Current state-of-the-art convolutional architectures for object detection are manually designed. Here we aim to learn a better architecture of feature pyramid network for object detection. We adopt Neural Architecture Search and discover a new feature pyramid architecture in a novel scalable search space covering all cross-scale connections. The discovered architecture, named NAS-FPN, consists of a combination of top-down and bottom-up connections to fuse features across scales. NAS-FPN, combined with various backbone models in the RetinaNet framework, achieves better accuracy and latency tradeoff compared to state-ofthe-art object detection models. NAS-FPN improves mobile detection accuracy by 2 AP compared to state-of-the-art SS-DLite with MobileNetV2 model in [32] and achieves 48.3 AP which surpasses Mask R-CNN [10] detection accuracy with less computation time.

Model efficiency has become increasingly important in computer vision. In this paper, we systematically study neural network architecture design choices for object detection and propose several key optimizations to improve efficiency. First, we propose a weighted bi-directional feature pyramid network (BiFPN), which allows easy and fast multiscale feature fusion; Second, we propose a compound scaling method that uniformly scales the resolution, depth, and width for all backbone, feature network, and box/class prediction networks at the same time. Based on these optimizations and better backbones, we have developed a new family of object detectors, called EfficientDet, which consistently achieve much better efficiency than prior art across a wide spectrum of resource constraints. In particular, with singlemodel and single-scale, our EfficientDet-D7 achieves stateof-the-art 55.1 AP on COCO test-dev with 77M parameters and 410B FLOPs 1 , being 4x -9x smaller and using 13x -42x fewer FLOPs than previous detectors. Code is available at https://github.com/google/automl/tree/ master/efficientdet.

Developing neural network image classification models often requires significant architecture engineering. In this paper, we study a method to learn the model architectures directly on the dataset of interest. As this approach is expensive when the dataset is large, we propose to search for an architectural building block on a small dataset and then transfer the block to a larger dataset. The key contribution of this work is the design of a new search space (which we call the "NASNet search space") which enables transferability. In our experiments, we search for the best convolutional layer (or "cell") on the CIFAR-10 dataset and then apply this cell to the ImageNet dataset by stacking together more copies of this cell, each with their own parameters to design a convolutional architecture, which we name a "NASNet architecture". We also introduce a new regularization technique called ScheduledDropPath that significantly improves generalization in the NASNet models. On CIFAR-10 itself, a NASNet found by our method achieves 2.4% error rate, which is state-of-the-art. Although the cell is not searched for directly on ImageNet, a NASNet constructed from the best cell achieves, among the published works, state-of-the-art accuracy of 82.7% top-1 and 96.2% top-5 on ImageNet. Our model is 1.2% better in top-1 accuracy than the best human-invented architectures while having 9 billion fewer FLOPS -a reduction of 28% in computational demand from the previous state-of-the-art model. When evaluated at different levels of computational cost, accuracies of NASNets exceed those of the state-of-the-art human-designed models. For instance, a small version of NASNet also achieves 74% top-1 accuracy, which is 3.1% better than equivalently-sized, state-of-the-art models for mobile platforms. Finally, the image features learned from image classification are generically useful and can be transferred to other computer vision problems. On the task of object detection, the learned features by NASNet used with the Faster-RCNN framework surpass state-of-the-art by 4.0% achieving 43.1% mAP on the COCO dataset.

锥体网络是多尺度对象检测的标准方法。当前对特征金字塔网络的研究通常采用层连接来从特征层次结构的某些级别收集特征，并且不考虑它们之间的显着差异。我们提出了一个更好的特征金字塔网络的体系结构，称为选择性多尺度学习（SMSL），以解决此问题。SMSL高效且泛滥，可以将其集成到单阶段和两阶段检测器中以提高检测性能，几乎没有额外的推理成本。视网膜与SMSL的结合获得了可可数据集的AP（从39.1 \％到40.9 \％）的1.8 \％改进。与SMSL集成时，两阶段探测器的AP可以提高1.0 \％。

