扩张的卷曲广泛用于深度语义分段模型，因为它们可以扩大过滤器的接收领域而不增加额外的权重，也不牺牲空间分辨率。然而，正如扩张的卷积滤波器在语义上有意义的轮廓上没有关于像素的位置知识，它们可能导致对象边界的模糊预测。另外，虽然扩张过滤器可以扩展其接收领域，但是采样像素的总数保持不变，这通常包括一小部分接收领域的总面积。灵感来自人类视觉系统中的横向抑制（LI）机制，我们提出了具有横向抑制（LI-CONVS）的扩张卷积以克服这些限制。介绍锂机制提高了卷积滤波器对语义对象边界的敏感性。此外，由于LI-DIVS也隐含地考虑从横向禁止的区域中的像素考虑，因此它们还可以以密度刻度提取特征。通过将锂致常规集成到Deeplabv3 +架构中，我们提出了横向抑制的不受欢迎的空间金字塔汇集（Li-Aspp），横向抑制的Mobilenet-V2（Li-MnV2）和横向抑制的Reset（Li-Reset）。在三个基准数据集（Pascal VOC 2012，Celebamask-HQ和Ade20k）的实验结果表明，我们的李氏分割模型越来越突出了所有这些的基线，从而验证了拟议的LI-CONN的有效性和一般性。

In this work we address the task of semantic image segmentation with Deep Learning and make three main contributions that are experimentally shown to have substantial practical merit. First, we highlight convolution with upsampled filters, or 'atrous convolution', as a powerful tool in dense prediction tasks. Atrous convolution allows us to explicitly control the resolution at which feature responses are computed within Deep Convolutional Neural Networks. It also allows us to effectively enlarge the field of view of filters to incorporate larger context without increasing the number of parameters or the amount of computation. Second, we propose atrous spatial pyramid pooling (ASPP) to robustly segment objects at multiple scales. ASPP probes an incoming convolutional feature layer with filters at multiple sampling rates and effective fields-of-views, thus capturing objects as well as image context at multiple scales. Third, we improve the localization of object boundaries by combining methods from DCNNs and probabilistic graphical models. The commonly deployed combination of max-pooling and downsampling in DCNNs achieves invariance but has a toll on localization accuracy. We overcome this by combining the responses at the final DCNN layer with a fully connected Conditional Random Field (CRF), which is shown both qualitatively and quantitatively to improve localization performance. Our proposed "DeepLab" system sets the new state-of-art at the PASCAL VOC-2012 semantic image segmentation task, reaching 79.7% mIOU in the test set, and advances the results on three other datasets: PASCAL-Context, PASCAL-Person-Part, and Cityscapes. All of our code is made publicly available online.

Spatial pyramid pooling module or encode-decoder structure are used in deep neural networks for semantic segmentation task. The former networks are able to encode multi-scale contextual information by probing the incoming features with filters or pooling operations at multiple rates and multiple effective fields-of-view, while the latter networks can capture sharper object boundaries by gradually recovering the spatial information. In this work, we propose to combine the advantages from both methods. Specifically, our proposed model, DeepLabv3+, extends DeepLabv3 by adding a simple yet effective decoder module to refine the segmentation results especially along object boundaries. We further explore the Xception model and apply the depthwise separable convolution to both Atrous Spatial Pyramid Pooling and decoder modules, resulting in a faster and stronger encoder-decoder network. We demonstrate the effectiveness of the proposed model on PASCAL VOC 2012 and Cityscapes datasets, achieving the test set performance of 89.0% and 82.1% without any post-processing. Our paper is accompanied with a publicly available reference implementation of the proposed models in Tensorflow at https: //github.com/tensorflow/models/tree/master/research/deeplab.

语义分割是计算机视觉中的关键任务之一，它是为图像中的每个像素分配类别标签。尽管最近取得了重大进展，但大多数现有方法仍然遇到两个具有挑战性的问题：1）图像中的物体和东西的大小可能非常多样化，要求将多规模特征纳入完全卷积网络（FCN）； 2）由于卷积网络的固有弱点，很难分类靠近物体/物体的边界的像素。为了解决第一个问题，我们提出了一个新的多受感受性现场模块（MRFM），明确考虑了多尺度功能。对于第二期，我们设计了一个边缘感知损失，可有效区分对象/物体的边界。通过这两种设计，我们的多种接收场网络在两个广泛使用的语义分割基准数据集上实现了新的最先进的结果。具体来说，我们在CityScapes数据集上实现了83.0的平均值，在Pascal VOC2012数据集中达到了88.4的平均值。

