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.
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Recent efforts in Neural Rendering Fields (NeRF) have shown impressive results on novel view synthesis by utilizing implicit neural representation to represent 3D scenes. Due to the process of volumetric rendering, the inference speed for NeRF is extremely slow, limiting the application scenarios of utilizing NeRF on resource-constrained hardware, such as mobile devices. Many works have been conducted to reduce the latency of running NeRF models. However, most of them still require high-end GPU for acceleration or extra storage memory, which is all unavailable on mobile devices. Another emerging direction utilizes the neural light field (NeLF) for speedup, as only one forward pass is performed on a ray to predict the pixel color. Nevertheless, to reach a similar rendering quality as NeRF, the network in NeLF is designed with intensive computation, which is not mobile-friendly. In this work, we propose an efficient network that runs in real-time on mobile devices for neural rendering. We follow the setting of NeLF to train our network. Unlike existing works, we introduce a novel network architecture that runs efficiently on mobile devices with low latency and small size, i.e., saving $15\times \sim 24\times$ storage compared with MobileNeRF. Our model achieves high-resolution generation while maintaining real-time inference for both synthetic and real-world scenes on mobile devices, e.g., $18.04$ms (iPhone 13) for rendering one $1008\times756$ image of real 3D scenes. Additionally, we achieve similar image quality as NeRF and better quality than MobileNeRF (PSNR $26.15$ vs. $25.91$ on the real-world forward-facing dataset).
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Nerf-based Generative models have shown impressive capacity in generating high-quality images with consistent 3D geometry. Despite successful synthesis of fake identity images randomly sampled from latent space, adopting these models for generating face images of real subjects is still a challenging task due to its so-called inversion issue. In this paper, we propose a universal method to surgically fine-tune these NeRF-GAN models in order to achieve high-fidelity animation of real subjects only by a single image. Given the optimized latent code for an out-of-domain real image, we employ 2D loss functions on the rendered image to reduce the identity gap. Furthermore, our method leverages explicit and implicit 3D regularizations using the in-domain neighborhood samples around the optimized latent code to remove geometrical and visual artifacts. Our experiments confirm the effectiveness of our method in realistic, high-fidelity, and 3D consistent animation of real faces on multiple NeRF-GAN models across different datasets.
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Artificial Intelligence (AI) is having a tremendous impact across most areas of science. Applications of AI in healthcare have the potential to improve our ability to detect, diagnose, prognose, and intervene on human disease. For AI models to be used clinically, they need to be made safe, reproducible and robust, and the underlying software framework must be aware of the particularities (e.g. geometry, physiology, physics) of medical data being processed. This work introduces MONAI, a freely available, community-supported, and consortium-led PyTorch-based framework for deep learning in healthcare. MONAI extends PyTorch to support medical data, with a particular focus on imaging, and provide purpose-specific AI model architectures, transformations and utilities that streamline the development and deployment of medical AI models. MONAI follows best practices for software-development, providing an easy-to-use, robust, well-documented, and well-tested software framework. MONAI preserves the simple, additive, and compositional approach of its underlying PyTorch libraries. MONAI is being used by and receiving contributions from research, clinical and industrial teams from around the world, who are pursuing applications spanning nearly every aspect of healthcare.
