由于许多安全性系统(例如手术机器人和自动驾驶汽车)在不稳定的环境中运行,具有传感器噪声和不完整的数据,因此希望对象探测器将本地化不确定性考虑在内。但是,基于锚的对象检测的现有不确定性估计方法存在几个局限性。 1)它们对具有不同特征和尺度的异质对象性质的不确定性进行建模,例如位置(中心点)和尺度(宽度,高度),这可能很难估算。 2)它们将框偏移型为高斯分布,这与遵循Dirac Delta分布的地面真相边界框不兼容。 3)由于基于锚的方法对锚定超参数敏感,因此它们的定位不确定性也可能对选择超参数的选择高度敏感。为了应对这些局限性,我们提出了一种称为UAD的新定位不确定性估计方法,用于无锚对象检测。我们的方法捕获了均匀的四个方向(左,右,顶部,底部)的四个方向的不确定性,因此它可以判断哪个方向不确定,并在[0,1]中提供不确定性的定量值。为了实现这种不确定性估计,我们设计了一种新的不确定性损失,负功率对数可能性损失,以通过加权其IOU加权可能性损失来衡量本地化不确定性,从而减轻了模型错误指定问题。此外,我们提出了反映分类评分的估计不确定性的不确定性感知局灶性损失。可可数据集的实验结果表明,我们的方法在不牺牲计算效率的情况下显着提高了最高1.8点的FCO。
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We propose a fully convolutional one-stage object detector (FCOS) to solve object detection in a per-pixel prediction fashion, analogue to semantic segmentation. Almost all state-of-the-art object detectors such as RetinaNet, SSD, YOLOv3, and Faster R-CNN rely on pre-defined anchor boxes. In contrast, our proposed detector FCOS is anchor box free, as well as proposal free. By eliminating the predefined set of anchor boxes, FCOS completely avoids the complicated computation related to anchor boxes such as calculating overlapping during training. More importantly, we also avoid all hyper-parameters related to anchor boxes, which are often very sensitive to the final detection performance. With the only post-processing non-maximum suppression (NMS), FCOS with ResNeXt-64x4d-101 achieves 44.7% in AP with single-model and single-scale testing, surpassing previous one-stage detectors with the advantage of being much simpler. For the first time, we demonstrate a much simpler and flexible detection framework achieving improved detection accuracy. We hope that the proposed FCOS framework can serve as a simple and strong alternative for many other instance-level tasks. Code is available at:tinyurl.com/FCOSv1
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Recent one-stage object detectors follow a per-pixel prediction approach that predicts both the object category scores and boundary positions from every single grid location. However, the most suitable positions for inferring different targets, i.e., the object category and boundaries, are generally different. Predicting all these targets from the same grid location thus may lead to sub-optimal results. In this paper, we analyze the suitable inference positions for object category and boundaries, and propose a prediction-target-decoupled detector named PDNet to establish a more flexible detection paradigm. Our PDNet with the prediction decoupling mechanism encodes different targets separately in different locations. A learnable prediction collection module is devised with two sets of dynamic points, i.e., dynamic boundary points and semantic points, to collect and aggregate the predictions from the favorable regions for localization and classification. We adopt a two-step strategy to learn these dynamic point positions, where the prior positions are estimated for different targets first, and the network further predicts residual offsets to the positions with better perceptions of the object properties. Extensive experiments on the MS COCO benchmark demonstrate the effectiveness and efficiency of our method. With a single ResNeXt-64x4d-101-DCN as the backbone, our detector achieves 50.1 AP with single-scale testing, which outperforms the state-of-the-art methods by an appreciable margin under the same experimental settings.Moreover, our detector is highly efficient as a one-stage framework. Our code is public at https://github.com/yangli18/PDNet.
