现代有效的卷积神经网络（CNN）始终使用可分开的卷积（DSC）和神经体系结构搜索（NAS）来减少参数数量和计算复杂性。但是网络的一些固有特征被忽略了。受到可视化功能地图和n $ \ times $ n（n $> $ 1）卷积内核的启发，本文介绍了几种准则，以进一步提高参数效率和推理速度。基于这些准则，我们的参数有效的CNN体​​系结构称为\ textit {vgnetg}，比以前的网络更高的准确性和延迟较低，降低了约30％$ \厚度$ 50％的参数。我们的VGNETG-1.0MP在ImageNet分类数据集上具有0.99万参数的67.7％TOP-1准确性和69.2％的TOP-1精度，而参数为114m。此外，我们证明边缘检测器可以通过用固定的边缘检测核代替N $ \ times $ n内核来代替可学习的深度卷积层来混合特征。我们的VGNETF-1.5MP存档64.4％（ - 3.2％）的TOP-1准确性和66.2％（-1.4％）的TOP-1准确性，具有额外的高斯内核。

Deploying convolutional neural networks (CNNs) on embedded devices is difficult due to the limited memory and computation resources. The redundancy in feature maps is an important characteristic of those successful CNNs, but has rarely been investigated in neural architecture design. This paper proposes a novel Ghost module to generate more feature maps from cheap operations. Based on a set of intrinsic feature maps, we apply a series of linear transformations with cheap cost to generate many ghost feature maps that could fully reveal information underlying intrinsic features. The proposed Ghost module can be taken as a plug-and-play component to upgrade existing convolutional neural networks. Ghost bottlenecks are designed to stack Ghost modules, and then the lightweight Ghost-Net can be easily established. Experiments conducted on benchmarks demonstrate that the proposed Ghost module is an impressive alternative of convolution layers in baseline models, and our GhostNet can achieve higher recognition performance (e.g. 75.7% top-1 accuracy) than MobileNetV3 with similar computational cost on the ImageNet ILSVRC-2012 classification dataset. Code is available at https: //github.com/huawei-noah/ghostnet.

由于存储器和计算资源有限，部署在移动设备上的卷积神经网络（CNNS）是困难的。我们的目标是通过利用特征图中的冗余来设计包括CPU和GPU的异构设备的高效神经网络，这很少在神经结构设计中进行了研究。对于类似CPU的设备，我们提出了一种新颖的CPU高效的Ghost（C-Ghost）模块，以生成从廉价操作的更多特征映射。基于一组内在的特征映射，我们使用廉价的成本应用一系列线性变换，以生成许多幽灵特征图，可以完全揭示内在特征的信息。所提出的C-Ghost模块可以作为即插即用组件，以升级现有的卷积神经网络。 C-Ghost瓶颈旨在堆叠C-Ghost模块，然后可以轻松建立轻量级的C-Ghostnet。我们进一步考虑GPU设备的有效网络。在建筑阶段的情况下，不涉及太多的GPU效率（例如，深度明智的卷积），我们建议利用阶段明智的特征冗余来制定GPU高效的幽灵（G-GHOST）阶段结构。舞台中的特征被分成两个部分，其中使用具有较少输出通道的原始块处理第一部分，用于生成内在特征，另一个通过利用阶段明智的冗余来生成廉价的操作。在基准测试上进行的实验证明了所提出的C-Ghost模块和G-Ghost阶段的有效性。 C-Ghostnet和G-Ghostnet分别可以分别实现CPU和GPU的准确性和延迟的最佳权衡。代码可在https://github.com/huawei-noah/cv-backbones获得。