Recent work has made significant progress in improving spatial resolution for pixelwise labeling with Fully Convolutional Network (FCN) framework by employing Dilated/Atrous convolution, utilizing multi-scale features and refining boundaries. In this paper, we explore the impact of global contextual information in semantic segmentation by introducing the Context Encoding Module, which captures the semantic context of scenes and selectively highlights class-dependent featuremaps. The proposed Context Encoding Module significantly improves semantic segmentation results with only marginal extra computation cost over FCN. Our approach has achieved new state-of-theart results 51.7% mIoU on PASCAL-Context, 85.9% mIoU on PASCAL VOC 2012. Our single model achieves a final score of 0.5567 on ADE20K test set, which surpasses the winning entry of COCO-Place Challenge 2017. In addition, we also explore how the Context Encoding Module can improve the feature representation of relatively shallow networks for the image classification on CIFAR-10 dataset. Our 14 layer network has achieved an error rate of 3.45%, which is comparable with state-of-the-art approaches with over 10× more layers. The source code for the complete system are publicly available 1 .

Image segmentation is a key topic in image processing and computer vision with applications such as scene understanding, medical image analysis, robotic perception, video surveillance, augmented reality, and image compression, among many others. Various algorithms for image segmentation have been developed in the literature. Recently, due to the success of deep learning models in a wide range of vision applications, there has been a substantial amount of works aimed at developing image segmentation approaches using deep learning models. In this survey, we provide a comprehensive review of the literature at the time of this writing, covering a broad spectrum of pioneering works for semantic and instance-level segmentation, including fully convolutional pixel-labeling networks, encoder-decoder architectures, multi-scale and pyramid based approaches, recurrent networks, visual attention models, and generative models in adversarial settings. We investigate the similarity, strengths and challenges of these deep learning models, examine the most widely used datasets, report performances, and discuss promising future research directions in this area.

Australian Centre for Robotic Vision {guosheng.lin;anton.milan;chunhua.shen;

Deep Convolutional Neural Networks (DCNNs) have recently shown state of the art performance in high level vision tasks, such as image classification and object detection. This work brings together methods from DCNNs and probabilistic graphical models for addressing the task of pixel-level classification (also called "semantic image segmentation"). We show that responses at the final layer of DCNNs are not sufficiently localized for accurate object segmentation. This is due to the very invariance properties that make DCNNs good for high level tasks. We overcome this poor localization property of deep networks by combining the responses at the final DCNN layer with a fully connected Conditional Random Field (CRF). Qualitatively, our "DeepLab" system is able to localize segment boundaries at a level of accuracy which is beyond previous methods. Quantitatively, our method sets the new state-of-art at the PASCAL VOC-2012 semantic image segmentation task, reaching 71.6% IOU accuracy in the test set. We show how these results can be obtained efficiently: Careful network re-purposing and a novel application of the 'hole' algorithm from the wavelet community allow dense computation of neural net responses at 8 frames per second on a modern GPU.

我们展示了一个下一代神经网络架构，马赛克，用于移动设备上的高效和准确的语义图像分割。MOSAIC是通过各种移动硬件平台使用常用的神经操作设计，以灵活地部署各种移动平台。利用简单的非对称编码器 - 解码器结构，该解码器结构由有效的多尺度上下文编码器和轻量级混合解码器组成，以从聚合信息中恢复空间细节，Mosaic在平衡准确度和计算成本的同时实现了新的最先进的性能。基于搜索的分类网络，马赛克部署在定制的特征提取骨架顶部，达到目前行业标准MLPerf型号和最先进的架构，达到5％的绝对精度增益。

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/.

语义分割是自主车辆了解周围场景的关键技术。当代模型的吸引力表现通常以牺牲重计算和冗长的推理时间为代价，这对于自行车来说是无法忍受的。在低分辨率图像上使用轻量级架构（编码器 - 解码器或双路）或推理，最近的方法实现了非常快的场景解析，即使在单个1080TI GPU上以100多件FPS运行。然而，这些实时方法与基于扩张骨架的模型之间的性能仍有显着差距。为了解决这个问题，我们提出了一家专门为实时语义细分设计的高效底座。所提出的深层双分辨率网络（DDRNET）由两个深部分支组成，之间进行多个双边融合。此外，我们设计了一个名为Deep聚合金字塔池（DAPPM）的新上下文信息提取器，以基于低分辨率特征映射放大有效的接收字段和熔丝多尺度上下文。我们的方法在城市景观和Camvid数据集上的准确性和速度之间实现了新的最先进的权衡。特别是，在单一的2080Ti GPU上，DDRNET-23-Slim在Camvid测试组上的Citycapes试验组102 FPS上的102 FPS，74.7％Miou。通过广泛使用的测试增强，我们的方法优于最先进的模型，需要计算得多。 CODES和培训的型号在线提供。

