多年来，场景文本识别（STR）一直是计算机视觉的积极研究主题。为了解决这个具有挑战性的问题，已经提出了许多创新的方法，并将语言知识纳入STR模型最近已成为一个显着的趋势。在这项工作中，我们首先从视觉变压器（VIT）的最新进展中汲取灵感来构建一个概念上简单而强大的视觉str模型，该模型建立在VIT和胜过以前的现场文本识别的先前最新模型，包括纯视觉模型和语言增强方法。为了整合语言知识，我们进一步提出了一种多粒性预测策略，以隐式方式将信息从语言模式注入模型，即NLP中广泛使用的子字表示（BPE和Wordpiece）被引入输出空间，除了传统的字符级别表示外，不采用独立语言模型（LM）。所得的算法（称为MGP-STR）能够将Str的性能包络提高到更高的水平。具体而言，它的平均识别精度在标准基准上达到93.35％。代码将很快发布。

提出了基于视觉变压器（VLT）的新型场景文本识别器。受NLP领域的Levenshtein Transformer的启发，提出的方法（命名为Levenshtein OCR和Short Levocr）探索了一种自动从裁剪自然图像中自动转录文本内容的替代方法。具体而言，我们将场景文本识别的问题视为迭代序列完善过程。由纯视觉模型产生的初始预测序列被编码并馈送到跨模式变压器中，以与视觉特征相互作用并融合，以逐渐近似地面真理。改进过程是通过两个基本字符级操作完成的：删除和插入，它们是通过模仿学习来学习的，并允许并行解码，动态长度变化和良好的解释性。定量实验清楚地表明，Levocr在标准基准上实现最新性能，定性分析验证了拟议的Levocr算法的有效性和优势。代码将很快发布。

场景文本识别（str）是图像和文本之间的重要桥梁，吸引了丰富的研究关注。虽然卷积神经网络（CNNS）在此任务中取得了显着的进展，但大多数现有工作都需要额外的模块（上下文建模模块）来帮助CNN捕获全局依赖项来解决归纳偏差并加强文本特征之间的关系。最近，该变压器已被提出作为通过自我关注机制的全球背景建模的有希望的网络，但在应用于识别时主要缺点是效率。我们提出了一个1-D拆分来解决复杂性的挑战，并用变压器编码器替换CNN，以减少对上下文建模模块的需求。此外，最近的方法使用冻结的初始嵌入来指导解码器对文本进行解码，导致精度损失。我们建议使用从变压器编码器中学到的学习学习的可读初始嵌入，使其自适应不同的输入图像。最重要的是，我们介绍了一个新颖的文本识别架构，名为基于变压器的文本识别器，其中包含三个阶段（转换，特征提取和预测）组成的初始嵌入指导（TRIG）。广泛的实验表明，我们的方法可以在文本识别基准上实现最先进的。

Scene text spotting is of great importance to the computer vision community due to its wide variety of applications. Recent methods attempt to introduce linguistic knowledge for challenging recognition rather than pure visual classification. However, how to effectively model the linguistic rules in end-to-end deep networks remains a research challenge. In this paper, we argue that the limited capacity of language models comes from 1) implicit language modeling; 2) unidirectional feature representation; and 3) language model with noise input. Correspondingly, we propose an autonomous, bidirectional and iterative ABINet++ for scene text spotting. Firstly, the autonomous suggests enforcing explicitly language modeling by decoupling the recognizer into vision model and language model and blocking gradient flow between both models. Secondly, a novel bidirectional cloze network (BCN) as the language model is proposed based on bidirectional feature representation. Thirdly, we propose an execution manner of iterative correction for the language model which can effectively alleviate the impact of noise input. Finally, to polish ABINet++ in long text recognition, we propose to aggregate horizontal features by embedding Transformer units inside a U-Net, and design a position and content attention module which integrates character order and content to attend to character features precisely. ABINet++ achieves state-of-the-art performance on both scene text recognition and scene text spotting benchmarks, which consistently demonstrates the superiority of our method in various environments especially on low-quality images. Besides, extensive experiments including in English and Chinese also prove that, a text spotter that incorporates our language modeling method can significantly improve its performance both in accuracy and speed compared with commonly used attention-based recognizers.

