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.

深度学习识别的进步导致使用2D图像准确的对象检测。然而，这些2D感知方法对于完整的3D世界信息不足。同时，高级3D形状估计接近形状本身的焦点，而不考虑公制量表。这些方法无法确定对象的准确位置和方向。为了解决这个问题，我们提出了一个框架，该框架共同估计了从单个RGB图像的度量标度形状和姿势。我们的框架有两个分支：公制刻度对象形状分支（MSO）和归一化对象坐标空间分支（NOC）。 MSOS分支估计在相机坐标中观察到的度量标准形状。 NOCS分支预测归一化对象坐标空间（NOCS）映射，并从预测的度量刻度网格与渲染的深度图执行相似性转换，以获得6D姿势和大小。此外，我们介绍了归一化对象中心估计（NOCE），以估计从相机到物体中心的几何对齐距离。我们在合成和实际数据集中验证了我们的方法，以评估类别级对象姿势和形状。

我们提出了一种称为DPODV2（密集姿势对象检测器）的三个阶段6 DOF对象检测方法，该方法依赖于致密的对应关系。我们将2D对象检测器与密集的对应关系网络和多视图姿势细化方法相结合，以估计完整的6 DOF姿势。与通常仅限于单眼RGB图像的其他深度学习方法不同，我们提出了一个统一的深度学习网络，允许使用不同的成像方式（RGB或DEPTH）。此外，我们提出了一种基于可区分渲染的新型姿势改进方法。主要概念是在多个视图中比较预测并渲染对应关系，以获得与所有视图中预测的对应关系一致的姿势。我们提出的方法对受控设置中的不同数据方式和培训数据类型进行了严格的评估。主要结论是，RGB在对应性估计中表现出色，而如果有良好的3D-3D对应关系，则深度有助于姿势精度。自然，他们的组合可以实现总体最佳性能。我们进行广泛的评估和消融研究，以分析和验证几个具有挑战性的数据集的结果。 DPODV2在所有这些方面都取得了出色的成果，同时仍然保持快速和可扩展性，独立于使用的数据模式和培训数据的类型

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.

Estimating 6D poses of objects from images is an important problem in various applications such as robot manipulation and virtual reality. While direct regression of images to object poses has limited accuracy, matching rendered images of an object against the input image can produce accurate results. In this work, we propose a novel deep neural network for 6D pose matching named DeepIM. Given an initial pose estimation, our network is able to iteratively refine the pose by matching the rendered image against the observed image. The network is trained to predict a relative pose transformation using a disentangled representation of 3D location and 3D orientation and an iterative training process. Experiments on two commonly used benchmarks for 6D pose estimation demonstrate that DeepIM achieves large improvements over stateof-the-art methods. We furthermore show that DeepIM is able to match previously unseen objects.

6D对象姿势估计是计算机视觉和机器人研究中的基本问题之一。尽管最近在同一类别内将姿势估计概括为新的对象实例（即类别级别的6D姿势估计）方面已做出了许多努力，但考虑到有限的带注释数据，它仍然在受限的环境中受到限制。在本文中，我们收集了Wild6D，这是一种具有不同实例和背景的新的未标记的RGBD对象视频数据集。我们利用这些数据在野外概括了类别级别的6D对象姿势效果，并通过半监督学习。我们提出了一个新模型，称为呈现姿势估计网络reponet，该模型使用带有合成数据的自由地面真实性共同训练，以及在现实世界数据上具有轮廓匹配的目标函数。在不使用实际数据上的任何3D注释的情况下，我们的方法优于先前数据集上的最先进方法，而我们的WILD6D测试集（带有手动注释进行评估）则优于较大的边距。带有WILD6D数据的项目页面：https：//oasisyang.github.io/semi-pose。

RGB图像的刚性对象的可伸缩6D构成估计旨在处理多个对象并推广到新物体。我们建立在一个著名的自动编码框架的基础上，以应对对象对称性和缺乏标记的训练数据，我们通过将自动编码器的潜在表示形状分解为形状并构成子空间来实现可伸缩性。潜在形状空间通过对比度度量学习模型不同对象的相似性，并将潜在姿势代码与旋转检索的规范旋转进行比较。由于不同的对象对称会诱导不一致的潜在姿势空间，因此我们用规范旋转重新输入形状表示，以生成形状依赖的姿势代码簿以进行旋转检索。我们在两个基准上显示了最新的性能，其中包含无类别和每日对象的无纹理CAD对象，并通过扩展到跨类别的每日对象的更具挑战性的设置，进一步证明了可扩展性。