Incorporating multi-scale features in fully convolutional neural networks (FCNs) has been a key element to achieving state-of-the-art performance on semantic image segmentation. One common way to extract multi-scale features is to feed multiple resized input images to a shared deep network and then merge the resulting features for pixelwise classification. In this work, we propose an attention mechanism that learns to softly weight the multi-scale features at each pixel location. We adapt a state-of-the-art semantic image segmentation model, which we jointly train with multi-scale input images and the attention model. The proposed attention model not only outperforms averageand max-pooling, but allows us to diagnostically visualize the importance of features at different positions and scales. Moreover, we show that adding extra supervision to the output at each scale is essential to achieving excellent performance when merging multi-scale features. We demonstrate the effectiveness of our model with extensive experiments on three challenging datasets, including PASCAL-Person-Part,

Scene parsing is challenging for unrestricted open vocabulary and diverse scenes. In this paper, we exploit the capability of global context information by different-regionbased context aggregation through our pyramid pooling module together with the proposed pyramid scene parsing network (PSPNet). Our global prior representation is effective to produce good quality results on the scene parsing task, while PSPNet provides a superior framework for pixellevel prediction. The proposed approach achieves state-ofthe-art performance on various datasets. It came first in Im-ageNet scene parsing challenge 2016, PASCAL VOC 2012 benchmark and Cityscapes benchmark. A single PSPNet yields the new record of mIoU accuracy 85.4% on PASCAL VOC 2012 and accuracy 80.2% on Cityscapes.

One of recent trends [31,32,14] in network architecture design is stacking small filters (e.g., 1x1 or 3x3) in the entire network because the stacked small filters is more efficient than a large kernel, given the same computational complexity. However, in the field of semantic segmentation, where we need to perform dense per-pixel prediction, we find that the large kernel (and effective receptive field) plays an important role when we have to perform the classification and localization tasks simultaneously. Following our design principle, we propose a Global Convolutional Network to address both the classification and localization issues for the semantic segmentation. We also suggest a residual-based boundary refinement to further refine the object boundaries. Our approach achieves state-of-art performance on two public benchmarks and significantly outperforms previous results, 82.2% (vs 80.2%) on PASCAL VOC 2012 dataset and 76.9% (vs 71.8%) on Cityscapes dataset.

由于长距离依赖性建模的能力，变压器在各种自然语言处理和计算机视觉任务中表现出令人印象深刻的性能。最近的进展证明，将这种变压器与基于CNN的语义图像分割模型相结合非常有前途。然而，目前还没有很好地研究了纯变压器的方法如何实现图像分割。在这项工作中，我们探索了语义图像分割的新框架，它是基于编码器 - 解码器的完全变压器网络（FTN）。具体地，我们首先提出金字塔组变压器（PGT）作为逐步学习分层特征的编码器，同时降低标准视觉变压器（VIT）的计算复杂性。然后，我们将特征金字塔变换器（FPT）提出了来自PGT编码器的多电平进行语义图像分割的多级别的语义级别和空间级信息。令人惊讶的是，这种简单的基线可以在多个具有挑战性的语义细分和面部解析基准上实现更好的结果，包括帕斯卡背景，ADE20K，Cocostuff和Celebamask-HQ。源代码将在https://github.com/br -dl/paddlevit上发布。

We notice information flow in convolutional neural networks is restricted inside local neighborhood regions due to the physical design of convolutional filters, which limits the overall understanding of complex scenes. In this paper, we propose the point-wise spatial attention network (PSANet) to relax the local neighborhood constraint. Each position on the feature map is connected to all the other ones through a self-adaptively learned attention mask. Moreover, information propagation in bi-direction for scene parsing is enabled. Information at other positions can be collected to help the prediction of the current position and vice versa, information at the current position can be distributed to assist the prediction of other ones. Our proposed approach achieves top performance on various competitive scene parsing datasets, including ADE20K, PASCAL VOC 2012 and Cityscapes, demonstrating its effectiveness and generality.