Transformer is a new kind of neural architecture which encodes the input data as powerful features via the attention mechanism. Basically, the visual transformers first divide the input images into several local patches and then calculate both representations and their relationship. Since natural images are of high complexity with abundant detail and color information, the granularity of the patch dividing is not fine enough for excavating features of objects in different scales and locations. In this paper, we point out that the attention inside these local patches are also essential for building visual transformers with high performance and we explore a new architecture, namely, Transformer iN Transformer (TNT). Specifically, we regard the local patches (e.g., 16×16) as "visual sentences" and present to further divide them into smaller patches (e.g., 4×4) as "visual words". The attention of each word will be calculated with other words in the given visual sentence with negligible computational costs. Features of both words and sentences will be aggregated to enhance the representation ability. Experiments on several benchmarks demonstrate the effectiveness of the proposed TNT architecture, e.g., we achieve an 81.5% top-1 accuracy on the ImageNet, which is about 1.7% higher than that of the state-of-the-art visual transformer with similar computational cost.

文本识别是文档数字化的长期研究问题。现有的方法通常是基于CNN构建的，以用于图像理解，并为Char-Level文本生成而建立RNN。此外，通常需要另一种语言模型来提高整体准确性作为后处理步骤。在本文中，我们提出了一种使用预训练的图像变压器和文本变压器模型（即Trocr）提出的端到端文本识别方法，该模型利用了变压器体系结构，以实现图像理解和文字级级文本生成。TROR模型很简单，但有效，可以通过大规模合成数据进行预训练，并通过人体标记的数据集进行微调。实验表明，TROR模型的表现优于印刷，手写和场景文本识别任务上的当前最新模型。Trocr模型和代码可在\ url {https://aka.ms/trocr}上公开获得。

在这项工作中，我们探索了用于视觉接地的整洁而有效的基于变压器的框架。先前的方法通常解决了视觉接地的核心问题，即具有手动设计的机制，即多模式融合和推理。这样的启发式设计不仅复杂化，而且使模型容易过度拟合特定的数据分布。为了避免这种情况，我们首先提出了TransVG，该TransVG通过变压器建立了多模式的对应关系，并通过直接回归框坐标来定位引用区域。我们从经验上表明，复杂的融合模块可以用具有更高性能的变压器编码层的简单堆栈代替。但是，TransVG中的核心融合变压器是针对Uni-Modal编码器的独立性，因此应在有限的视觉接地数据上从头开始训练，这使得很难优化并导致次优性能。为此，我们进一步介绍了TransVG ++以进行两倍的改进。一方面，我们通过利用Vision Transformer（VIT）进行视觉功能编码来将框架升级到一个纯粹的基于变压器的框架。对于另一个人来说，我们设计了语言有条件的视觉变压器，以去除外部融合模块，并重用Uni-Modal vit进行中间层的视觉融合。我们对五个普遍数据集进行了广泛的实验，并报告一系列最先进的记录。

Scene text recognition (STR) enables computers to recognize and read the text in various real-world scenes. Recent STR models benefit from taking linguistic information in addition to visual cues into consideration. We propose a novel Masked Vision-Language Transformers (MVLT) to capture both the explicit and the implicit linguistic information. Our encoder is a Vision Transformer, and our decoder is a multi-modal Transformer. MVLT is trained in two stages: in the first stage, we design a STR-tailored pretraining method based on a masking strategy; in the second stage, we fine-tune our model and adopt an iterative correction method to improve the performance. MVLT attains superior results compared to state-of-the-art STR models on several benchmarks. Our code and model are available at https://github.com/onealwj/MVLT.

变压器是一种基于关注的编码器解码器架构，彻底改变了自然语言处理领域。灵感来自这一重大成就，最近在将变形式架构调整到计算机视觉（CV）领域的一些开创性作品，这已经证明了他们对各种简历任务的有效性。依靠竞争力的建模能力，与现代卷积神经网络相比在本文中，我们已经为三百不同的视觉变压器进行了全面的审查，用于三个基本的CV任务（分类，检测和分割），提出了根据其动机，结构和使用情况组织这些方法的分类。 。由于培训设置和面向任务的差异，我们还在不同的配置上进行了评估了这些方法，以便于易于和直观的比较而不是各种基准。此外，我们已经揭示了一系列必不可少的，但可能使变压器能够从众多架构中脱颖而出，例如松弛的高级语义嵌入，以弥合视觉和顺序变压器之间的差距。最后，提出了三个未来的未来研究方向进行进一步投资。