In standard Convolutional Neural Networks (CNNs), the receptive fields of artificial neurons in each layer are designed to share the same size. It is well-known in the neuroscience community that the receptive field size of visual cortical neurons are modulated by the stimulus, which has been rarely considered in constructing CNNs. We propose a dynamic selection mechanism in CNNs that allows each neuron to adaptively adjust its receptive field size based on multiple scales of input information. A building block called Selective Kernel (SK) unit is designed, in which multiple branches with different kernel sizes are fused using softmax attention that is guided by the information in these branches. Different attentions on these branches yield different sizes of the effective receptive fields of neurons in the fusion layer. Multiple SK units are stacked to a deep network termed Selective Kernel Networks (SKNets). On the ImageNet and CIFAR benchmarks, we empirically show that SKNet outperforms the existing state-of-the-art architectures with lower model complexity. Detailed analyses show that the neurons in SKNet can capture target objects with different scales, which verifies the capability of neurons for adaptively adjusting their receptive field sizes according to the input. The code and models are available at https://github.com/implus/SKNet.

Light-weight convolutional neural networks (CNNs) suffer performance degradation as their low computational budgets constrain both the depth (number of convolution layers) and the width (number of channels) of CNNs, resulting in limited representation capability. To address this issue, we present Dynamic Convolution, a new design that increases model complexity without increasing the network depth or width. Instead of using a single convolution kernel per layer, dynamic convolution aggregates multiple parallel convolution kernels dynamically based upon their attentions, which are input dependent. Assembling multiple kernels is not only computationally efficient due to the small kernel size, but also has more representation power since these kernels are aggregated in a non-linear way via attention. By simply using dynamic convolution for the state-ofthe-art architecture MobileNetV3-Small, the top-1 accuracy of ImageNet classification is boosted by 2.9% with only 4% additional FLOPs and 2.9 AP gain is achieved on COCO keypoint detection.

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.

我们提出了一种多移民通道（MGIC）方法，该方法可以解决参数数量相对于标准卷积神经网络（CNN）中的通道数的二次增长。因此，我们的方法解决了CNN中的冗余，这也被轻量级CNN的成功所揭示。轻巧的CNN可以达到与参数较少的标准CNN的可比精度。但是，权重的数量仍然随CNN的宽度四倍地缩放。我们的MGIC体系结构用MGIC对应物代替了每个CNN块，该块利用了小组大小的嵌套分组卷积的层次结构来解决此问题。因此，我们提出的架构相对于网络的宽度线性扩展，同时保留了通道的完整耦合，如标准CNN中。我们对图像分类，分割和点云分类进行的广泛实验表明，将此策略应用于Resnet和MobilenetV3等不同体系结构，可以减少参数的数量，同时获得相似或更好的准确性。

被广泛采用的缩减采样是为了在视觉识别的准确性和延迟之间取得良好的权衡。不幸的是，没有学习常用的合并层，因此无法保留重要信息。作为另一个降低方法，自适应采样权重和与任务相关的过程区域，因此能够更好地保留有用的信息。但是，自适应采样的使用仅限于某些层。在本文中，我们表明，在深神经网络的构件中使用自适应采样可以提高其效率。特别是，我们提出了SSBNET，该SSBNET是通过将采样层反复插入Resnet等现有网络构建的。实验结果表明，所提出的SSBNET可以在ImageNet和可可数据集上实现竞争性图像分类和对象检测性能。例如，SSB-Resnet-RS-200在Imagenet数据集上的精度达到82.6％，比基线RESNET-RS-152高0.6％，具有相似的复杂性。可视化显示了SSBNET在允许不同层专注于不同位置的优势，而消融研究进一步验证了自适应采样比均匀方法的优势。

为了实现不断增长的准确性，通常会开发大型和复杂的神经网络。这样的模型需要高度的计算资源，因此不能在边缘设备上部署。由于它们在几个应用领域的有用性，建立资源有效的通用网络非常感兴趣。在这项工作中，我们努力有效地结合了CNN和变压器模型的优势，并提出了一种新的有效混合体系结构。特别是在EDGENEXT中，我们引入了分裂深度转置注意力（SDTA）编码器，该编码器将输入张量分解为多个通道组，并利用深度旋转以及跨通道维度的自我注意力，以隐含地增加接受场并编码多尺度特征。我们在分类，检测和分割任务上进行的广泛实验揭示了所提出的方法的优点，优于相对较低的计算要求的最先进方法。我们具有130万参数的EDGENEXT模型在Imagenet-1k上达到71.2 \％TOP-1的精度，超过移动设备的绝对增益为2.2 \％，而拖鞋减少了28 \％。此外，我们具有560万参数的EDGENEXT模型在Imagenet-1k上达到了79.4 \％TOP-1的精度。代码和模型可在https://t.ly/_vu9上公开获得。

