有的计算机视觉系统可以与人类竞争，以理解物体的可见部分，但在描绘部分被遮挡物体的无形部分时，仍然远远远远没有达到人类。图像Amodal的完成旨在使计算机具有类似人类的Amodal完成功能，以了解完整的对象，尽管该对象被部分遮住。这项调查的主要目的是对图像Amodal完成领域的研究热点，关键技术和未来趋势提供直观的理解。首先，我们对这个新兴领域的最新文献进行了全面的评论，探讨了图像Amodal完成中的三个关键任务，包括Amodal形状完成，Amodal外观完成和订单感知。然后，我们检查了与图像Amodal完成有关的流行数据集及其共同的数据收集方法和评估指标。最后，我们讨论了现实世界中的应用程序和未来的研究方向，以实现图像的完成，从而促进了读者对现有技术和即将到来的研究趋势的挑战的理解。

In this work, we present a dense tracking and mapping system named Vox-Fusion, which seamlessly fuses neural implicit representations with traditional volumetric fusion methods. Our approach is inspired by the recently developed implicit mapping and positioning system and further extends the idea so that it can be freely applied to practical scenarios. Specifically, we leverage a voxel-based neural implicit surface representation to encode and optimize the scene inside each voxel. Furthermore, we adopt an octree-based structure to divide the scene and support dynamic expansion, enabling our system to track and map arbitrary scenes without knowing the environment like in previous works. Moreover, we proposed a high-performance multi-process framework to speed up the method, thus supporting some applications that require real-time performance. The evaluation results show that our methods can achieve better accuracy and completeness than previous methods. We also show that our Vox-Fusion can be used in augmented reality and virtual reality applications. Our source code is publicly available at https://github.com/zju3dv/Vox-Fusion.