The recently developed vision transformer (ViT) has achieved promising results on image classification compared to convolutional neural networks. Inspired by this, in this paper, we study how to learn multi-scale feature representations in transformer models for image classification. To this end, we propose a dual-branch transformer to combine image patches (i.e., tokens in a transformer) of different sizes to produce stronger image features. Our approach processes small-patch and large-patch tokens with two separate branches of different computational complexity and these tokens are then fused purely by attention multiple times to complement each other. Furthermore, to reduce computation, we develop a simple yet effective token fusion module based on cross attention, which uses a single token for each branch as a query to exchange information with other branches. Our proposed cross-attention only requires linear time for both computational and memory complexity instead of quadratic time otherwise. Extensive experiments demonstrate that our approach performs better than or on par with several concurrent works on vision transformer, in addition to efficient CNN models. For example, on the ImageNet1K dataset, with some architectural changes, our approach outperforms the recent DeiT by a large margin of 2% with a small to moderate increase in FLOPs and model parameters. Our source codes and models are available at https://github.com/IBM/CrossViT.

Image segmentation is often ambiguous at the level of individual image patches and requires contextual information to reach label consensus. In this paper we introduce Segmenter, a transformer model for semantic segmentation. In contrast to convolution-based methods, our approach allows to model global context already at the first layer and throughout the network. We build on the recent Vision Transformer (ViT) and extend it to semantic segmentation. To do so, we rely on the output embeddings corresponding to image patches and obtain class labels from these embeddings with a point-wise linear decoder or a mask transformer decoder. We leverage models pre-trained for image classification and show that we can fine-tune them on moderate sized datasets available for semantic segmentation. The linear decoder allows to obtain excellent results already, but the performance can be further improved by a mask transformer generating class masks. We conduct an extensive ablation study to show the impact of the different parameters, in particular the performance is better for large models and small patch sizes. Segmenter attains excellent results for semantic segmentation. It outperforms the state of the art on both ADE20K and Pascal Context datasets and is competitive on Cityscapes.

旨在识别来自子类别的对象的细粒度视觉分类（FGVC）是一个非常具有挑战性的任务，因为固有的微妙级别差异。大多数现有工程主要通过重用骨干网络来提取检测到的歧视区域的特征来解决这个问题。然而，该策略不可避免地使管道复杂化并推动所提出的区域，其中大多数物体的大多数部分未能定位真正重要的部分。最近，视觉变压器（VIT）在传统的分类任务中表现出其强大的表现。变压器的自我关注机制将每个补丁令牌链接到分类令牌。在这项工作中，我们首先评估vit框架在细粒度识别环境中的有效性。然后，由于注意力的强度，可以直观地被认为是令牌重要性的指标，我们进一步提出了一种新颖的部分选择模块，可以应用于我们整合变压器的所有原始注意力的变压器架构进入注意地图，用于指导网络以有效，准确地选择鉴别的图像斑块并计算它们的关系。应用对比损失来扩大混淆类的特征表示之间的距离。我们将基于增强的变压器的模型Transfg命名，并通过在我们实现最先进的绩效的五个流行的细粒度基准测试中进行实验来展示它的价值。提出了更好地理解模型的定性结果。

通过提供语义来改进字符序列，语言知识对现场文本识别带来了很大的好处。然而，由于语言知识已经单独应用于输出序列，因此之前的方法没有充分利用语义来理解文本识别的视觉线索。本文介绍了一种名为多模态文本识别网络（MITRN）的新方法，其能够实现视觉和语义特征之间的相互作用以获得更好的识别性能。具体地，Matrn识别视觉和语义特征对并将空间信息进行编码为语义特征。基于空间编码，通过参考其他模态的相关特征提高了视觉和语义特征。此外，通过隐藏与训练阶段中的角色相关的视觉线程来刺激基质特征将语义特征组合成视觉特征。我们的实验表明，在具有大边缘的七个基准上实现了最先进的表演，而两个方式的天真组合显示了边缘改善。进一步消融研究证明了我们所提出的组件的有效性。我们的实施将公开提供。