We introduce an extremely computation-efficient CNN architecture named ShuffleNet, which is designed specially for mobile devices with very limited computing power (e.g., 10-150 MFLOPs). The new architecture utilizes two new operations, pointwise group convolution and channel shuffle, to greatly reduce computation cost while maintaining accuracy. Experiments on ImageNet classification and MS COCO object detection demonstrate the superior performance of ShuffleNet over other structures, e.g. lower top-1 error (absolute 7.8%) than recent MobileNet [12] on Ima-geNet classification task, under the computation budget of 40 MFLOPs. On an ARM-based mobile device, ShuffleNet achieves ∼13× actual speedup over AlexNet while maintaining comparable accuracy.

在每个卷积层中学习一个静态卷积内核是现代卷积神经网络（CNN）的常见训练范式。取而代之的是，动态卷积的最新研究表明，学习$ n $卷积核与输入依赖性注意的线性组合可以显着提高轻重量CNN的准确性，同时保持有效的推断。但是，我们观察到现有的作品endow卷积内核具有通过一个维度（关于卷积内核编号）的动态属性（关于内核空间的卷积内核编号），但其他三个维度（关于空间大小，输入通道号和输出通道编号和输出通道号，每个卷积内核）被忽略。受到这一点的启发，我们提出了Omni维动态卷积（ODCONV），这是一种更普遍而优雅的动态卷积设计，以推进这一研究。 ODCONV利用了一种新型的多维注意机制，采用平行策略来学习沿着任何卷积层的内核空间的所有四个维度学习卷积内核的互补关注。作为定期卷积的倒数替换，可以将ODCONV插入许多CNN架构中。 ImageNet和MS-Coco数据集的广泛实验表明，ODCONV为包括轻量重量和大型的各种盛行的CNN主链带来了可靠的准确性提升，例如3.77％〜5.71％| 1.86％〜3.72％〜3.72％的绝对1个绝对1改进至ImabivLenetV2 | ImageNet数据集上的重新连接家族。有趣的是，由于其功能学习能力的提高，即使具有一个单个内核的ODCONV也可以与具有多个内核的现有动态卷积对应物竞争或超越现有的动态卷积对应物，从而大大降低了额外的参数。此外，ODCONV也优于其他注意模块，用于调节输出特征或卷积重量。

Currently, the neural network architecture design is mostly guided by the indirect metric of computation complexity, i.e., FLOPs. However, the direct metric, e.g., speed, also depends on the other factors such as memory access cost and platform characterics. Thus, this work proposes to evaluate the direct metric on the target platform, beyond only considering FLOPs. Based on a series of controlled experiments, this work derives several practical guidelines for efficient network design. Accordingly, a new architecture is presented, called ShuffleNet V2.Comprehensive ablation experiments verify that our model is the stateof-the-art in terms of speed and accuracy tradeoff.