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我们提出对象盒,这是一种新颖的单阶段锚定且高度可推广的对象检测方法。与现有的基于锚固的探测器和无锚的探测器相反,它们更偏向于其标签分配中的特定对象量表,我们仅将对象中心位置用作正样本,并在不同的特征级别中平均处理所有对象,而不论对象'尺寸或形状。具体而言,我们的标签分配策略将对象中心位置视为形状和尺寸不足的锚定,并以无锚固的方式锚定,并允许学习每个对象的所有尺度。为了支持这一点,我们将新的回归目标定义为从中心单元位置的两个角到边界框的四个侧面的距离。此外,为了处理比例变化的对象,我们提出了一个量身定制的损失来处理不同尺寸的盒子。结果,我们提出的对象检测器不需要在数据集中调整任何依赖数据集的超参数。我们在MS-Coco 2017和Pascal VOC 2012数据集上评估了我们的方法,并将我们的结果与最先进的方法进行比较。我们观察到,与先前的作品相比,对象盒的性能优惠。此外,我们执行严格的消融实验来评估我们方法的不同组成部分。我们的代码可在以下网址提供:https://github.com/mohsenzand/objectbox。
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无锚的检测器基本上将对象检测作为密集的分类和回归。对于流行的无锚检测器,通常是引入单个预测分支来估计本地化的质量。当我们深入研究分类和质量估计的实践时,会观察到以下不一致之处。首先,对于某些分配了完全不同标签的相邻样品,训练有素的模型将产生相似的分类分数。这违反了训练目标并导致绩效退化。其次,发现检测到具有较高信心的边界框与相应的地面真相具有较小的重叠。准确的局部边界框将被非最大抑制(NMS)过程中的精确量抑制。为了解决不一致问题,提出了动态平滑标签分配(DSLA)方法。基于最初在FCO中开发的中心概念,提出了平稳的分配策略。在[0,1]中将标签平滑至连续值,以在正样品和负样品之间稳定过渡。联合(IOU)在训练过程中会动态预测,并与平滑标签结合。分配动态平滑标签以监督分类分支。在这样的监督下,质量估计分支自然合并为分类分支,这简化了无锚探测器的体系结构。全面的实验是在MS Coco基准上进行的。已经证明,DSLA可以通过减轻上述无锚固探测器的不一致来显着提高检测准确性。我们的代码在https://github.com/yonghaohe/dsla上发布。
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Object detection has been dominated by anchor-based detectors for several years. Recently, anchor-free detectors have become popular due to the proposal of FPN and Focal Loss. In this paper, we first point out that the essential difference between anchor-based and anchor-free detection is actually how to define positive and negative training samples, which leads to the performance gap between them. If they adopt the same definition of positive and negative samples during training, there is no obvious difference in the final performance, no matter regressing from a box or a point. This shows that how to select positive and negative training samples is important for current object detectors. Then, we propose an Adaptive Training Sample Selection (ATSS) to automatically select positive and negative samples according to statistical characteristics of object. It significantly improves the performance of anchor-based and anchor-free detectors and bridges the gap between them. Finally, we discuss the necessity of tiling multiple anchors per location on the image to detect objects. Extensive experiments conducted on MS COCO support our aforementioned analysis and conclusions. With the newly introduced ATSS, we improve stateof-the-art detectors by a large margin to 50.7% AP without introducing any overhead. The code is available at https://github.com/sfzhang15/ATSS.
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物体检测在计算机视觉中取得了巨大的进步。具有外观降级的小物体检测是一个突出的挑战,特别是对于鸟瞰观察。为了收集足够的阳性/阴性样本进行启发式训练,大多数物体探测器预设区域锚,以便将交叉联盟(iou)计算在地面判处符号数据上。在这种情况下,小物体经常被遗弃或误标定。在本文中,我们提出了一种有效的动态增强锚(DEA)网络,用于构建新颖的训练样本发生器。与其他最先进的技术不同,所提出的网络利用样品鉴别器来实现基于锚的单元和无锚单元之间的交互式样本筛选,以产生符合资格的样本。此外,通过基于保守的基于锚的推理方案的多任务联合训练增强了所提出的模型的性能,同时降低计算复杂性。所提出的方案支持定向和水平对象检测任务。对两个具有挑战性的空中基准(即,DotA和HRSC2016)的广泛实验表明,我们的方法以适度推理速度和用于训练的计算开销的准确性实现最先进的性能。在DotA上,我们的DEA-NET与ROI变压器的基线集成了0.40%平均平均精度(MAP)的先进方法,以便用较弱的骨干网(Resnet-101 VS Resnet-152)和3.08%平均 - 平均精度(MAP),具有相同骨干网的水平对象检测。此外,我们的DEA网与重新排列的基线一体化实现最先进的性能80.37%。在HRSC2016上,它仅使用3个水平锚点超过1.1%的最佳型号。
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Single-frame InfraRed Small Target (SIRST) detection has been a challenging task due to a lack of inherent characteristics, imprecise bounding box regression, a scarcity of real-world datasets, and sensitive localization evaluation. In this paper, we propose a comprehensive solution to these challenges. First, we find that the existing anchor-free label assignment method is prone to mislabeling small targets as background, leading to their omission by detectors. To overcome this issue, we propose an all-scale pseudo-box-based label assignment scheme that relaxes the constraints on scale and decouples the spatial assignment from the size of the ground-truth target. Second, motivated by the structured prior of feature pyramids, we introduce the one-stage cascade refinement network (OSCAR), which uses the high-level head as soft proposals for the low-level refinement head. This allows OSCAR to process the same target in a cascade coarse-to-fine manner. Finally, we present a new research benchmark for infrared small target detection, consisting of the SIRST-V2 dataset of real-world, high-resolution single-frame targets, the normalized contrast evaluation metric, and the DeepInfrared toolkit for detection. We conduct extensive ablation studies to evaluate the components of OSCAR and compare its performance to state-of-the-art model-driven and data-driven methods on the SIRST-V2 benchmark. Our results demonstrate that a top-down cascade refinement framework can improve the accuracy of infrared small target detection without sacrificing efficiency. The DeepInfrared toolkit, dataset, and trained models are available at https://github.com/YimianDai/open-deepinfrared to advance further research in this field.