共同出现的视觉模式使上下文聚集成为语义分割的重要范式。现有的研究重点是建模图像中的上下文，同时忽略图像以下相应类别的有价值的语义。为此，我们提出了一个新颖的软采矿上下文信息，超出了名为McIbi ++的图像范式，以进一步提高像素级表示。具体来说，我们首先设置了动态更新的内存模块，以存储各种类别的数据集级别的分布信息，然后利用信息在网络转发过程中产生数据集级别类别表示。之后，我们为每个像素表示形式生成一个类概率分布，并以类概率分布作为权重进行数据集级上下文聚合。最后，使用汇总的数据集级别和传统的图像级上下文信息来增强原始像素表示。此外，在推论阶段，我们还设计了一种粗到最新的迭代推理策略，以进一步提高分割结果。 MCIBI ++可以轻松地纳入现有的分割框架中，并带来一致的性能改进。此外，MCIBI ++可以扩展到视频语义分割框架中，比基线进行了大量改进。配备MCIBI ++，我们在七个具有挑战性的图像或视频语义分段基准测试中实现了最先进的性能。

视觉表示学习是解决各种视力问题的关键。依靠开创性的网格结构先验，卷积神经网络（CNN）已成为大多数深视觉模型的事实上的标准架构。例如，经典的语义分割方法通常采用带有编码器编码器体系结构的完全横向卷积网络（FCN）。编码器逐渐减少了空间分辨率，并通过更大的接受场来学习更多抽象的视觉概念。由于上下文建模对于分割至关重要，因此最新的努力一直集中在通过扩张（即极度）卷积或插入注意力模块来增加接受场。但是，基于FCN的体系结构保持不变。在本文中，我们旨在通过将视觉表示学习作为序列到序列预测任务来提供替代观点。具体而言，我们部署纯变压器以将图像编码为一系列贴片，而无需局部卷积和分辨率减少。通过在变压器的每一层中建立的全球环境，可以学习更强大的视觉表示形式，以更好地解决视力任务。特别是，我们的细分模型（称为分割变压器（SETR））在ADE20K上擅长（50.28％MIOU，这是提交当天测试排行榜中的第一个位置），Pascal环境（55.83％MIOU），并在CityScapes上达到竞争成果。此外，我们制定了一个分层局部全球（HLG）变压器的家族，其特征是窗户内的本地关注和跨窗户的全球性专注于层次结构和金字塔架构。广泛的实验表明，我们的方法在各种视觉识别任务（例如，图像分类，对象检测和实例分割和语义分割）上实现了吸引力的性能。

Semantic image segmentation is a basic street scene understanding task in autonomous driving, where each pixel in a high resolution image is categorized into a set of semantic labels. Unlike other scenarios, objects in autonomous driving scene exhibit very large scale changes, which poses great challenges for high-level feature representation in a sense that multi-scale information must be correctly encoded. To remedy this problem, atrous convolution [14] was introduced to generate features with larger receptive fields without sacrificing spatial resolution. Built upon atrous convolution, Atrous Spatial Pyramid Pooling (ASPP) [2] was proposed to concatenate multiple atrous-convolved features using different dilation rates into a final feature representation. Although ASPP is able to generate multi-scale features, we argue the feature resolution in the scale-axis is not dense enough for the autonomous driving scenario. To this end, we propose Densely connected Atrous Spatial Pyramid Pooling (DenseASPP), which connects a set of atrous convolutional layers in a dense way, such that it generates multi-scale features that not only cover a larger scale range, but also cover that scale range densely, without significantly increasing the model size. We evaluate DenseASPP on the street scene benchmark Cityscapes [4] and achieve state-of-the-art performance.

跨不同层的特征的聚合信息是密集预测模型的基本操作。尽管表现力有限，但功能级联占主导地位聚合运营的选择。在本文中，我们引入了细分特征聚合（AFA），以融合不同的网络层，具有更具表现力的非线性操作。 AFA利用空间和渠道注意，以计算层激活的加权平均值。灵感来自神经体积渲染，我们将AFA扩展到规模空间渲染（SSR），以执行多尺度预测的后期融合。 AFA适用于各种现有网络设计。我们的实验表明了对挑战性的语义细分基准，包括城市景观，BDD100K和Mapillary Vistas的一致而显着的改进，可忽略不计的计算和参数开销。特别是，AFA改善了深层聚集（DLA）模型在城市景观上的近6％Miou的性能。我们的实验分析表明，AFA学会逐步改进分割地图并改善边界细节，导致新的最先进结果对BSDS500和NYUDV2上的边界检测基准。在http://vis.xyz/pub/dla-afa上提供代码和视频资源。