Vision Transformers have shown great promise recently for many vision tasks due to the insightful architecture design and attention mechanism. By revisiting the self-attention responses in Transformers, we empirically observe two interesting issues. First, Vision Transformers present a queryirrelevant behavior at deep layers, where the attention maps exhibit nearly consistent contexts in global scope, regardless of the query patch position (also head-irrelevant). Second, the attention maps are intrinsically sparse, few tokens dominate the attention weights; introducing the knowledge from ConvNets would largely smooth the attention and enhance the performance. Motivated by above observations, we generalize self-attention formulation to abstract a queryirrelevant global context directly and further integrate the global context into convolutions. The resulting model, a Fully Convolutional Vision Transformer (i.e., FCViT), purely consists of convolutional layers and firmly inherits the merits of both attention mechanism and convolutions, including dynamic property, weight sharing, and short- and long-range feature modeling, etc. Experimental results demonstrate the effectiveness of FCViT. With less than 14M parameters, our FCViT-S12 outperforms related work ResT-Lite by 3.7% top1 accuracy on ImageNet-1K. When scaling FCViT to larger models, we still perform better than previous state-of-the-art ConvNeXt with even fewer parameters. FCViT-based models also demonstrate promising transferability to downstream tasks, like object detection, instance segmentation, and semantic segmentation. Codes and models are made available at: https://github.com/ma-xu/FCViT.

Astounding results from Transformer models on natural language tasks have intrigued the vision community to study their application to computer vision problems. Among their salient benefits, Transformers enable modeling long dependencies between input sequence elements and support parallel processing of sequence as compared to recurrent networks e.g., Long short-term memory (LSTM). Different from convolutional networks, Transformers require minimal inductive biases for their design and are naturally suited as set-functions. Furthermore, the straightforward design of Transformers allows processing multiple modalities (e.g., images, videos, text and speech) using similar processing blocks and demonstrates excellent scalability to very large capacity networks and huge datasets. These strengths have led to exciting progress on a number of vision tasks using Transformer networks. This survey aims to provide a comprehensive overview of the Transformer models in the computer vision discipline. We start with an introduction to fundamental concepts behind the success of Transformers i.e., self-attention, large-scale pre-training, and bidirectional feature encoding. We then cover extensive applications of transformers in vision including popular recognition tasks (e.g., image classification, object detection, action recognition, and segmentation), generative modeling, multi-modal tasks (e.g., visual-question answering, visual reasoning, and visual grounding), video processing (e.g., activity recognition, video forecasting), low-level vision (e.g., image super-resolution, image enhancement, and colorization) and 3D analysis (e.g., point cloud classification and segmentation). We compare the respective advantages and limitations of popular techniques both in terms of architectural design and their experimental value. Finally, we provide an analysis on open research directions and possible future works. We hope this effort will ignite further interest in the community to solve current challenges towards the application of transformer models in computer vision.

细粒度的图像识别是具有挑战性的，因为鉴别性线索通常是碎片化的，无论是来自单个图像还是多个图像。尽管有重要的改进，但大多数现有方法仍然专注于从单个图像中的最辨别部分，忽略其他地区的信息细节，缺乏从其他相关图像的线索考虑。在本文中，我们从新的角度分析了微粒图像识别的困难，并提出了一种具有峰值抑制模块和知识引导模块的变压器架构，其尊重单个图像中辨别特征的多样化和鉴别线索的聚合在多个图像中。具体地，峰值抑制模块首先利用线性投影来将输入图像转换为顺序令牌。然后，它基于变压器编码器产生的注意响应来阻止令牌。该模块因特征学习过程中的最辨别部分而受到惩罚，因此，提高了忽视区域的信息利用。知识引导模块将从峰值抑制模块生成的基于图像的表示与被学习的知识嵌入集进行比较，以获得知识响应系数。之后，使用响应系数作为分类分数，将知识学习形式形式化为分类问题。在训练期间更新知识嵌入和基于图像的表示，以便知识嵌入包括不同图像的鉴别线索。最后，我们将所获得的知识嵌入纳入基于形象的表示，作为全面的表示，导致性能显着提高。对六个流行数据集的广泛评估证明了所提出的方法的优势。