In this paper, we propose a novel 3D graph convolution based pipeline for category-level 6D pose and size estimation from monocular RGB-D images. The proposed method leverages an efficient 3D data augmentation and a novel vector-based decoupled rotation representation. Specifically, we first design an orientation-aware autoencoder with 3D graph convolution for latent feature learning. The learned latent feature is insensitive to point shift and size thanks to the shift and scale-invariance properties of the 3D graph convolution. Then, to efficiently decode the rotation information from the latent feature, we design a novel flexible vector-based decomposable rotation representation that employs two decoders to complementarily access the rotation information. The proposed rotation representation has two major advantages: 1) decoupled characteristic that makes the rotation estimation easier; 2) flexible length and rotated angle of the vectors allow us to find a more suitable vector representation for specific pose estimation task. Finally, we propose a 3D deformation mechanism to increase the generalization ability of the pipeline. Extensive experiments show that the proposed pipeline achieves state-of-the-art performance on category-level tasks. Further, the experiments demonstrate that the proposed rotation representation is more suitable for the pose estimation tasks than other rotation representations.

本文提出了一种类别级别的6D对象姿势和形状估计方法IDAPS，其允许在类别中跟踪6D姿势并估计其3D形状。我们使用深度图像作为输入开发类别级别自动编码器网络，其中来自自动编码器编码的特征嵌入在类别中对象的姿势。自动编码器可用于粒子过滤器框架，以估计和跟踪类别中的对象的姿势。通过利用基于符号距离函数的隐式形状表示，我们构建延迟网络以估计给定对象的估计姿势的3D形状的潜在表示。然后，估计的姿势和形状可用于以迭代方式互相更新。我们的类别级别6D对象姿势和形状估计流水线仅需要2D检测和分段进行初始化。我们在公开的数据集中评估我们的方法，并展示其有效性。特别是，我们的方法在形状估计上实现了相对高的准确性。

In this work, we study 3D object detection from RGB-D data in both indoor and outdoor scenes. While previous methods focus on images or 3D voxels, often obscuring natural 3D patterns and invariances of 3D data, we directly operate on raw point clouds by popping up RGB-D scans. However, a key challenge of this approach is how to efficiently localize objects in point clouds of large-scale scenes (region proposal). Instead of solely relying on 3D proposals, our method leverages both mature 2D object detectors and advanced 3D deep learning for object localization, achieving efficiency as well as high recall for even small objects. Benefited from learning directly in raw point clouds, our method is also able to precisely estimate 3D bounding boxes even under strong occlusion or with very sparse points. Evaluated on KITTI and SUN RGB-D 3D detection benchmarks, our method outperforms the state of the art by remarkable margins while having real-time capability. * Majority of the work done as an intern at Nuro, Inc. depth to point cloud 2D region (from CNN) to 3D frustum 3D box (from PointNet)

我们呈现ROCA，一种新的端到端方法，可以从形状数据库到单个输入图像中检索并对齐3D CAD模型。这使得从2D RGB观察开始观察到的场景的3D感知，其特征在于轻质，紧凑，清洁的CAD表示。我们的方法的核心是我们基于密集的2D-3D对象对应关系和促使对齐的可差的对准优化。因此，罗卡可以提供强大的CAD对准，同时通过利用2D-3D对应关系来学习几何上类似CAD模型来同时通知CAD检索。SCANNET的真实世界图像实验表明，Roca显着提高了现有技术，从检索感知CAD准确度为9.5％至17.6％。

We introduce MegaPose, a method to estimate the 6D pose of novel objects, that is, objects unseen during training. At inference time, the method only assumes knowledge of (i) a region of interest displaying the object in the image and (ii) a CAD model of the observed object. The contributions of this work are threefold. First, we present a 6D pose refiner based on a render&compare strategy which can be applied to novel objects. The shape and coordinate system of the novel object are provided as inputs to the network by rendering multiple synthetic views of the object's CAD model. Second, we introduce a novel approach for coarse pose estimation which leverages a network trained to classify whether the pose error between a synthetic rendering and an observed image of the same object can be corrected by the refiner. Third, we introduce a large-scale synthetic dataset of photorealistic images of thousands of objects with diverse visual and shape properties and show that this diversity is crucial to obtain good generalization performance on novel objects. We train our approach on this large synthetic dataset and apply it without retraining to hundreds of novel objects in real images from several pose estimation benchmarks. Our approach achieves state-of-the-art performance on the ModelNet and YCB-Video datasets. An extensive evaluation on the 7 core datasets of the BOP challenge demonstrates that our approach achieves performance competitive with existing approaches that require access to the target objects during training. Code, dataset and trained models are available on the project page: https://megapose6d.github.io/.

