这项工作的目的是探索如何有效有效地将预训练的基础模型适应图像语义分割的各种下游任务。常规方法通常为每个特定数据集微调整个网络,并且存储这些网络的大量参数是繁重的。最近的一些作品试图将一些可训练的参数插入冷冻网络中,以学习有效调整的视觉提示。但是,这些作品显着修改了标准模块的原始结构,使其在许多现有的高速推理设备上无法使用,其中标准模块及其参数已嵌入。为了促进基于及时的语义细分,我们提出了一个新颖的阶段间及时匹配的框架,该框架保持基础模型的原始结构,同时自适应地生成视觉提示,以适应以任务为导向的调整。具体而言,首先将预训练的模型分为多个阶段,其参数被冷冻并共享所有语义分割任务。然后将称为语义意识的提示匹配器的轻巧模块在两个阶段之间介绍给层次上的插值,以在临时语义图的指导下学习每个特定任务的合理提示。这样,我们可以更好地刺激对冷冻模型的预训练的知识,以有效地学习下游数据集的语义概念。在五个基准上进行的广泛实验表明,所提出的方法可以实现参数效率和性能效率之间的有希望的权衡。
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在计算机视觉中,微调是利用预训练的视觉模型来执行下游任务的事实上的方法。但是,由于采用参数效率低下的全局更新并严重依赖于高质量的下游数据,因此在实践中部署它是非常具有挑战性的。最近,基于及时的学习添加了与任务相关的提示,以使下游任务适应预训练的模型,从而极大地提高了许多自然语言下游任务的性能。在这项工作中,我们扩展了这种显着的转移能力,从迅速的愿景模型中受益,以替代微调。为此,我们提出了参数有效的及时调整(亲调整),以使冷冻视觉模型适应各种下游视觉任务。实行调整的关键是基于及时的调整,即学习特定于任务的视觉提示,以使用预先训练的模型冷冻的下游输入图像。通过仅培训一些其他参数,它可以在基于CNN和基于变压器的各种架构上工作。广泛的实验证据表明,在广泛的视觉任务和场景中,主张表现优于微调,包括图像分类(通用对象,类失衡,图像腐败,对抗性稳定性和分布范围内的概括)和密集的预测任务例如对象检测和语义分割。
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ous vision tasks without convolutions, where it can be used as a direct replacement for CNN backbones. (3) We validate PVT through extensive experiments, showing that it boosts the performance of many downstream tasks, including object detection, instance and semantic segmentation. For example, with a comparable number of parameters, PVT+RetinaNet achieves 40.4 AP on the COCO dataset, surpassing ResNet50+RetinNet (36.3 AP) by 4.1 absolute AP (see Figure 2). We hope that PVT could serve as an alternative and useful backbone for pixel-level predictions and facilitate future research.
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最近的进展表明,使用对比图像文本对的大规模预训练可以是从自然语言监督的高质量视觉表演学习的有前途的替代方案。从更广泛的监督来源受益,这种新的范例展示了对下游分类任务和数据集的令人印象深刻的可转移性。然而,从图像文本对中学习的知识转移到更复杂的密集预测任务的问题几乎没有访问过。在这项工作中,我们通过隐式和明确地利用来自剪辑的预先训练的知识来提出了一种新的密集预测框架。具体地,我们将剪辑中的原始图像文本匹配问题转换为像素文本匹配问题,并使用像素文本分数图来指导致密预测模型的学习。通过进一步使用图像中的上下文信息来提示语言模型,我们能够促进我们的模型来更好地利用预先接受训练的知识。我们的方法是模型 - 不可行的,它可以应用于任意密集的预测系统和各种预先训练的视觉底座,包括夹模型和想象成预先训练的模型。广泛的实验证明了我们对语义分割,对象检测和实例分段任务的方法的卓越性能。代码可在https://github.com/raoyongming/denseclip获得
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当前的Modus Operandi在改编预训练的模型中涉及更新所有骨干参数,即,完整的微调。本文介绍了视觉及时调整(VPT),作为视觉中大规模变压器模型的全面微调的有效替代方案。VPT从最近有效地调整大型语言模型的最新进展中汲取灵感,在输入空间中仅引入了少量的可训练参数(少于模型参数),同时保持模型骨架冻结。通过对各种下游识别任务的广泛实验,我们表明VPT与其他参数有效调整协议相比获得了显着的性能增长。最重要的是,在许多情况下,VPT甚至在模型能力和培训数据量表的许多情况下都胜过全面的微调,同时降低了每任务的存储成本。
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Transformers have made remarkable progress towards modeling long-range dependencies within the medical image analysis domain. However, current transformer-based models suffer from several disadvantages: (1) existing methods fail to capture the important features of the images due to the naive tokenization scheme; (2) the models suffer from information loss because they only consider single-scale feature representations; and (3) the segmentation label maps generated by the models are not accurate enough without considering rich semantic contexts and anatomical textures. In this work, we present CASTformer, a novel type of adversarial transformers, for 2D medical image