对象检测是一项基本的计算机视觉任务，用于在给定图像中loccal和分类对象。大多数最先进的检测方法都利用固定数量的建议作为对象候选物的中间表示，在推理过程中无法适应不同的计算约束。在本文中，我们提出了一种简单而有效的方法，该方法通过生成动态提案以进行对象检测来适应不同的计算资源。我们首先设计一个模块来制作一个基于查询的模型，以便能够使用不同数量的建议进行推断。此外，我们将其扩展到动态模型，以根据输入图像选择建议数量，从而大大降低了计算成本。我们的方法在广泛的检测模型中实现了显着的加速，包括两阶段和基于查询的模型，同时获得相似甚至更好的准确性。

DETR方法中引入的查询机制正在改变对象检测的范例，最近有许多基于查询的方法获得了强对象检测性能。但是，当前基于查询的检测管道遇到了以下两个问题。首先，需要多阶段解码器来优化随机初始化的对象查询，从而产生较大的计算负担。其次，训练后的查询是固定的，导致不满意的概括能力。为了纠正上述问题，我们在较快的R-CNN框架中提出了通过查询生成网络预测的特征对象查询，并开发了一个功能性的查询R-CNN。可可数据集的广泛实验表明，我们的特征查询R-CNN获得了所有R-CNN探测器的最佳速度准确性权衡，包括最近的最新稀疏R-CNN检测器。该代码可在\ url {https://github.com/hustvl/featurized-queryrcnn}中获得。

最近的端到端多对象检测器通过删除手工制作的过程（例如使用非最大最大抑制（NMS））删除手工制作的过程来简化推理管道。但是，在训练中，他们需要两分匹配来计算检测器输出的损失。与端到端学习的核心的方向性相反，双方匹配使端到端探测器复杂，启发式和依赖的培训。在本文中，我们提出了一种训练端到端多对象探测器而无需匹配的方法。为此，我们使用混合模型将端到端多对象检测作为密度估计问题。我们提出的检测器，称为稀疏混合物密度检测器（稀疏MDOD），使用混合模型估算边界盒的分布。稀疏MDOD是通过最大程度地减少负对数似然性和我们提出的正则化项，最大成分最大化（MCM）损失来训练的，从而阻止了重复的预测。在训练过程中，不需要其他过程，例如两分匹配，并且损失是直接从网络输出中计算出来的。此外，我们的稀疏MDOD优于MS-Coco上的现有检测器，MS-Coco是一种著名的多对象检测基准。

两阶段和基于查询的实例分段方法取得了显着的结果。然而，他们的分段面具仍然非常粗糙。在本文中，我们呈现了用于高质量高效的实例分割的掩模转发器。我们的掩模转发器代替常规密集的张量，而不是在常规密集的张量上进行分解，并表示作为Quadtree的图像区域。我们基于变换器的方法仅处理检测到的错误易于树节点，并并行自我纠正其错误。虽然这些稀疏的像素仅构成总数的小比例，但它们对最终掩模质量至关重要。这允许掩模转换器以低计算成本预测高精度的实例掩模。广泛的实验表明，掩模转发器在三个流行的基准上优于当前实例分段方法，显着改善了COCO和BDD100K上的大型+3.0掩模AP的+3.0掩模AP的大余量和CityScapes上的+6.6边界AP。我们的代码和培训的型号将在http://vis.xyz/pub/transfiner提供。

