Owing to the success of transformer models, recent works study their applicability in 3D medical segmentation tasks. Within the transformer models, the self-attention mechanism is one of the main building blocks that strives to capture long-range dependencies, compared to the local convolutional-based design. However, the self-attention operation has quadratic complexity which proves to be a computational bottleneck, especially in volumetric medical imaging, where the inputs are 3D with numerous slices. In this paper, we propose a 3D medical image segmentation approach, named UNETR++, that offers both high-quality segmentation masks as well as efficiency in terms of parameters and compute cost. The core of our design is the introduction of a novel efficient paired attention (EPA) block that efficiently learns spatial and channel-wise discriminative features using a pair of inter-dependent branches based on spatial and channel attention. Our spatial attention formulation is efficient having linear complexity with respect to the input sequence length. To enable communication between spatial and channel-focused branches, we share the weights of query and key mapping functions that provide a complimentary benefit (paired attention), while also reducing the overall network parameters. Our extensive evaluations on three benchmarks, Synapse, BTCV and ACDC, reveal the effectiveness of the proposed contributions in terms of both efficiency and accuracy. On Synapse dataset, our UNETR++ sets a new state-of-the-art with a Dice Similarity Score of 87.2%, while being significantly efficient with a reduction of over 71% in terms of both parameters and FLOPs, compared to the best existing method in the literature. Code: https://github.com/Amshaker/unetr_plus_plus.
translated by 谷歌翻译
Large-scale multi-modal training with image-text pairs imparts strong generalization to CLIP model. Since training on a similar scale for videos is infeasible, recent approaches focus on the effective transfer of image-based CLIP to the video domain. In this pursuit, new parametric modules are added to learn temporal information and inter-frame relationships which require meticulous design efforts. Furthermore, when the resulting models are learned on videos, they tend to overfit on the given task distribution and lack in generalization aspect. This begs the following question: How to effectively transfer image-level CLIP representations to videos? In this work, we show that a simple Video Fine-tuned CLIP (ViFi-CLIP) baseline is generally sufficient to bridge the domain gap from images to videos. Our qualitative analysis illustrates that the frame-level processing from CLIP image-encoder followed by feature pooling and similarity matching with corresponding text embeddings helps in implicitly modeling the temporal cues within ViFi-CLIP. Such fine-tuning helps the model to focus on scene dynamics, moving objects and inter-object relationships. For low-data regimes where full fine-tuning is not viable, we propose a `bridge and prompt' approach that first uses fine-tuning to bridge the domain gap and then learns prompts on language and vision side to adapt CLIP representations. We extensively evaluate this simple yet strong baseline on zero-shot, base-to-novel generalization, few-shot and fully supervised settings across five video benchmarks. Our code is available at https://github.com/muzairkhattak/ViFi-CLIP.
translated by 谷歌翻译
现有的开放式视频探测器通常通过利用不同形式的弱监督来扩大其词汇大小。这有助于推断出新的对象。开放式视频检测(OVD)中使用的两种流行形式的弱点,包括预审计的剪辑模型和图像级监督。我们注意到,这两种监督模式均未在检测任务中最佳地对齐:剪辑经过图像文本对培训,并且缺乏对象的精确定位,而图像级监督已与启发式方法一起使用,这些启发式方法无法准确指定本地对象区域。在这项工作中,我们建议通过从剪辑模型中执行以对象为中心的语言嵌入来解决此问题。此外,我们仅使用伪标记的过程来视觉上仅通过图像级监督对象,该过程提供高质量的对象建议,并有助于在训练过程中扩展词汇。我们通过新的重量转移函数在上述两个对象对准策略之间建立桥梁,该策略汇总了它们的免费强度。本质上,提出的模型试图最大程度地减少OVD设置中对象和以图像为中心表示之间的差距。在可可基准上,我们提出的方法在新颖类中实现了40.3 AP50,绝对11.9比以前的最佳性能获得了11.9的增长。对于LVIS,我们超过了5.0 Mask AP的最先进VILD模型,总体上有3.4个。 。代码:https://bit.ly/3byzoqp。
translated by 谷歌翻译
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。
translated by 谷歌翻译
什么构成一个物体?这是计算机愿景中的长期问题。为了实现这一目标,已经开发了许多基于学习的基于学习的方法来得分对象。但是,它们通常不会划过新域和未经看不见的对象。在本文中,我们倡导现有方法缺乏由人类可理解的语义管理的自上而下的监督信号。为了弥合这一差距,我们探索了已经用对齐的图像文本对培训的多模态视觉变压器(MVIT)。我们对各个域和新型对象的广泛实验显示了MVITS的最先进的性能,以使图像中的通用对象本地化。基于这些发现,我们使用多尺度特征处理和可变形的自我关注来开发一种高效且灵活的MVIT架构,可以自适应地生成给定特定语言查询的提议。我们展示了MVIT提案在各种应用中的重要性,包括开放世界对象检测,突出和伪装对象检测,监督和自我监督的检测任务。此外,MVITS提供了具有可理解文本查询的增强的交互性。代码:https://git.io/j1hpy。
translated by 谷歌翻译
Diabetic Retinopathy (DR) is considered one of the primary concerns due to its effect on vision loss among most people with diabetes globally. The severity of DR is mostly comprehended manually by ophthalmologists from fundus photography-based retina images. This paper deals with an automated understanding of the severity stages of DR. In the literature, researchers have focused on this automation using traditional machine learning-based algorithms and convolutional architectures. However, the past works hardly focused on essential parts of the retinal image to improve the model performance. In this paper, we adopt transformer-based learning models to capture the crucial features of retinal images to understand DR severity better. We work with ensembling image transformers, where we adopt four models, namely ViT (Vision Transformer), BEiT (Bidirectional Encoder representation for image Transformer), CaiT (Class-Attention in Image Transformers), and DeiT (Data efficient image Transformers), to infer the degree of DR severity from fundus photographs. For experiments, we used the publicly available APTOS-2019 blindness detection dataset, where the performances of the transformer-based models were quite encouraging.