segmentation. First, we take advantage of the pyramid structure to construct multi-scale representations and handle multi-scale variations. We then design a novel class-aware transformer module to better learn the discriminative regions of objects with semantic structures. Lastly, we utilize an adversarial training strategy that boosts segmentation accuracy and correspondingly allows a transformer-based discriminator to capture high-level semantically correlated contents and low-level anatomical features. Our experiments demonstrate that CASTformer dramatically outperforms previous state-of-the-art transformer-based approaches on three benchmarks, obtaining 2.54%-5.88% absolute improvements in Dice over previous models. Further qualitative experiments provide a more detailed picture of the model's inner workings, shed light on the challenges in improved transparency, and demonstrate that transfer learning can greatly improve performance and reduce the size of medical image datasets in training, making CASTformer a strong starting point for downstream medical image analysis tasks.
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为了同时朝着对多个下游任务的整体理解,需要提取具有更好可传递性的功能。尽管许多最新的自我监管的预训练方法在普遍的预处理前范式下在各种视觉任务上取得了令人印象深刻的表现,但它们对多任务学习方案的概括能力尚待探索。在本文中,我们在三个下游任务上进行了广泛研究各种类型的自我监督方法的转移性能,例如Moco和Simc​​lr,包括语义细分,可驱动的区域细分和交通对象检测,在大规模驾驶数据集中BDD100K。我们出人意料地发现,他们的表现是最佳的甚至落后于单任务基线的滞后,这可能是由于训练目标和建筑设计的区别在于预处理范式。为了克服这一难题,并避免重新设计资源密集的预培训阶段,我们提出了一种简单而有效的预处理 - 适应性 - 赛范围,用于一般的多任务培训,可以有效地适应现行预审预周态的模型没有增加培训开销。在自适应阶段,我们利用可学习的多尺度适配器来动态调整由多任务目标监督的预验证的模型权重,同时使经过预告片的知识未经触及。此外,我们将视觉语言预训练模型剪辑视为对预处理 - 适应 - 最终范式的强烈补充,并提出了一个名为LV-Adapter的新型适配器,该适配器通过任务特定的提示将语言先验纳入了多任务的模型中和视觉和文本特征之间的对齐。
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Transformer-based models have been widely demonstrated to be successful in computer vision tasks by modelling long-range dependencies and capturing global representations. However, they are often dominated by features of large patterns leading to the loss of local details (e.g., boundaries and small objects), which are critical in medical image segmentation. To alleviate this problem, we propose a Dual-Aggregation Transformer Network called DuAT, which is characterized by two innovative designs, namely, the Global-to-Local Spatial Aggregation (GLSA) and Selective Boundary Aggregation (SBA) modules. The GLSA has the ability to aggregate and represent both global and local spatial features, which are beneficial for locating large and small objects, respectively. The SBA module is used to aggregate the boundary characteristic from low-level features and semantic information from high-level features for better preserving boundary details and locating the re-calibration objects. Extensive experiments in six benchmark datasets demonstrate that our proposed model outperforms state-of-the-art methods in the segmentation of skin lesion images, and polyps in colonoscopy images. In addition, our approach is more robust than existing methods in various challenging situations such as small object segmentation and ambiguous object boundaries.