现有的实例分割方法已经达到了令人印象深刻的表现，但仍遭受了共同的困境：一个实例推断出冗余表示（例如，多个框，网格和锚点），这导致了多个重复的预测。因此，主流方法通常依赖于手工设计的非最大抑制（NMS）后处理步骤来选择最佳预测结果，这会阻碍端到端训练。为了解决此问题，我们建议一个称为Uniinst的无盒和无端机实例分割框架，该框架仅对每个实例产生一个唯一的表示。具体而言，我们设计了一种实例意识到的一对一分配方案，即仅产生一个表示（Oyor），该方案根据预测和地面真相之间的匹配质量，动态地为每个实例动态分配一个独特的表示。然后，一种新颖的预测重新排列策略被优雅地集成到框架中，以解决分类评分和掩盖质量之间的错位，从而使学习的表示形式更具歧视性。借助这些技术，我们的Uniinst，第一个基于FCN的盒子和无NMS实例分段框架，实现竞争性能，例如，使用Resnet-50-FPN和40.2 mask AP使用Resnet-101-FPN，使用Resnet-50-FPN和40.2 mask AP，使用Resnet-101-FPN，对抗AP可可测试-DEV的主流方法。此外，提出的实例感知方法对于遮挡场景是可靠的，在重锁定的ochuman基准上，通过杰出的掩码AP优于公共基线。我们的代码将在出版后提供。

虽然用变压器（DETR）的检测越来越受欢迎，但其全球注意力建模需要极其长的培训期，以优化和实现有前途的检测性能。现有研究的替代方案主要开发先进的特征或嵌入设计来解决培训问题，指出，基于地区的兴趣区域（ROI）的检测细化可以很容易地帮助减轻DETR方法培训的难度。基于此，我们在本文中介绍了一种新型的经常性闪闪发光的解码器（Rego）。特别是，REGO采用多级复发处理结构，以帮助更准确地逐渐关注前景物体。在每个处理阶段，从ROI的闪烁特征提取视觉特征，其中来自上阶段的检测结果的放大边界框区域。然后，引入了基于一瞥的解码器，以提供基于前一级的瞥见特征和注意力建模输出的精细检测结果。在实践中，Refo可以很容易地嵌入代表性的DETR变体，同时保持其完全端到端的训练和推理管道。特别地，Refo帮助可变形的DETR在MSCOCO数据集上实现44.8AP，只有36个训练时期，与需要500和50时期的第一DETR和可变形的DETR相比，分别可以分别实现相当的性能。实验还表明，Rego始终如一地提升不同DETR探测器的性能高达7％的相对增益，在相同的50次训练时期。代码可通过https://github.com/zhechen/deformable-detr-rego获得。

Cascade is a classic yet powerful architecture that has boosted performance on various tasks. However, how to introduce cascade to instance segmentation remains an open question. A simple combination of Cascade R-CNN and Mask R-CNN only brings limited gain. In exploring a more effective approach, we find that the key to a successful instance segmentation cascade is to fully leverage the reciprocal relationship between detection and segmentation. In this work, we propose a new framework, Hybrid Task Cascade (HTC), which differs in two important aspects: (1) instead of performing cascaded refinement on these two tasks separately, it interweaves them for a joint multi-stage processing; (2) it adopts a fully convolutional branch to provide spatial context, which can help distinguishing hard foreground from cluttered background. Overall, this framework can learn more discriminative features progressively while integrating complementary features together in each stage. Without bells and whistles, a single HTC obtains 38.4% and 1.5% improvement over a strong Cascade Mask R-CNN baseline on MSCOCO dataset. Moreover, our overall system achieves 48.6 mask AP on the test-challenge split, ranking 1st in the COCO 2018 Challenge Object Detection Task. Code is available at: https://github.com/ open-mmlab/mmdetection.

知识蒸馏在分类中取得了巨大的成功，但是，仍然有挑战性。在用于检测的典型图像中，来自不同位置的表示可能对检测目标具有不同的贡献，使蒸馏难以平衡。在本文中，我们提出了一种有条件的蒸馏框架来蒸馏出所需的知识，即关于每个例子的分类和本地化有益的知识。该框架引入了一种可学习的条件解码模块，其将每个目标实例检索为查询的信息。具体而言，我们将条件信息编码为查询并使用教师的表示作为键。查询和键之间的注意用于测量不同特征的贡献，由本地化识别敏感辅助任务指导。广泛的实验表明了我们的方法的功效：我们在各种环境下观察到令人印象深刻的改进。值得注意的是，在1倍计划下，我们将通过37.4至40.7地图（+3.3）与Reset-50骨架的Restinetet提升。代码已在https://github.com/megvii-research/icd上发布。