我们提出了一种对类别级别的6D对象姿势和大小估计的新方法。为了解决类内的形状变化，我们学习规范形状空间（CASS），统一表示，用于某个对象类别的各种情况。特别地，CASS被建模为具有标准化姿势的规范3D形状深度生成模型的潜在空间。我们训练变形式自动编码器（VAE），用于从RGBD图像中的规范空间中生成3D点云。 VAE培训以跨类方式培训，利用公开的大型3D形状存储库。由于3D点云在归一化姿势（具有实际尺寸）中生成，因此VAE的编码器学习视图分解RGBD嵌入。它将RGBD图像映射到任意视图中以独立于姿势的3D形状表示。然后通过将对象姿势与用单独的深神经网络提取的输入RGBD的姿势相关的特征进行对比姿势估计。我们将CASS和姿势和大小估计的学习集成到最终的培训网络中，实现了最先进的性能。

We propose a single-shot approach for simultaneously detecting an object in an RGB image and predicting its 6D pose without requiring multiple stages or having to examine multiple hypotheses. Unlike a recently proposed single-shot technique for this task [11] that only predicts an approximate 6D pose that must then be refined, ours is accurate enough not to require additional post-processing. As a result, it is much faster -50 fps on a Titan X (Pascal) GPU -and more suitable for real-time processing. The key component of our method is a new CNN architecture inspired by [28,29] that directly predicts the 2D image locations of the projected vertices of the object's 3D bounding box. The object's 6D pose is then estimated using a PnP algorithm.For single object and multiple object pose estimation on the LINEMOD and OCCLUSION datasets, our approach substantially outperforms other recent 26] when they are all used without postprocessing. During post-processing, a pose refinement step can be used to boost the accuracy of these two methods, but at 10 fps or less, they are much slower than our method.

Estimating the 6D pose of known objects is important for robots to interact with the real world. The problem is challenging due to the variety of objects as well as the complexity of a scene caused by clutter and occlusions between objects. In this work, we introduce PoseCNN, a new Convolutional Neural Network for 6D object pose estimation. PoseCNN estimates the 3D translation of an object by localizing its center in the image and predicting its distance from the camera. The 3D rotation of the object is estimated by regressing to a quaternion representation. We also introduce a novel loss function that enables PoseCNN to handle symmetric objects. In addition, we contribute a large scale video dataset for 6D object pose estimation named the YCB-Video dataset. Our dataset provides accurate 6D poses of 21 objects from the YCB dataset observed in 92 videos with 133,827 frames. We conduct extensive experiments on our YCB-Video dataset and the OccludedLINEMOD dataset to show that PoseCNN is highly robust to occlusions, can handle symmetric objects, and provide accurate pose estimation using only color images as input. When using depth data to further refine the poses, our approach achieves state-of-the-art results on the challenging OccludedLINEMOD dataset. Our code and dataset are available at https://rse-lab.cs.washington.edu/projects/posecnn/.

We present ObjectMatch, a semantic and object-centric camera pose estimation for RGB-D SLAM pipelines. Modern camera pose estimators rely on direct correspondences of overlapping regions between frames; however, they cannot align camera frames with little or no overlap. In this work, we propose to leverage indirect correspondences obtained via semantic object identification. For instance, when an object is seen from the front in one frame and from the back in another frame, we can provide additional pose constraints through canonical object correspondences. We first propose a neural network to predict such correspondences on a per-pixel level, which we then combine in our energy formulation with state-of-the-art keypoint matching solved with a joint Gauss-Newton optimization. In a pairwise setting, our method improves registration recall of state-of-the-art feature matching from 77% to 87% overall and from 21% to 52% in pairs with 10% or less inter-frame overlap. In registering RGB-D sequences, our method outperforms cutting-edge SLAM baselines in challenging, low frame-rate scenarios, achieving more than 35% reduction in trajectory error in multiple scenes.