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Existing fine-tuning methods either tune all parameters of the pre-trained model (full fine-tuning), which is not efficient, or only tune the last linear layer (linear probing), which suffers a significant accuracy drop compared to the full fine-tuning. In this paper, we propose a new parameter-efficient fine-tuning method termed as SSF, representing that researchers only need to Scale and Shift the deep Features extracted by a pre-trained model to catch up with the performance of full fine-tuning. In this way, SSF also surprisingly outperforms other parameter-efficient fine-tuning approaches even with a smaller number of tunable parameters. Furthermore, different from some existing parameter-efficient fine-tuning methods (e.g., Adapter or VPT) that introduce the extra parameters and computational cost in the training and inference stages, SSF only adds learnable parameters during the training stage, and these additional parameters can be merged into the original pre-trained model weights via re-parameterization in the inference phase. With the proposed SSF, our model obtains 2.46% (90.72% vs. 88.54%) and 11.48% (73.10% vs. 65.57%) performance improvement on FGVC and VTAB-1k in terms of Top-1 accuracy compared to the full fine-tuning but only fine-tuning about 0.3M parameters. We also conduct amounts of experiments in various model families (CNNs, Transformers, and MLPs) and datasets. Results on 26 image classification datasets in total and 3 robustness & out-of-distribution datasets show the effectiveness of SSF. Code is available at https://github.com/dongzelian/SSF.
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冻结预训练的主链已成为标准范式,以避免在几次分段中过度拟合。在本文中,我们重新考虑范式并探索一个新的制度:{\ em对骨干中的一小部分参数}进行微调。我们提出了一种解决过度拟合问题的解决方案,从而使学习新颖班级的模型概括更好。我们的方法通过奇异值分解(SVD)将主链参数分解为三个连续的矩阵,然后{\ em仅微调单数值}并保持其他冻结。上面的设计使模型可以在新颖类中调整特征表示,同时在预先训练的主链中保持语义线索。我们在具有不同骨架的各种几种射击分割方法上评估了{\ em单数值微调(SVF)}方法。我们在Pascal-5 $^i $和Coco-20 $^i $上都获得了最先进的结果。希望这个简单的基准将鼓励研究人员重新考虑骨干微调在几次环境中的作用。源代码和模型将在\ url {https://github.com/syp2ysy/svf}上获得。
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最近,Vision-Language预训练的零拍图像分类已经表现出令人难以置信的成就,即该模型可以对任意类别进行分类而不看到该类别的其他注释图像。然而,目前尚不清楚如何在更广泛的视觉问题上进行零射识别,例如对象检测和语义分割。在本文中,我们通过在现成的预训练的视觉模型,即剪辑上建立零拍语义分割来定位零拍语义分割。很难因为语义分割和剪辑模型在不同的视觉粒度上执行,该语义分段处理在像素上时,而剪辑在图像上执行。为了解决处理粒度的差异,我们拒绝使用普遍的一级FCN基于FCN的框架,并倡导一个两级语义分割框架,其中第一阶段提取一个完全提取的掩模提案和第二阶段利用基于图像的剪辑模型在第一阶段生成的蒙版图像作物上执行零拍分类。我们的实验结果表明,这种简单的框架通过大型利润率超越了先前的最先进:+29.5 Hiou On Pascal VOC 2012 DataSet,+8.9 Hiou On Coco Stuff DataSet。凭借其简单性和强大的表现,我们希望本框架成为促进未来研究的基准。
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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。
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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。
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尽管参数有效调整(PET)方法在自然语言处理(NLP)任务上显示出巨大的潜力,但其有效性仍然对计算机视觉(CV)任务的大规模转向进行了研究。本文提出了Conv-Adapter,这是一种专为CONCNET设计的PET模块。 Conv-Adapter具有轻巧的,可转让的域和架构,不合时宜,并且在不同的任务上具有广义性能。当转移下游任务时,Conv-Adapter将特定于任务的特征调制到主链的中间表示,同时保持预先训练的参数冻结。通过仅引入少量可学习的参数,例如,仅3.5%的RESNET50的完整微调参数,Conv-Adapter优于先前的宠物基线方法,并实现可比性或超过23个分类任务的全面调查的性能。它还在几乎没有分类的情况下表现出卓越的性能,平均利润率为3.39%。除分类外,Conv-Adapter可以推广到检测和细分任务,其参数降低了50%以上,但性能与传统的完整微调相当。
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Vision transformers (ViTs) encoding an image as a sequence of patches bring new paradigms for semantic segmentation.We present an efficient framework of representation separation in local-patch level and global-region level for semantic segmentation with ViTs. It is targeted for the peculiar over-smoothness of ViTs in semantic segmentation, and therefore differs from current popular paradigms of context modeling and most existing related methods reinforcing the advantage of attention. We first deliver the decoupled two-pathway network in which another pathway enhances and passes down local-patch discrepancy complementary to global representations of transformers. We then propose the spatially adaptive separation module to obtain more separate deep representations and the discriminative cross-attention which yields more discriminative region representations through novel auxiliary supervisions. The proposed methods achieve some impressive results: 1) incorporated with large-scale plain ViTs, our methods achieve new state-of-the-art performances on five widely used benchmarks; 2) using masked pre-trained plain ViTs, we achieve 68.9% mIoU on Pascal Context, setting a new record; 3) pyramid ViTs integrated with the decoupled two-pathway network even surpass the well-designed high-resolution ViTs on Cityscapes; 4) the improved representations by our framework have favorable transferability in images with natural corruptions. The codes will be released publicly.