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由遮挡,信号丢失或手动注释错误引起的3D边界框的地面真相注释的固有歧义可能会使训练过程中的深3D对象检测器混淆,从而使检测准确性恶化。但是,现有方法在某种程度上忽略了此类问题,并将标签视为确定性。在本文中,我们提出了GLENET,这是一个从条件变异自动编码器改编的生成标签不确定性估计框架,以建模典型的3D对象与其潜在的潜在基边界框之间具有潜在变量的一对一关系。 Glenet产生的标签不确定性是一个插件模块,可以方便地集成到现有的深3D检测器中,以构建概率检测器并监督本地化不确定性的学习。此外,我们提出了概率探测器中的不确定性质量估计量架构,以指导对IOU分支的培训,并预测了本地化不确定性。我们将提出的方法纳入各种流行的3D检测器中,并观察到它们的性能显着提高到Waymo Open DataSet和Kitti数据集中的当前最新技术。
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Modern object detectors rely heavily on rectangular bounding boxes, such as anchors, proposals and the final predictions, to represent objects at various recognition stages. The bounding box is convenient to use but provides only a coarse localization of objects and leads to a correspondingly coarse extraction of object features. In this paper, we present RepPoints (representative points), a new finer representation of objects as a set of sample points useful for both localization and recognition. Given ground truth localization and recognition targets for training, RepPoints learn to automatically arrange themselves in a manner that bounds the spatial extent of an object and indicates semantically significant local areas. They furthermore do not require the use of anchors to sample a space of bounding boxes. We show that an anchor-free object detector based on RepPoints can be as effective as the state-of-the-art anchor-based detection methods, with 46.5 AP and 67.4 AP 50 on the COCO test-dev detection benchmark, using ResNet-101 model. Code is available at https://github.com/microsoft/RepPoints.
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大多数最先进的实例级人类解析模型都采用了两阶段的基于锚的探测器,因此无法避免启发式锚盒设计和像素级别缺乏分析。为了解决这两个问题,我们设计了一个实例级人类解析网络,该网络在像素级别上无锚固且可解决。它由两个简单的子网络组成:一个用于边界框预测的无锚检测头和一个用于人体分割的边缘引导解析头。无锚探测器的头继承了像素样的优点,并有效地避免了对象检测应用中证明的超参数的敏感性。通过引入部分感知的边界线索,边缘引导的解析头能够将相邻的人类部分与彼此区分开,最多可在一个人类实例中,甚至重叠的实例。同时,利用了精炼的头部整合盒子级别的分数和部分分析质量,以提高解析结果的质量。在两个多个人类解析数据集(即CIHP和LV-MHP-V2.0)和一个视频实例级人类解析数据集(即VIP)上进行实验,表明我们的方法实现了超过全球级别和实例级别的性能最新的一阶段自上而下的替代方案。
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复杂的水下环境为物体检测带来了新的挑战,例如未平衡的光条件,低对比度,阻塞和水生生物的模仿。在这种情况下,水下相机捕获的物体将变得模糊,并且通用探测器通常会在这些模糊的物体上失败。这项工作旨在从两个角度解决问题:不确定性建模和艰难的例子采矿。我们提出了一个名为Boosting R-CNN的两阶段水下检测器,该检测器包括三个关键组件。首先,提出了一个名为RetinArpn的新区域建议网络,该网络提供了高质量的建议,并考虑了对象和IOU预测,以确定对象事先概率的不确定性。其次,引入了概率推理管道,以结合第一阶段的先验不确定性和第二阶段分类评分,以模拟最终检测分数。最后,我们提出了一种名为Boosting Reweighting的新的硬示例挖掘方法。具体而言,当区域提案网络误认为样品的对象的事先概率时,提高重新加权将在训练过程中增加R-CNN头部样品的分类损失,同时减少具有准确估计的先验的简易样品丢失。因此,可以在第二阶段获得强大的检测头。在推理阶段,R-CNN具有纠正第一阶段的误差以提高性能的能力。在两个水下数据集和两个通用对象检测数据集上进行的全面实验证明了我们方法的有效性和鲁棒性。
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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.