We introduce a novel method for 3D object detection and pose estimation from color images only. We first use segmentation to detect the objects of interest in 2D even in presence of partial occlusions and cluttered background. By contrast with recent patch-based methods, we rely on a "holistic" approach: We apply to the detected objects a Convolutional Neural Network (CNN) trained to predict their 3D poses in the form of 2D projections of the corners of their 3D bounding boxes. This, however, is not sufficient for handling objects from the recent T-LESS dataset: These objects exhibit an axis of rotational symmetry, and the similarity of two images of such an object under two different poses makes training the CNN challenging. We solve this problem by restricting the range of poses used for training, and by introducing a classifier to identify the range of a pose at run-time before estimating it. We also use an optional additional step that refines the predicted poses. We improve the state-of-the-art on the LINEMOD dataset from 73.7% [2] to 89.3% of correctly registered RGB frames. We are also the first to report results on the Occlusion dataset [1] using color images only. We obtain 54% of frames passing the Pose 6D criterion on average on several sequences of the T-LESS dataset, compared to the 67% of the state-of-the-art [10] on the same sequences which uses both color and depth. The full approach is also scalable, as a single network can be trained for multiple objects simultaneously.

类别级别的姿势估计是由于类内形状变化而导致的一个具有挑战性的问题。最近的方法变形了预计的形状先验，将观察到的点云映射到归一化对象坐标空间中，然后通过后处理（即Umeyama的算法）检索姿势。这种两阶段策略的缺点在于两个方面：1）中间结果的替代监督无法直接指导姿势的学习，从而导致后期处理后造成了较大的姿势错误。 2）推理速度受后处理步骤的限制。在本文中，为了处理这些缺点，我们为类别级别的姿势估计提出了一个可端到端的可训练网络SSP置换，该网络将Shape Priors整合到直接的姿势回归网络中。 SSP置位堆栈在共享特征提取器上的四个单独分支，其中两个分支旨在变形和匹配先前的模型与观察到的实例，并应用了其他两个分支，以直接回归完全9度的自由度姿势和分别执行对称性重建和点对上的掩码预测。然后，自然利用一致性损失项，以对齐不同分支的产出并促进性能。在推断期间，仅需要直接姿势回归分支。通过这种方式，SSP置态不仅学习类别级别的姿势敏感特征以提高性能，而且还可以保持实时推理速度。此外，我们利用每个类别的对称信息来指导形状事先变形，并提出一种新颖的对称性损失来减轻匹配的歧义。公共数据集的广泛实验表明，与竞争对手相比，SSP置孔在约25Hz的实时推理速度中产生了出色的性能。

虽然最近出现了类别级的9DOF对象姿势估计，但由于较大的对象形状和颜色等类别内差异，因此，先前基于对应的或直接回归方法的准确性均受到限制。 - 级别的物体姿势和尺寸炼油机Catre，能够迭代地增强点云的姿势估计以产生准确的结果。鉴于初始姿势估计，Catre通过对齐部分观察到的点云和先验的抽象形状来预测初始姿势和地面真理之间的相对转换。具体而言，我们提出了一种新颖的分离体系结构，以了解旋转与翻译/大小估计之间的固有区别。广泛的实验表明，我们的方法在REAL275，Camera25和LM基准测试中的最先进方法高达〜85.32Hz，并在类别级别跟踪上取得了竞争成果。我们进一步证明，Catre可以对看不见的类别进行姿势改进。可以使用代码和训练有素的型号。

最近，基于RGBD的类别级别6D对象姿势估计已实现了有希望的性能提高，但是，深度信息的要求禁止更广泛的应用。为了缓解这个问题，本文提出了一种新的方法，名为“对象级别深度重建网络”（旧网）仅将RGB图像作为类别级别6D对象姿势估计的输入。我们建议通过将类别级别的形状在对象级深度和规范的NOC表示中直接从单眼RGB图像中直接预测对象级的深度。引入了两个名为归一化的全局位置提示（NGPH）和形状吸引的脱钩深度重建（SDDR）模块的模块，以学习高保真对象级的深度和精致的形状表示。最后，通过将预测的规范表示与背面预测的对象级深度对齐来解决6D对象姿势。在具有挑战性的Camera25和Real275数据集上进行了广泛的实验，表明我们的模型虽然很简单，但可以实现最先进的性能。