检测变压器已在富含样品的可可数据集上实现了竞争性能。但是，我们显示他们中的大多数人在小型数据集（例如CityScapes）上遭受了大量的性能下降。换句话说，检测变压器通常是渴望数据的。为了解决这个问题，我们通过逐步过渡从数据效率的RCNN变体到代表性的DETR，从经验中分析影响数据效率的因素。经验结果表明，来自本地图像区域的稀疏特征采样可容纳关键。基于此观察结果，我们通过简单地简单地交替如何在跨意义层构建键和价值序列，从而减少现有检测变压器的数据问题，并对原始模型进行最小的修改。此外，我们引入了一种简单而有效的标签增强方法，以提供更丰富的监督并提高数据效率。实验表明，我们的方法可以很容易地应用于不同的检测变压器，并在富含样品和样品的数据集上提高其性能。代码将在\ url {https://github.com/encounter1997/de-detrs}上公开提供。

我们为变体视觉任务提供了一个概念上简单，灵活和通用的视觉感知头，例如分类，对象检测，实例分割和姿势估计以及不同的框架，例如单阶段或两个阶段的管道。我们的方法有效地标识了图像中的对象，同时同时生成高质量的边界框或基于轮廓的分割掩码或一组关键点。该方法称为Unihead，将不同的视觉感知任务视为通过变压器编码器体系结构学习的可分配点。给定固定的空间坐标，Unihead将其自适应地分散到了不同的空间点和有关它们的关系的原因。它以多个点的形式直接输出最终预测集，使我们能够在具有相同头部设计的不同框架中执行不同的视觉任务。我们展示了对成像网分类的广泛评估以及可可套件的所有三个曲目，包括对象检测，实例分割和姿势估计。如果没有铃铛和口哨声，Unihead可以通过单个视觉头设计统一这些视觉任务，并与为每个任务开发的专家模型相比，实现可比的性能。我们希望我们的简单和通用的Unihead能够成为可靠的基线，并有助于促进通用的视觉感知研究。代码和型号可在https://github.com/sense-x/unihead上找到。

多年来，使用单点监督的对象检测受到了越来越多的关注。在本文中，我们将如此巨大的性能差距归因于产生高质量的提案袋的失败，这对于多个实例学习至关重要（MIL）。为了解决这个问题，我们引入了现成建议方法（OTSP）方法的轻量级替代方案，从而创建点对点网络（P2BNET），该网络可以通过在中生成建议袋来构建一个互平衡的提案袋一种锚点。通过充分研究准确的位置信息，P2BNET进一步构建了一个实例级袋，避免了多个物体的混合物。最后，以级联方式进行的粗到精细政策用于改善提案和地面真相（GT）之间的IOU。从这些策略中受益，P2BNET能够生产出高质量的实例级袋以进行对象检测。相对于MS可可数据集中的先前最佳PSOD方法，P2BNET将平均平均精度（AP）提高了50％以上。它还证明了弥合监督和边界盒监督检测器之间的性能差距的巨大潜力。该代码将在github.com/ucas-vg/p2bnet上发布。

In this paper we present Mask DINO, a unified object detection and segmentation framework. Mask DINO extends DINO (DETR with Improved Denoising Anchor Boxes) by adding a mask prediction branch which supports all image segmentation tasks (instance, panoptic, and semantic). It makes use of the query embeddings from DINO to dot-product a high-resolution pixel embedding map to predict a set of binary masks. Some key components in DINO are extended for segmentation through a shared architecture and training process. Mask DINO is simple, efficient, and scalable, and it can benefit from joint large-scale detection and segmentation datasets. Our experiments show that Mask DINO significantly outperforms all existing specialized segmentation methods, both on a ResNet-50 backbone and a pre-trained model with SwinL backbone. Notably, Mask DINO establishes the best results to date on instance segmentation (54.5 AP on COCO), panoptic segmentation (59.4 PQ on COCO), and semantic segmentation (60.8 mIoU on ADE20K) among models under one billion parameters. Code is available at \url{https://github.com/IDEACVR/MaskDINO}.