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最近的几项著作从经验上发现,鉴定学习率对于神经网络结构修剪的最终表现至关重要。进一步的研究发现,网络训练性通过修剪答案而破坏,因此呼吁迫切需要在填充之前恢复训练性。现有的尝试建议利用重量正交化以实现动态等轴测图,以提高训练性。但是,它们仅适用于线性MLP网络。如何开发一种维护或恢复可训练性并且可扩展到现代深网的过滤器修剪方法仍然难以捉摸。在本文中,我们提出了维护修剪(TPP)的训练性,这是一种基于正则化的结构化修剪方法,可以有效地维持稀疏期间的训练性。具体而言,TPP将卷积内核的革兰氏矩阵正规化,以从保存的过滤器中解除修剪过滤器。除了卷积层外,我们还建议将BN参数正规化,以更好地保留训练性。从经验上讲,TPP可以与线性MLP网络上的基地真相动力学恢复方法竞争。在非线性网络(RESNET56/VGG19,CIFAR数据集)上,它的表现优于其他对应解决方案。此外,与许多表现最好的滤镜修剪方法相比,TPP还可以在ImageNet上与现代深层网络(RESENET)有效地工作,从而提供了令人鼓舞的性能。据我们所知,这是第一种在大规模深度神经网络修剪过程中有效维持训练性的第一种方法。
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图像栅格化是计算机图形中的一种成熟技术,而图像矢量化(栅格化的反向路径)仍然是一个重大挑战。最近的先进的基于深度学习的模型实现了向量图的矢量化和语义插值,并证明了生成新数字的更好拓扑。但是,深层模型不能轻易推广到室外测试数据。生成的SVG还包含复杂而冗余的形状,这些形状并不是进一步编辑的方便。具体而言,图像中关键的层拓扑和基本语义仍然没有很好地理解,因此尚未完全探索。在这项工作中,我们提出了层次图像矢量化,即现场,以将栅格图像转换为SVG并同时维护其图像拓扑。 Live可以产生紧凑的SVG形式,具有与人类视角一致的层结构。我们逐步添加新的bezier路径,并通过层面框架,新设计的损耗功能和组件途径初始化技术优化这些路径。我们的实验表明,与先前的作品相比,Live呈现出更合理的矢量形式,并且可以推广到新图像。在这个新知识的拓扑结构的帮助下,Live为设计师和其他下游应用程序启动了人类可编辑的SVG。代码可在https://github.com/picsart-ai-research/live-layerwise-image-vectorization上找到。
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关于神经辐射场(NERF)的最新研究爆炸表明,具有神经网络的复杂场面具有令人鼓舞的潜力。 NERF的一个主要缺点是它的推理时间:渲染单像素需要数百次查询NERF网络。为了解决它,现有的努力主要试图减少所需的采样点的数量。但是,迭代采样的问题仍然存在。另一方面,神经光场(NELF)在新型视图合成中对NERF提出了更直接的表示 - 像素的渲染相当于一个单一的正向通行,而无需射线建设。在这项工作中,我们提出了一个深层残留的MLP网络(88层),以有效地学习光场。我们展示了成功学习这种深度NELF网络的关键,就是拥有足够的数据,我们通过数据蒸馏从预训练的NERF模型中转移知识。在合成和现实世界场景上进行的广泛实验表明,我们方法比其他对应算法的优点。在合成场景中,我们实现了26-35倍的拖鞋(每个摄像头射线)和28-31倍的运行时加速,同时提供了比NERF的呈现质量(1.4-2.8 dB的平均PSNR改善),而无需任何定制的并行性要求。
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从纯图像和具有对比性损失的纯图像和文本预测的自我监督的视觉语言是有效的,但是由于双流式体系结构仅在全球层面上与图像和文本表示形式对齐,因此忽略了细粒度​​的对齐。早些时候,受监督的,非对比度的方法具有更细粒度的对齐方式,但需要致密的注释,这些注释不可伸缩。我们提出了一个单个流体系结构,该体系结构使用两个新颖的任务:对称交叉模式重建(XMM)和一个伪标记的关键字预测,将图像和语言对齐:全局,细粒度的补丁和概念/语义(PSL)。在XMM中,我们从一种模态掩盖了输入令牌,并使用跨模式信息重建掩盖的令牌,从而改善了两种模式之间的细粒度对齐。在PSL中,我们使用注意力在标题中选择关键字,使用动量编码器推荐标题中缺少但在图像中表示的其他重要关键字,然后训练视觉编码器以预测这些关键字的存在,并帮助它。学习对于将文本令牌接地到图像区域至关重要的语义概念。我们证明了对图像文本检索,接地,视觉问题的回答/推理的竞争性能和提高的数据效率,以针对对更多数据进行培训的较大模型和模型。 Zaidkhan.me/simla上可用的代码和型号。
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Convolutional neural network (CNN) has achieved great success on image super-resolution (SR). However, most deep CNN-based SR models take massive computations to obtain high performance. Downsampling features for multi-resolution fusion is an efficient and effective way to improve the performance of visual recognition. Still, it is counter-intuitive in the SR task, which needs to project a low-resolution input to high-resolution. In this paper, we propose a novel Hybrid Pixel-Unshuffled Network (HPUN) by introducing an efficient and effective downsampling module into the SR task. The network contains pixel-unshuffled downsampling and Self-Residual Depthwise Separable Convolutions. Specifically, we utilize pixel-unshuffle operation to downsample the input features and use grouped convolution to reduce the channels. Besides, we enhance the depthwise convolution's performance by adding the input feature to its output. Experiments on benchmark datasets show that our HPUN achieves and surpasses the state-of-the-art reconstruction performance with fewer parameters and computation costs.
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Point cloud analysis is challenging due to irregularity and unordered data structure. To capture the 3D geometries, prior works mainly rely on exploring sophisticated local geometric extractors using convolution, graph, or attention mechanisms. These methods, however, incur unfavorable latency during inference, and the performance saturates over the past few years. In this paper, we present a novel perspective on this task. We notice that detailed local geometrical information probably is not the key to point cloud analysis -- we introduce a pure residual MLP network, called PointMLP, which integrates no sophisticated local geometrical extractors but still performs very competitively. Equipped with a proposed lightweight geometric affine module, PointMLP delivers the new state-of-the-art on multiple datasets. On the real-world ScanObjectNN dataset, our method even surpasses the prior best method by 3.3% accuracy. We emphasize that PointMLP achieves this strong performance without any sophisticated operations, hence leading to a superior inference speed. Compared to most recent CurveNet, PointMLP trains 2x faster, tests 7x faster, and is more accurate on ModelNet40 benchmark. We hope our PointMLP may help the community towards a better understanding of point cloud analysis. The code is available at https://github.com/ma-xu/pointMLP-pytorch.
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