参考图像分割是典型的多模模式任务，其目的在于为给定语言表达式中描述的参考生成二进制掩码。现有技术采用双峰解决方案，以编码器 - 融合解码器管道内的两种方式采用图像和语言。但是，由于两个原因，该管道对目标任务进行了次优。首先，它们仅保险熔断由单模编码器产生的高级别功能，其妨碍了足够的跨模型学习。其次，UNI-Modal编码器是独立预先培训的，这在预训练的UNI-DOMAL任务和目标多模态任务之间带来不一致。此外，这种管道经常忽略或几乎没有使用直观有益的实例级别功能。为了减轻这些问题，我们提出了邮件，这是一个更简洁的编码器解码器管道，具有掩码图像语言Trimodal编码器。具体而言，邮件将Uni-Modal特征提取器及其融合模型统一到深度模态交互编码器中，促进了不同模式的足够的特征交互。同时，邮件直接避免了第二个限制，因为不再需要单模编码器。此外，我们第一次提出将实例掩码介绍为额外的模态，这明确加强了实例级别特征并促使更精细的分段结果。该邮件在所有常用的引用图像分割数据集中设置了一种新的最先进的，包括Refcoco，Refcoco +和G-Ref，具有显着的收益，与以前的最佳方法为3％-10％。代码即将发布。

Leveraging the advances of natural language processing, most recent scene text recognizers adopt an encoder-decoder architecture where text images are first converted to representative features and then a sequence of characters via `sequential decoding'. However, scene text images suffer from rich noises of different sources such as complex background and geometric distortions which often confuse the decoder and lead to incorrect alignment of visual features at noisy decoding time steps. This paper presents I2C2W, a novel scene text recognition technique that is tolerant to geometric and photometric degradation by decomposing scene text recognition into two inter-connected tasks. The first task focuses on image-to-character (I2C) mapping which detects a set of character candidates from images based on different alignments of visual features in an non-sequential way. The second task tackles character-to-word (C2W) mapping which recognizes scene text by decoding words from the detected character candidates. The direct learning from character semantics (instead of noisy image features) corrects falsely detected character candidates effectively which improves the final text recognition accuracy greatly. Extensive experiments over nine public datasets show that the proposed I2C2W outperforms the state-of-the-art by large margins for challenging scene text datasets with various curvature and perspective distortions. It also achieves very competitive recognition performance over multiple normal scene text datasets.

在现场文本识别中已经证明了语义信息。大多数现有方法倾向于将视觉和语义信息耦合到基于关注的解码器中。结果，语义特征的学习易于在训练集的有限词汇上具有偏差，这被称为词汇关系。在本文中，我们提出了一种新颖的视觉语义解耦网络（VSDN）来解决问题。我们的VSDN包含一个可视解码器（VD）和语义解码器（SD），以分别学习更纯度的视觉和语义特征表示。此外，语义编码器（SE）设计用于匹配SD，可以通过简单的单词校正任务通过额外的廉价大型词汇进行预先培训。因此，语义特征更加不偏并且精确地引导视觉特征对准并丰富最终字符表示。实验表明，我们的方法在标准基准上实现了最先进的或竞争力的结果，并且在培训集具有小尺寸的词汇量的情况下，在较大的余量下优于流行的基线。

最近，视觉变压器（VIT），具有自我关注（SA）作为事实上的成分，在计算机视觉社区中表现出很大的潜力。为了在效率和性能之间进行权衡，一组作品仅仅在本地补丁中执行SA操作，而全局上下文信息被放弃，这对于可视识别任务是不可或缺的。为了解决这个问题，随后的全球本地VITS在模型中以并行或替代方式将本地SA与全球范围内纳入本地SA。然而，令人遗憾地组合的局部和全局上下文可能存在各种视觉数据的冗余，并且每个层内的接收场是固定的。或者，更优雅的方式是全局和本地上下文可以自适应地贡献本身以适应不同的视觉数据。为实现这一目标，我们本文提出了一种新的Vit架构，称为NOMMER，可以动态提名视觉变压器中的协同全球本地背景。通过调查我们提出的NOMMER的工作模式，我们进一步探讨了哪些上下文信息。有益于这种“动态提名”机制，没有钟声和吹口哨，不仅可以在Imagenet上达到84.5％的前1个分类准确性，只有73米的参数，也显示了对致密预测任务的有希望的性能，即对象检测和语义分割。代码和模型将在〜\ url {https://github.com/nommer1125/nommer中公开可用。