由于卷积在提取物体的局部上下文中，在过去十年中，对象检测在过去十年中取得了重大进展。但是，对象的尺度是多样的，当前卷积只能处理单尺度输入。因此，传统卷积具有固定接收场在处理这种规模差异问题方面的能力受到限制。多尺度功能表示已被证明是缓解规模差异问题的有效方法。最近的研究主要与某些量表或各个尺度的总体特征采用部分联系，并专注于整个量表的全球信息。但是，跨空间和深度维度的信息被忽略了。受此启发，我们提出了多尺度卷积（MSCONV）来解决此问题。同时考虑到量表，空间和深度信息，MSCONV能够更全面地处理多尺度输入。 MSCONV是有效的，并且在计算上是有效的，只有少量计算成本增加。对于大多数单阶段对象探测器，在检测头中用MSCONV代替传统的卷积可以带来AP的2.5 \％改进（在Coco 2017数据集上），只有3 \％的拖鞋增加了。 MSCONV对于两阶段对象探测器也具有灵活性和有效性。当扩展到主流两阶段对象检测器时，MSCONV的AP可以提高3.0 \％。我们在单尺度测试下的最佳模型在Coco 2017上实现了48.9 \％AP，\ textit {test-dev} Split，它超过了许多最新方法。

在传统的对象检测框架中，从图像识别模型继承的骨干体提取了深层特征，然后颈部模块融合了这些潜在特征，以在不同的尺度上捕获信息。由于对象检测的分辨率比图像识别大得多，因此骨干的计算成本通常主导了总推断成本。这种沉重的背部设计范式主要是由于历史遗产将图像识别模型传输到对象检测时，而不是端到端的优化设计以进行对象检测。在这项工作中，我们表明这种范式确实导致了亚最佳对象检测模型。为此，我们提出了一种新型的重颈范式，长颈鹿，这是一个类似长颈鹿的网络，用于有效的对象检测。长颈鹿使用极轻的骨干和非常深的颈部模块，可同时同时在不同的空间尺度以及不同级别的潜在语义之间进行密集的信息交换。该设计范式允许检测器即使在网络的早期阶段，也可以在相同的优先级处理高级语义信息和低级空间信息，从而使其在检测任务中更有效。对多个流行对象检测基准的数值评估表明，长颈鹿在广泛的资源约束中始终优于先前的SOTA模型。源代码可在https://github.com/jyqi/giraffedet上获得。

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.

Designing convolutional neural networks (CNN) for mobile devices is challenging because mobile models need to be small and fast, yet still accurate. Although significant efforts have been dedicated to design and improve mobile CNNs on all dimensions, it is very difficult to manually balance these trade-offs when there are so many architectural possibilities to consider. In this paper, we propose an automated mobile neural architecture search (MNAS) approach, which explicitly incorporate model latency into the main objective so that the search can identify a model that achieves a good trade-off between accuracy and latency. Unlike previous work, where latency is considered via another, often inaccurate proxy (e.g., FLOPS), our approach directly measures real-world inference latency by executing the model on mobile phones. To further strike the right balance between flexibility and search space size, we propose a novel factorized hierarchical search space that encourages layer diversity throughout the network. Experimental results show that our approach consistently outperforms state-of-the-art mobile CNN models across multiple vision tasks. On the ImageNet classification task, our MnasNet achieves 75.2% top-1 accuracy with 78ms latency on a Pixel phone, which is 1.8× faster than MobileNetV2 [29] with 0.5% higher accuracy and 2.3× faster than NASNet [36] with 1.2% higher accuracy. Our MnasNet also achieves better mAP quality than MobileNets for COCO object detection. Code is at https://github.com/tensorflow/tpu/ tree/master/models/official/mnasnet.

大多数对象检测框架都使用最初设计用于图像分类的主链体系结构，通常在Imagenet上具有预训练的参数。但是，图像分类和对象检测本质上是不同的任务，并且不能保证分类的最佳主链也适用于对象检测。最近的神经体系结构搜索（NAS）研究表明，自动设计专门用于对象检测的骨干有助于提高整体准确性。在本文中，我们引入了一种神经体系结构适应方法，该方法可以优化给定的主链以进行检测目的，同时仍允许使用预训练的参数。我们建议除了每个块的输出通道尺寸外，还通过搜索特定操作和层数来调整微体系结构。重要的是要找到最佳的通道深度，因为它极大地影响了特征表示功能和计算成本。我们使用搜索的主链进行对象检测进行实验，并证明我们的主链在可可数据集上的手动设计和搜索的最新骨干均优于手动设计和搜索的骨干。