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随着大型预训练的Vison语言模型(如剪辑)的出现,可以通过及时调整来调整可转让表示形式。及时调整试图从存储在预训练的视觉模型的图像和文本编码器中的常识中探索有益信息,以探索下游任务。最近提出的名为“上下文优化”(COP)的方法将一组可学习的向量从语言侧引入文本提示符,而单独调整文本提示符则不会影响图像编码器的计算视觉特征,从而导致了次级优势。在本文中,我们通过学习文本提示并同时为文本和图像编码器提供双重模式提示调整范式。此外,为了使视觉提示更多地集中在目标视觉概念上,我们提出了类感知的视觉及时调整(CAVPT),该调整是通过在模板提示和视觉类别令牌嵌入的语言描述之间进行交叉注意来动态生成的。我们的方法提供了一种新的范式来调整大型预训练的视觉模型,并在8个数据集上进行了广泛的实验结果,证明了该方法的有效性。我们的代码在补充材料中可用。
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Recently, CLIP has been applied to pixel-level zero-shot learning tasks via a two-stage scheme. The general idea is to first generate class-agnostic region proposals and then feed the cropped proposal regions to CLIP to utilize its image-level zero-shot classification capability. While effective, such a scheme requires two image encoders, one for proposal generation and one for CLIP, leading to a complicated pipeline and high computational cost. In this work, we pursue a simpler-and-efficient one-stage solution that directly extends CLIP's zero-shot prediction capability from image to pixel level. Our investigation starts with a straightforward extension as our baseline that generates semantic masks by comparing the similarity between text and patch embeddings extracted from CLIP. However, such a paradigm could heavily overfit the seen classes and fail to generalize to unseen classes. To handle this issue, we propose three simple-but-effective designs and figure out that they can significantly retain the inherent zero-shot capacity of CLIP and improve pixel-level generalization ability. Incorporating those modifications leads to an efficient zero-shot semantic segmentation system called ZegCLIP. Through extensive experiments on three public benchmarks, ZegCLIP demonstrates superior performance, outperforming the state-of-the-art methods by a large margin under both "inductive" and "transductive" zero-shot settings. In addition, compared with the two-stage method, our one-stage ZegCLIP achieves a speedup of about 5 times faster during inference. We release the code at https://github.com/ZiqinZhou66/ZegCLIP.git.
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细颗粒的对象检索旨在学习判别性表示以检索视觉上相似的对象。但是,现有的表现最佳作品通常在语义嵌入空间上施加成对的相似性,以在有限数据方面不断调整整个模型,从而使次优溶液易于收敛。在本文中,我们开发了细粒度的检索提示调整(FRPT),该调整引导了一个冷冻的预训练模型,从样本提示和功能适应的角度从样本提示的角度执行精细颗粒的检索任务。具体而言,FRPT只需要在提示中学习更少的参数和适应性,而不是对整个模型进行微调,从而解决了通过微调整个模型引起的次优溶液的收敛性。从技术上讲,随着样本提示,引入结构扰动提示(SPP)以缩放甚至夸大了一些像素,从而通过内容感知到的不均匀采样操作为类别预测做出了贡献。这样,SPP可以通过在原始预训练期间接近已解决的任务的扰动提示来帮助您的精细颗粒检索任务。此外,提出了特定于类别的意识头并将其视为特征适应,它可以使用实例归一化在预训练模型提取的特征中消除物种差异,因此仅使优化的功能仅包括子类别之间的差异。广泛的实验表明,我们的FRPT具有较少的可学习参数,可以在三个广泛使用的细粒数据集上实现最先进的性能。
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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。
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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.
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