translated by 谷歌翻译
This paper presents our solutions for the MediaEval 2022 task on DisasterMM. The task is composed of two subtasks, namely (i) Relevance Classification of Twitter Posts (RCTP), and (ii) Location Extraction from Twitter Texts (LETT). The RCTP subtask aims at differentiating flood-related and non-relevant social posts while LETT is a Named Entity Recognition (NER) task and aims at the extraction of location information from the text. For RCTP, we proposed four different solutions based on BERT, RoBERTa, Distil BERT, and ALBERT obtaining an F1-score of 0.7934, 0.7970, 0.7613, and 0.7924, respectively. For LETT, we used three models namely BERT, RoBERTa, and Distil BERTA obtaining an F1-score of 0.6256, 0.6744, and 0.6723, respectively.
translated by 谷歌翻译
Objective: Despite numerous studies proposed for audio restoration in the literature, most of them focus on an isolated restoration problem such as denoising or dereverberation, ignoring other artifacts. Moreover, assuming a noisy or reverberant environment with limited number of fixed signal-to-distortion ratio (SDR) levels is a common practice. However, real-world audio is often corrupted by a blend of artifacts such as reverberation, sensor noise, and background audio mixture with varying types, severities, and duration. In this study, we propose a novel approach for blind restoration of real-world audio signals by Operational Generative Adversarial Networks (Op-GANs) with temporal and spectral objective metrics to enhance the quality of restored audio signal regardless of the type and severity of each artifact corrupting it. Methods: 1D Operational-GANs are used with generative neuron model optimized for blind restoration of any corrupted audio signal. Results: The proposed approach has been evaluated extensively over the benchmark TIMIT-RAR (speech) and GTZAN-RAR (non-speech) datasets corrupted with a random blend of artifacts each with a random severity to mimic real-world audio signals. Average SDR improvements of over 7.2 dB and 4.9 dB are achieved, respectively, which are substantial when compared with the baseline methods. Significance: This is a pioneer study in blind audio restoration with the unique capability of direct (time-domain) restoration of real-world audio whilst achieving an unprecedented level of performance for a wide SDR range and artifact types. Conclusion: 1D Op-GANs can achieve robust and computationally effective real-world audio restoration with significantly improved performance. The source codes and the generated real-world audio datasets are shared publicly with the research community in a dedicated GitHub repository1.
translated by 谷歌翻译
Uncertainty quantification is crucial to inverse problems, as it could provide decision-makers with valuable information about the inversion results. For example, seismic inversion is a notoriously ill-posed inverse problem due to the band-limited and noisy nature of seismic data. It is therefore of paramount importance to quantify the uncertainties associated to the inversion process to ease the subsequent interpretation and decision making processes. Within this framework of reference, sampling from a target posterior provides a fundamental approach to quantifying the uncertainty in seismic inversion. However, selecting appropriate prior information in a probabilistic inversion is crucial, yet non-trivial, as it influences the ability of a sampling-based inference in providing geological realism in the posterior samples. To overcome such limitations, we present a regularized variational inference framework that performs posterior inference by implicitly regularizing the Kullback-Leibler divergence loss with a CNN-based denoiser by means of the Plug-and-Play methods. We call this new algorithm Plug-and-Play Stein Variational Gradient Descent (PnP-SVGD) and demonstrate its ability in producing high-resolution, trustworthy samples representative of the subsurface structures, which we argue could be used for post-inference tasks such as reservoir modelling and history matching. To validate the proposed method, numerical tests are performed on both synthetic and field post-stack seismic data.
translated by 谷歌翻译
In recent years distributional reinforcement learning has produced many state of the art results. Increasingly sample efficient Distributional algorithms for the discrete action domain have been developed over time that vary primarily in the way they parameterize their approximations of value distributions, and how they quantify the differences between those distributions. In this work we transfer three of the most well-known and successful of those algorithms (QR-DQN, IQN and FQF) to the continuous action domain by extending two powerful actor-critic algorithms (TD3 and SAC) with distributional critics. We investigate whether the relative performance of the methods for the discrete action space translates to the continuous case. To that end we compare them empirically on the pybullet implementations of a set of continuous control tasks. Our results indicate qualitative invariance regarding the number and placement of distributional atoms in the deterministic, continuous action setting.
translated by 谷歌翻译