本文提出了平行残留的双融合特征金字塔网络（PRB-FPN），以快速准确地单光对象检测。特征金字塔（FP）在最近的视觉检测中被广泛使用，但是由于汇总转换，FP的自上而下的途径无法保留准确的定位。随着使用更多层的更深骨干，FP的优势被削弱了。此外，它不能同时准确地检测到小物体。为了解决这些问题，我们提出了一种新的并行FP结构，具有双向（自上而下和自下而上）的融合以及相关的改进，以保留高质量的特征以进行准确定位。我们提供以下设计改进：（1）具有自下而上的融合模块（BFM）的平行分歧FP结构，以高精度立即检测小物体和大对象。 （2）串联和重组（CORE）模块为特征融合提供了自下而上的途径，该途径导致双向融合FP，可以从低层特征图中恢复丢失的信息。 （3）进一步纯化核心功能以保留更丰富的上下文信息。自上而下和自下而上的途径中的这种核心净化只能在几次迭代中完成。 （4）将残留设计添加到核心中，导致了一个新的重核模块，该模块可以轻松训练和集成，并具有更深入或更轻的骨架。所提出的网络可在UAVDT17和MS COCO数据集上实现最新性能。代码可在https://github.com/pingyang1117/prbnet_pytorch上找到。

We propose a new method for learning the structure of convolutional neural networks (CNNs) that is more efficient than recent state-of-the-art methods based on reinforcement learning and evolutionary algorithms. Our approach uses a sequential model-based optimization (SMBO) strategy, in which we search for structures in order of increasing complexity, while simultaneously learning a surrogate model to guide the search through structure space. Direct comparison under the same search space shows that our method is up to 5 times more efficient than the RL method of Zoph et al. (2018) in terms of number of models evaluated, and 8 times faster in terms of total compute. The structures we discover in this way achieve state of the art classification accuracies on CIFAR-10 and ImageNet.

Recently, Neural architecture search has achieved great success on classification tasks for mobile devices. The backbone network for object detection is usually obtained on the image classification task. However, the architecture which is searched through the classification task is sub-optimal because of the gap between the task of image and object detection. As while work focuses on backbone network architecture search for mobile device object detection is limited, mainly because the backbone always requires expensive ImageNet pre-training. Accordingly, it is necessary to study the approach of network architecture search for mobile device object detection without expensive pre-training. In this work, we propose a mobile object detection backbone network architecture search algorithm which is a kind of evolutionary optimized method based on non-dominated sorting for NAS scenarios. It can quickly search to obtain the backbone network architecture within certain constraints. It better solves the problem of suboptimal linear combination accuracy and computational cost. The proposed approach can search the backbone networks with different depths, widths, or expansion sizes via a technique of weight mapping, making it possible to use NAS for mobile devices detection tasks a lot more efficiently. In our experiments, we verify the effectiveness of the proposed approach on YoloX-Lite, a lightweight version of the target detection framework. Under similar computational complexity, the accuracy of the backbone network architecture we search for is 2.0% mAP higher than MobileDet. Our improved backbone network can reduce the computational effort while improving the accuracy of the object detection network. To prove its effectiveness, a series of ablation studies have been carried out and the working mechanism has been analyzed in detail.

神经结构搜索（NAS）已被广泛采用设计准确，高效的图像分类模型。但是，将NAS应用于新的计算机愿景任务仍然需要大量的努力。这是因为1）以前的NAS研究已经过度优先考虑图像分类，同时在很大程度上忽略了其他任务; 2）许多NAS工作侧重于优化特定于任务特定的组件，这些组件不能有利地转移到其他任务; 3）现有的NAS方法通常被设计为“Proxyless”，需要大量努力与每个新任务的培训管道集成。为了解决这些挑战，我们提出了FBNetv5，这是一个NAS框架，可以在各种视觉任务中寻找神经架构，以降低计算成本和人力努力。具体而言，我们设计1）一个简单但包容性和可转换的搜索空间; 2）用目标任务培训管道解开的多址搜索过程; 3）一种算法，用于同时搜索具有计算成本不可知的多个任务的架构到任务数。我们评估所提出的FBNetv5目标三个基本视觉任务 - 图像分类，对象检测和语义分割。 FBNETV5在单一搜索中搜索的模型在所有三个任务中都表现优于先前的议定书 - 现有技术：图像分类（例如，与FBNetv3相比，在与FBNetv3相比的同一拖鞋下的1 + 1.3％Imageet Top-1精度。 （例如，+ 1.8％较高的Ade20k Val。Miou比SegFormer为3.6倍的拖鞋），对象检测（例如，+ 1.1％Coco Val。与yolox相比，拖鞋的1.2倍的地图。