In object detection, the intersection over union (IoU) threshold is frequently used to define positives/negatives. The threshold used to train a detector defines its quality. While the commonly used threshold of 0.5 leads to noisy (low-quality) detections, detection performance frequently degrades for larger thresholds. This paradox of high-quality detection has two causes: 1) overfitting, due to vanishing positive samples for large thresholds, and 2) inference-time quality mismatch between detector and test hypotheses. A multi-stage object detection architecture, the Cascade R-CNN, composed of a sequence of detectors trained with increasing IoU thresholds, is proposed to address these problems. The detectors are trained sequentially, using the output of a detector as training set for the next. This resampling progressively improves hypotheses quality, guaranteeing a positive training set of equivalent size for all detectors and minimizing overfitting. The same cascade is applied at inference, to eliminate quality mismatches between hypotheses and detectors. An implementation of the Cascade R-CNN without bells or whistles achieves state-of-the-art performance on the COCO dataset, and significantly improves high-quality detection on generic and specific object detection datasets, including VOC, KITTI, CityPerson, and WiderFace. Finally, the Cascade R-CNN is generalized to instance segmentation, with nontrivial improvements over the Mask R-CNN. To facilitate future research, two implementations are made available at https://github.com/zhaoweicai/cascade-rcnn (Caffe) and https://github.com/zhaoweicai/Detectron-Cascade-RCNN (Detectron).

We present a conceptually simple, flexible, and general framework for object instance segmentation. Our approach efficiently detects objects in an image while simultaneously generating a high-quality segmentation mask for each instance. The method, called Mask R-CNN, extends Faster R-CNN by adding a branch for predicting an object mask in parallel with the existing branch for bounding box recognition. Mask R-CNN is simple to train and adds only a small overhead to Faster R-CNN, running at 5 fps. Moreover, Mask R-CNN is easy to generalize to other tasks, e.g., allowing us to estimate human poses in the same framework. We show top results in all three tracks of the COCO suite of challenges, including instance segmentation, bounding-box object detection, and person keypoint detection. Without tricks, Mask R-CNN outperforms all existing, single-model entries on every task, including the COCO 2016 challenge winners. We hope our simple and effective approach will serve as a solid baseline and help ease future research in instance-level recognition. Code will be made available.

Feature pyramids are a basic component in recognition systems for detecting objects at different scales. But recent deep learning object detectors have avoided pyramid representations, in part because they are compute and memory intensive. In this paper, we exploit the inherent multi-scale, pyramidal hierarchy of deep convolutional networks to construct feature pyramids with marginal extra cost. A topdown architecture with lateral connections is developed for building high-level semantic feature maps at all scales. This architecture, called a Feature Pyramid Network (FPN), shows significant improvement as a generic feature extractor in several applications. Using FPN in a basic Faster R-CNN system, our method achieves state-of-the-art singlemodel results on the COCO detection benchmark without bells and whistles, surpassing all existing single-model entries including those from the COCO 2016 challenge winners. In addition, our method can run at 6 FPS on a GPU and thus is a practical and accurate solution to multi-scale object detection. Code will be made publicly available.

In object detection, an intersection over union (IoU) threshold is required to define positives and negatives. An object detector, trained with low IoU threshold, e.g. 0.5, usually produces noisy detections. However, detection performance tends to degrade with increasing the IoU thresholds. Two main factors are responsible for this: 1) overfitting during training, due to exponentially vanishing positive samples, and 2) inference-time mismatch between the IoUs for which the detector is optimal and those of the input hypotheses. A multi-stage object detection architecture, the Cascade R-CNN, is proposed to address these problems. It consists of a sequence of detectors trained with increasing IoU thresholds, to be sequentially more selective against close false positives. The detectors are trained stage by stage, leveraging the observation that the output of a detector is a good distribution for training the next higher quality detector. The resampling of progressively improved hypotheses guarantees that all detectors have a positive set of examples of equivalent size, reducing the overfitting problem. The same cascade procedure is applied at inference, enabling a closer match between the hypotheses and the detector quality of each stage. A simple implementation of the Cascade R-CNN is shown to surpass all single-model object detectors on the challenging COCO dataset. Experiments also show that the Cascade R-CNN is widely applicable across detector architectures, achieving consistent gains independently of the baseline detector strength. The code will be made available at https://github.com/zhaoweicai/cascade-rcnn.