Recently, channel attention mechanism has demonstrated to offer great potential in improving the performance of deep convolutional neural networks (CNNs). However, most existing methods dedicate to developing more sophisticated attention modules for achieving better performance, which inevitably increase model complexity.To overcome the paradox of performance and complexity trade-off, this paper proposes an Efficient Channel Attention (ECA) module, which only involves a handful of parameters while bringing clear performance gain. By dissecting the channel attention module in SENet, we empirically show avoiding dimensionality reduction is important for learning channel attention, and appropriate cross-channel interaction can preserve performance while significantly decreasing model complexity. Therefore, we propose a local crosschannel interaction strategy without dimensionality reduction, which can be efficiently implemented via 1D convolution. Furthermore, we develop a method to adaptively select kernel size of 1D convolution, determining coverage of local cross-channel interaction. The proposed ECA module is efficient yet effective, e.g., the parameters and computations of our modules against backbone of ResNet50 are 80 vs. 24.37M and 4.7e-4 GFLOPs vs. 3.86 GFLOPs, respectively, and the performance boost is more than 2% in terms of Top-1 accuracy. We extensively evaluate our ECA module on image classification, object detection and instance segmentation with backbones of ResNets and MobileNetV2. The experimental results show our module is more efficient while performing favorably against its counterparts.

We propose a novel antialiasing method to increase shift invariance in convolutional neural networks (CNNs). More precisely, we replace the conventional combination "real-valued convolutions + max pooling" ($\mathbb R$Max) by "complex-valued convolutions + modulus" ($\mathbb C$Mod), which produce stable feature representations for band-pass filters with well-defined orientations. In a recent work, we proved that, for such filters, the two operators yield similar outputs. Therefore, $\mathbb C$Mod can be viewed as a stable alternative to $\mathbb R$Max. To separate band-pass filters from other freely-trained kernels, in this paper, we designed a "twin" architecture based on the dual-tree complex wavelet packet transform, which generates similar outputs as standard CNNs with fewer trainable parameters. In addition to improving stability to small shifts, our experiments on AlexNet and ResNet showed increased prediction accuracy on natural image datasets such as ImageNet and CIFAR10. Furthermore, our approach outperformed recent antialiasing methods based on low-pass filtering by preserving high-frequency information, while reducing memory usage.

Feature reuse has been a key technique in light-weight convolutional neural networks (CNNs) design. Current methods usually utilize a concatenation operator to keep large channel numbers cheaply (thus large network capacity) by reusing feature maps from other layers. Although concatenation is parameters- and FLOPs-free, its computational cost on hardware devices is non-negligible. To address this, this paper provides a new perspective to realize feature reuse via structural re-parameterization technique. A novel hardware-efficient RepGhost module is proposed for implicit feature reuse via re-parameterization, instead of using concatenation operator. Based on the RepGhost module, we develop our efficient RepGhost bottleneck and RepGhostNet. Experiments on ImageNet and COCO benchmarks demonstrate that the proposed RepGhostNet is much more effective and efficient than GhostNet and MobileNetV3 on mobile devices. Specially, our RepGhostNet surpasses GhostNet 0.5x by 2.5% Top-1 accuracy on ImageNet dataset with less parameters and comparable latency on an ARM-based mobile phone.

最近的工作表明，二值化的神经网络（BNN）能够大大降低计算成本和内存占用空间，促进在资源受限设备上进行模型部署。然而，与其全精密对应物相比，BNN患有严重的精度降解。旨在降低这种精度差距的研究已经很大程度上主要集中在具有少量或没有1x1卷积层的特定网络架构上，标准二值化方法不起作用。由于1x1卷积在现代架构的设计中是常见的（例如，Googlenet，Reset，DenSenet），开发一种方法以有效地为BNN进行更广泛采用的方法是至关重要的。在这项工作中，我们提出了一个“弹性链路”（EL）模块，通过自适应地将实值的输入特征自适应地添加到后续卷积输出功能来丰富了BNN内的信息流。所提出的EL模块很容易实现，并且可以与BNN的其他方法结合使用。我们证明将EL添加到BNNS对挑战大规模想象数数据集产生显着改进。例如，我们将二值化resnet26的前1个精度从57.9％提高到64.0％。 EL也有助于培训二值化Mobilenet的趋同，为此实现了56.4％的前1个精度。最后，随着RESTNET的整合，它产生了新的最新的最新性，最新的171.9％的前1个精度。