最近，已经成功地应用于各种遥感图像（RSI）识别任务的大量基于深度学习的方法。然而，RSI字段中深度学习方法的大多数现有进步严重依赖于手动设计的骨干网络提取的特征，这严重阻碍了由于RSI的复杂性以及先前知识的限制而受到深度学习模型的潜力。在本文中，我们研究了RSI识别任务中的骨干架构的新设计范式，包括场景分类，陆地覆盖分类和对象检测。提出了一种基于权重共享策略和进化算法的一拍架构搜索框架，称为RSBNet，其中包括三个阶段：首先，在层面搜索空间中构造的超空网是在自组装的大型中预先磨削 - 基于集合单路径培训策略进行缩放RSI数据集。接下来，预先培训的SuperNet通过可切换识别模块配备不同的识别头，并分别在目标数据集上进行微调，以获取特定于任务特定的超网络。最后，我们根据没有任何网络训练的进化算法，搜索最佳骨干架构进行不同识别任务。对于不同识别任务的五个基准数据集进行了广泛的实验，结果显示了所提出的搜索范例的有效性，并证明搜索后的骨干能够灵活地调整不同的RSI识别任务并实现令人印象深刻的性能。

在对象检测模型中，检测骨干机消耗超过一半的整体推理成本。最近的研究试图通过在神经结构搜索（NAS）的帮助下优化骨干架构来降低这一成本。然而，对象检测的现有NAS方法需要数百至数千个GPU小时的搜索，使它们在快节奏的研究和开发中不切实际。在这项工作中，我们提出了一种新的零射NAS方法来解决这个问题。所提出的方法，命名为Zendet，在不训练网络参数的情况下自动设计有效的检测骨干网，从而降低了架构设计成本，几乎归零但提供了最先进的（SOTA）性能。在引擎盖下，Zendet最大化了检测骨干的差分熵，导致对象检测的更好的特征提取器，在相同的计算预算下。在仅为全自动设计的一个GPU日之后，Zendet在多个检测基准数据集上创新了SOTA检测骨干，具有很少的人为干预。与Reset-50个骨干相比，Zendet在Map中使用相同数量的拖波/参数时更好地+ 2.0％，并且在同一地图上的NVIDIA V100速度快1.54倍。稍后将发布代码和预先训练的型号。

We present the next generation of MobileNets based on a combination of complementary search techniques as well as a novel architecture design. MobileNetV3 is tuned to mobile phone CPUs through a combination of hardwareaware network architecture search (NAS) complemented by the NetAdapt algorithm and then subsequently improved through novel architecture advances. This paper starts the exploration of how automated search algorithms and network design can work together to harness complementary approaches improving the overall state of the art. Through this process we create two new MobileNet models for release: MobileNetV3-Large and MobileNetV3-Small which are targeted for high and low resource use cases. These models are then adapted and applied to the tasks of object detection and semantic segmentation. For the task of semantic segmentation (or any dense pixel prediction), we propose a new efficient segmentation decoder Lite Reduced Atrous Spatial Pyramid Pooling (LR-ASPP). We achieve new state of the art results for mobile classification, detection and segmentation. MobileNetV3-Large is 3.2% more accurate on ImageNet classification while reducing latency by 20% compared to MobileNetV2. MobileNetV3-Small is 6.6% more accurate compared to a MobileNetV2 model with comparable latency. MobileNetV3-Large detection is over 25% faster at roughly the same accuracy as Mo-bileNetV2 on COCO detection. MobileNetV3-Large LR-ASPP is 34% faster than MobileNetV2 R-ASPP at similar accuracy for Cityscapes segmentation.

Recently, Neural Architecture Search (NAS) has successfully identified neural network architectures that exceed human designed ones on large-scale image classification. In this paper, we study NAS for semantic image segmentation. Existing works often focus on searching the repeatable cell structure, while hand-designing the outer network structure that controls the spatial resolution changes. This choice simplifies the search space, but becomes increasingly problematic for dense image prediction which exhibits a lot more network level architectural variations. Therefore, we propose to search the network level structure in addition to the cell level structure, which forms a hierarchical architecture search space. We present a network level search space that includes many popular designs, and develop a formulation that allows efficient gradient-based architecture search (3 P100 GPU days on Cityscapes images). We demonstrate the effectiveness of the proposed method on the challenging Cityscapes, PASCAL VOC 2012, and ADE20K datasets. Auto-DeepLab, our architecture searched specifically for semantic image segmentation, attains state-of-the-art performance without any ImageNet pretraining. 1 * Work done while an intern at Google.