In this paper, we introduce an anchor-box free and single shot instance segmentation method, which is conceptually simple, fully convolutional and can be used by easily embedding it into most off-the-shelf detection methods. Our method, termed PolarMask, formulates the instance segmentation problem as predicting contour of instance through instance center classification and dense distance regression in a polar coordinate. Moreover, we propose two effective approaches to deal with sampling high-quality center examples and optimization for dense distance regression, respectively, which can significantly improve the performance and simplify the training process. Without any bells and whistles, PolarMask achieves 32.9% in mask mAP with single-model and single-scale training/testing on the challenging COCO dataset.For the first time, we show that the complexity of instance segmentation, in terms of both design and computation complexity, can be the same as bounding box object detection and this much simpler and flexible instance segmentation framework can achieve competitive accuracy. We hope that the proposed PolarMask framework can serve as a fundamental and strong baseline for single shot instance segmentation task. Code is available at: github.com/xieenze/PolarMask.

Letting a deep network be aware of the quality of its own predictions is an interesting yet important problem. In the task of instance segmentation, the confidence of instance classification is used as mask quality score in most instance segmentation frameworks. However, the mask quality, quantified as the IoU between the instance mask and its ground truth, is usually not well correlated with classification score. In this paper, we study this problem and propose Mask Scoring R-CNN which contains a network block to learn the quality of the predicted instance masks. The proposed network block takes the instance feature and the corresponding predicted mask together to regress the mask IoU. The mask scoring strategy calibrates the misalignment between mask quality and mask score, and improves instance segmentation performance by prioritizing more accurate mask predictions during COCO AP evaluation. By extensive evaluations on the COCO dataset, Mask Scoring R-CNN brings consistent and noticeable gain with different models, and outperforms the state-of-the-art Mask R-CNN. We hope our simple and effective approach will provide a new direction for improving instance segmentation. The source code of our method is available at https:// github.com/zjhuang22/maskscoring_rcnn. * The work was done when Zhaojin Huang was an intern in Horizon Robotics Inc.

视觉变压器（VIT）正在改变对象检测方法的景观。 VIT的自然使用方法是用基于变压器的骨干替换基于CNN的骨干，该主链很简单有效，其价格为推理带来了可观的计算负担。更微妙的用法是DEDR家族，它消除了对物体检测中许多手工设计的组件的需求，但引入了一个解码器，要求超长时间进行融合。结果，基于变压器的对象检测不能在大规模应用中占上风。为了克服这些问题，我们提出了一种新型的无解码器基于完全变压器（DFFT）对象检测器，这是第一次在训练和推理阶段达到高效率。我们通过居中两个切入点来简化反对检测到仅编码单级锚点的密集预测问题：1）消除训练感知的解码器，并利用两个强的编码器来保留单层特征映射预测的准确性； 2）探索具有有限的计算资源的检测任务的低级语义特征。特别是，我们设计了一种新型的轻巧的面向检测的变压器主链，该主链有效地捕获了基于良好的消融研究的丰富语义的低级特征。 MS Coco基准测试的广泛实验表明，DFFT_SMALL的表现优于2.5％AP，计算成本降低28％，$ 10 \ $ 10 \乘以$ 10 \乘以$较少的培训时期。与尖端的基于锚的探测器视网膜相比，DFFT_SMALL获得了超过5.5％的AP增益，同时降低了70％的计算成本。