对象检测是计算机视觉中的重要下游任务。对于车载边缘计算平台，很难实现实时检测要求。而且，由大量可分开的卷积层建立的轻巧模型无法达到足够的精度。我们引入了一种新的轻质卷积技术GSCONV，以减轻模型，但保持准确性。 GSCONV在模型的准确性和速度之间取得了极好的权衡。而且，我们提供了一个设计范式，即纤细的颈部，以实现探测器的更高计算成本效益。在二十多组比较实验中，我们的方法的有效性得到了强有力的证明。特别是，通过我们的方法改善的检测器获得了最先进的结果（例如，与原件相比，在Tesla T4 GPU上以〜100fps的速度为70.9％MAP0.5。代码可从https://github.com/alanli1997/slim-neck-by-gsconv获得。

视觉变压器的最新进展在基于点产生自我注意的新空间建模机制驱动的各种任务中取得了巨大成功。在本文中，我们表明，视觉变压器背后的关键要素，即输入自适应，远程和高阶空间相互作用，也可以通过基于卷积的框架有效地实现。我们介绍了递归封闭式卷积（$ \ textit {g}^\ textit {n} $ conv），该卷积{n} $ conv）与封闭的卷积和递归设计执行高阶空间交互。新操作是高度灵活和可定制的，它与卷积的各种变体兼容，并将自我注意的两阶相互作用扩展到任意订单，而无需引入大量额外的计算。 $ \ textit {g}^\ textit {n} $ conv可以用作插件模块，以改善各种视觉变压器和基于卷积的模型。根据该操作，我们构建了一个名为Hornet的新型通用视觉骨干家族。关于ImageNet分类，可可对象检测和ADE20K语义分割的广泛实验表明，大黄蜂的表现优于Swin变形金刚，并具有相似的整体体系结构和训练配置的明显边距。大黄蜂还显示出对更多训练数据和更大模型大小的有利可伸缩性。除了在视觉编码器中的有效性外，我们还可以将$ \ textit {g}^\ textit {n} $ conv应用于特定于任务的解码器，并始终通过较少的计算来提高密集的预测性能。我们的结果表明，$ \ textIt {g}^\ textit {n} $ conv可以成为视觉建模的新基本模块，可有效结合视觉变形金刚和CNN的优点。代码可从https://github.com/raoyongming/hornet获得

皮肤镜图像中的皮肤病变检测对于通过计算机化设备对皮肤癌的准确和早期诊断至关重要。当前的皮肤病变细分方法在具有挑战性的环境中表现出较差的性能，例如不明显的病变边界，病变和周围区域之间的对比度低，或导致皮肤病变分割的异质背景。为了准确识别邻近区域的病变，我们提出了基于卷积分解的扩张尺度特征融合网络。我们的网络旨在同时提取不同尺度的功能，这些功能是系统地融合的，以更好地检测。提出的模型具有令人满意的精度和效率。进行病变分割的各种实验以及与最新模型的比较。我们提出的模型始终展示最先进的结果。

Representing features at multiple scales is of great importance for numerous vision tasks. Recent advances in backbone convolutional neural networks (CNNs) continually demonstrate stronger multi-scale representation ability, leading to consistent performance gains on a wide range of applications. However, most existing methods represent the multi-scale features in a layerwise manner. In this paper, we propose a novel building block for CNNs, namely Res2Net, by constructing hierarchical residual-like connections within one single residual block. The Res2Net represents multi-scale features at a granular level and increases the range of receptive fields for each network layer. The proposed Res2Net block can be plugged into the state-of-the-art backbone CNN models, e.g., ResNet, ResNeXt, and DLA. We evaluate the Res2Net block on all these models and demonstrate consistent performance gains over baseline models on widely-used datasets, e.g., CIFAR-100 and ImageNet. Further ablation studies and experimental results on representative computer vision tasks, i.e., object detection, class activation mapping, and salient object detection, further verify the superiority of the Res2Net over the state-of-the-art baseline methods. The source code and trained models are available on https://mmcheng.net/res2net/.