In this report, we present a fast and accurate object detection method dubbed DAMO-YOLO, which achieves higher performance than the state-of-the-art YOLO series. DAMO-YOLO is extended from YOLO with some new technologies, including Neural Architecture Search (NAS), efficient Reparameterized Generalized-FPN (RepGFPN), a lightweight head with AlignedOTA label assignment, and distillation enhancement. In particular, we use MAE-NAS, a method guided by the principle of maximum entropy, to search our detection backbone under the constraints of low latency and high performance, producing ResNet-like / CSP-like structures with spatial pyramid pooling and focus modules. In the design of necks and heads, we follow the rule of "large neck, small head". We import Generalized-FPN with accelerated queen-fusion to build the detector neck and upgrade its CSPNet with efficient layer aggregation networks (ELAN) and reparameterization. Then we investigate how detector head size affects detection performance and find that a heavy neck with only one task projection layer would yield better results. In addition, AlignedOTA is proposed to solve the misalignment problem in label assignment. And a distillation schema is introduced to improve performance to a higher level. Based on these new techs, we build a suite of models at various scales to meet the needs of different scenarios, i.e., DAMO-YOLO-Tiny/Small/Medium. They can achieve 43.0/46.8/50.0 mAPs on COCO with the latency of 2.78/3.83/5.62 ms on T4 GPUs respectively. The code is available at https://github.com/tinyvision/damo-yolo.

现代的高性能语义分割方法采用沉重的主链和扩张的卷积来提取相关特征。尽管使用上下文和语义信息提取功能对于分割任务至关重要，但它为实时应用程序带来了内存足迹和高计算成本。本文提出了一种新模型，以实现实时道路场景语义细分的准确性/速度之间的权衡。具体来说，我们提出了一个名为“比例吸引的条带引导特征金字塔网络”（s \ textsuperscript {2} -fpn）的轻巧模型。我们的网络由三个主要模块组成：注意金字塔融合（APF）模块，比例吸引条带注意模块（SSAM）和全局特征Upsample（GFU）模块。 APF采用了注意力机制来学习判别性多尺度特征，并有助于缩小不同级别之间的语义差距。 APF使用量表感知的关注来用垂直剥离操作编码全局上下文，并建模长期依赖性，这有助于将像素与类似的语义标签相关联。此外，APF还采用频道重新加权块（CRB）来强调频道功能。最后，S \ TextSuperScript {2} -fpn的解码器然后采用GFU，该GFU用于融合APF和编码器的功能。已经对两个具有挑战性的语义分割基准进行了广泛的实验，这表明我们的方法通过不同的模型设置实现了更好的准确性/速度权衡。提出的模型已在CityScapes Dataset上实现了76.2 \％miou/87.3fps，77.4 \％miou/67fps和77.8 \％miou/30.5fps，以及69.6 \％miou，71.0 miou，71.0 \％miou，和74.2 \％\％\％\％\％\％。 miou在Camvid数据集上。这项工作的代码将在\ url {https://github.com/mohamedac29/s2-fpn提供。

卷积神经网络（CNN）在许多计算机视觉任务（例如图像分类和对象检测）中取得了巨大的成功。但是，他们的性能在更艰巨的任务上迅速降低，因为图像是低分辨率或物体很小的。在本文中，我们指出，这根源于现有CNN体系结构中的有缺陷但常见的设计，即使用稳固的卷积和/或汇总层，这导致丢失细粒度的信息和学习较低有效的功能表示形式。为此，我们提出了一个新的CNN构建块，称为SPD-CONV，代替每个稳定的卷积层和每个池层（从而完全消除它们）。 SPD-CONV由一个对深度（SPD）层的组成，然后是非构造卷积（CORV）层，并且可以在大多数（如果不是全部）CNN体系结构中应用。我们在两个最具代表性的计算机视觉任务下解释了这种新设计：对象检测和图像分类。然后，我们通过将SPD-CONV应用于Yolov5和Resnet来创建新的CNN体​​系结构，并从经验上表明，我们的方法显着优于最先进的深度学习模型，尤其是在具有低分辨率图像和小物体的更艰巨的任务上。我们已经在https://github.com/labsaint/spd-conv上开源代码。