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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。
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检测微小的物体是一个非常具有挑战性的问题,因为一个小物体只包含几个像素的大小。我们证明,由于缺乏外观信息,最新的检测器不会对微小物体产生令人满意的结果。我们的主要观察结果是,基于联合(IOU)的相交(例如IOU本身及其扩展)对微小物体的位置偏差非常敏感,并且在基于锚固的检测器中使用时会大大恶化检测性能。为了减轻这一点,我们提出了使用Wasserstein距离进行微小对象检测的新评估度量。具体而言,我们首先将边界框建模为2D高斯分布,然后提出一个新的公制称为标准化的瓦斯汀距离(NWD),以通过相应的高斯分布来计算它们之间的相似性。提出的NWD度量可以轻松地嵌入分配中,非最大抑制作用以及任何基于锚固的检测器的损耗函数,以替换常用的IOU度量。我们在新的数据集上评估了我们的度量,以用于微小对象检测(AI-TOD),其中平均对象大小比现有对象检测数据集小得多。广泛的实验表明,在配备NWD指标时,我们的方法的性能比标准的微调基线高6.7 AP点,并且比最先进的竞争对手高6.0 AP点。代码可在以下网址提供:https://github.com/jwwangchn/nwd。
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标签分配在现代对象检测模型中起着重要作用。检测模型可能会通过不同的标签分配策略产生完全不同的性能。对于基于锚的检测模型,锚点及其相应的地面真实边界框之间的IO(与联合的交点)是关键要素,因为正面样品和负样品除以IOU阈值。早期对象探测器仅利用所有训练样本的固定阈值,而最近的检测算法则基于基于IOUS到地面真相框的分布而着重于自适应阈值。在本文中,我们介绍了一种简单的同时有效的方法,可以根据预测的培训状态动态执行标签分配。通过在标签分配中引入预测,选择了更高的地面真相对象的高质量样本作为正样本,这可以减少分类得分和IOU分数之间的差异,并生成更高质量的边界框。我们的方法显示了使用自适应标签分配算法和这些正面样本的下限框损失的检测模型的性能的改进,这表明将更多具有较高质量预测盒的样品选择为阳性。
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知识蒸馏(KD)目睹了其在物体检测中学习紧凑型号的强大能力。以前的KD方法用于对象检测主要是侧重于模仿仿地区内的深度特征,而不是模仿分类登录,而不是蒸馏定位信息的低效率。在本文中,通过重新制定本地化的知识蒸馏过程,我们提出了一种新的本地化蒸馏(LD)方法,可以有效地将老师的本地化知识转移给学生。此外,我们还启发式介绍了有价值的本地化区域的概念,可以帮助选择性地蒸馏某个地区的语义和本地化知识。第一次结合这两个新组件,我们显示Logit Mimicing可以优于特征模仿和本地化知识蒸馏比蒸馏对象探测器的语义知识更为重要和有效。我们的蒸馏方案简单,有效,可以很容易地应用于不同的致密物体探测器。实验表明,我们的LD可以将GFOCal-Reset-50的AP得分提升,单一规模的1 $ \ Times $培训计划从Coco基准测试中的40.1到42.1,没有任何牺牲品推断速度。我们的源代码和培训的型号在https://github.com/hikaritju/ld公开提供
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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。
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In object detection, keypoint-based approaches often suffer a large number of incorrect object bounding boxes, arguably due to the lack of an additional look into the cropped regions. This paper presents an efficient solution which explores the visual patterns within each cropped region with minimal costs. We build our framework upon a representative one-stage keypoint-based detector named Corner-Net. Our approach, named CenterNet, detects each object as a triplet, rather than a pair, of keypoints, which improves both precision and recall. Accordingly, we design two customized modules named cascade corner pooling and center pooling, which play the roles of enriching information collected by both top-left and bottom-right corners and providing more recognizable information at the central regions, respectively. On the MS-COCO dataset, CenterNet achieves an AP of 47.0%, which outperforms all existing one-stage detectors by at least 4.9%. Meanwhile, with a faster inference speed, CenterNet demonstrates quite comparable performance to the top-ranked two-stage detectors. Code is available at https://github.com/ Duankaiwen/CenterNet.
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共享连接和自动驾驶汽车(CAV)之间的信息从根本上改善了自动驾驶的协作对象检测的性能。但是,由于实际挑战,骑士仍然存在不确定性的对象检测,这将影响自动驾驶中的后来模块,例如计划和控制。因此,不确定性定量对于诸如CAV等安全至关重要系统至关重要。我们的工作是第一个估计协作对象检测的不确定性的工作。我们提出了一种新型的不确定性量化方法,称为Double-M量化,该方法通过直接建模到边界框的每个角落的多变量高斯分布来定制移动块引导(MBB)算法。我们的方法基于离线双M训练过程,通过一个推理通过了一个推理,同时捕获了认知的不确定性和差异不确定性。它可以与不同的协作对象检测器一起使用。通过对综合协作感知数据集进行的实验,我们表明,与最先进的不确定性量化方法相比,我们的双M方法在不确定性评分和3%的准确度上提高了4倍以上。我们的代码在https://coperception.github.io/double-m-quantification上公开。
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