Quantifying the perceptual similarity of two images is a long-standing problem in low-level computer vision. The natural image domain commonly relies on supervised learning, e.g., a pre-trained VGG, to obtain a latent representation. However, due to domain shift, pre-trained models from the natural image domain might not apply to other image domains, such as medical imaging. Notably, in medical imaging, evaluating the perceptual similarity is exclusively performed by specialists trained extensively in diverse medical fields. Thus, medical imaging remains devoid of task-specific, objective perceptual measures. This work answers the question: Is it necessary to rely on supervised learning to obtain an effective representation that could measure perceptual similarity, or is self-supervision sufficient? To understand whether recent contrastive self-supervised representation (CSR) may come to the rescue, we start with natural images and systematically evaluate CSR as a metric across numerous contemporary architectures and tasks and compare them with existing methods. We find that in the natural image domain, CSR behaves on par with the supervised one on several perceptual tests as a metric, and in the medical domain, CSR better quantifies perceptual similarity concerning the experts' ratings. We also demonstrate that CSR can significantly improve image quality in two image synthesis tasks. Finally, our extensive results suggest that perceptuality is an emergent property of CSR, which can be adapted to many image domains without requiring annotations.
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在几乎不可预测且通常严重的主题运动的情况下获得的多个MR Slices的胎儿大脑的体积重建是一项具有挑战性的任务,对切片转换的初始化非常敏感。我们建议使用经过合成转换数据训练的变压器提出了一种新型的切片到体积的注册方法,该数据将MR Slices的多个堆栈模拟为序列。通过注意机制,我们的模型会自动检测切片之间的相关性,并使用来自其他切片的信息预测一个切片的转换。我们还估计了基础3D卷,以帮助切片到体积的注册,并交替更新音量和转换以提高准确性。合成数据的结果表明,与现有的最新方法相比,我们的方法可实现较低的注册误差和更好的重建质量。还进行了使用现实世界中MRI数据的实验,以证明该模型在严重的胎儿运动下提高3D重建质量的能力。
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尽管数据增强和转移学习有所进步,但卷积神经网络(CNNS)难以推广到看不见的域。在分割大脑扫描时,CNN对分辨率和对比度的变化非常敏感:即使在相同的MRI模式内,则性能可能会跨数据集减少。在这里,我们介绍了Synthseg,第一个分段CNN无关紧要对比和分辨率。 Synthseg培训,用从分段上的生成模型采样的合成数据培训。至关重要,我们采用域随机化策略,我们完全随机开启了合成培训数据的对比度和解决。因此,Synthseg可以在没有再培训或微调的情况下对任何目标结构域进行真实扫描,这是首次分析大量的异构临床数据。因为Synthseg仅需要进行培训(无图像),所以它可以从通过不同群体的对象(例如,老化和患病)的自动化方法获得的标签中学习,从而实现广泛的形态变异性的鲁棒性。我们展示了Synthseg在六种方式的5,300扫描和十项决议中,与监督CNN,最先进的域适应和贝叶斯分割相比,它表现出无与伦比的泛化。最后,我们通过将其施加到心脏MRI和CT分割来证明SyntheeG的恒定性。
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我们提出了明确结合频率和图像特征表示的神经网络层,并表明它们可以用作频率空间数据重建的多功能构建块。我们的工作是由MRI习得引起的挑战所激发的,该挑战是信号是所需图像的傅立叶变换。提出的联合学习方案既可以校正频率空间的天然伪像,又可以操纵图像空间表示,以重建网络各层的相干图像结构。这与图像重建的大多数当前深度学习方法形成鲜明对比,该方法分别处理频率和图像空间特征,并且通常在两个空间之一中仅运行。我们证明了联合卷积学习在各种任务中的优势,包括运动校正,denosing,从不足采样的采集中重建,以及对模拟和现实世界多层MRI数据的混合采样和运动校正。联合模型在所有任务和数据集中都始终如一地产生高质量的输出图像。当整合到具有物理启发的数据一致性约束的最终采样重建的情况下,将其集成到艺术风化的优化网络中时,提议的体系结构显着改善了优化景观,从而产生了减少训练时间的数量级。该结果表明,联合表示特别适合深度学习网络中的MRI信号。我们的代码和预算模型可在https://github.com/nalinimsingh/interlacer上公开获得。
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每年都会在医院中获得数百万个大脑MRI扫描,这比任何研究数据集的规模都要大得多。因此,分析此类扫描的能力可以改变神经成像研究。然而,由于没有自动化算法可以应对临床采集的高度可变性(MR对比度,分辨率,方向等),因此它们的潜力仍未开发。在这里,我们提出了Synthseg+,这是一个AI分割套件,首次可以对异质临床数据集进行强有力的分析。具体而言,除了全脑分割外,SynthSeg+还执行皮质细胞,颅内体积估计和自动检测故障分割(主要是由质量非常低的扫描引起的)。我们在七个实验中证明了合成++,包括对14,000张扫描的老化研究,在该研究中,它准确地复制了在质量更高的数据上观察到的萎缩模式。 Synthseg+公开发布是一种现成的工具,可在广泛设置中解锁定量形态计量学的潜力。
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There is a dramatic shortage of skilled labor for modern vineyards. The Vinum project is developing a mobile robotic solution to autonomously navigate through vineyards for winter grapevine pruning. This necessitates an autonomous navigation stack for the robot pruning a vineyard. The Vinum project is using the quadruped robot HyQReal. This paper introduces an architecture for a quadruped robot to autonomously move through a vineyard by identifying and approaching grapevines for pruning. The higher level control is a state machine switching between searching for destination positions, autonomously navigating towards those locations, and stopping for the robot to complete a task. The destination points are determined by identifying grapevine trunks using instance segmentation from a Mask Region-Based Convolutional Neural Network (Mask-RCNN). These detections are sent through a filter to avoid redundancy and remove noisy detections. The combination of these features is the basis for the proposed architecture.
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Ithaca is a Fuzzy Logic (FL) plugin for developing artificial intelligence systems within the Unity game engine. Its goal is to provide an intuitive and natural way to build advanced artificial intelligence systems, making the implementation of such a system faster and more affordable. The software is made up by a C\# framework and an Application Programming Interface (API) for writing inference systems, as well as a set of tools for graphic development and debugging. Additionally, a Fuzzy Control Language (FCL) parser is provided in order to import systems previously defined using this standard.
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Quantum Machine Learning (QML) shows how it maintains certain significant advantages over machine learning methods. It now shows that hybrid quantum methods have great scope for deployment and optimisation, and hold promise for future industries. As a weakness, quantum computing does not have enough qubits to justify its potential. This topic of study gives us encouraging results in the improvement of quantum coding, being the data preprocessing an important point in this research we employ two dimensionality reduction techniques LDA and PCA applying them in a hybrid way Quantum Support Vector Classifier (QSVC) and Variational Quantum Classifier (VQC) in the classification of Diabetes.
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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.
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Understanding 3D environments semantically is pivotal in autonomous driving applications where multiple computer vision tasks are involved. Multi-task models provide different types of outputs for a given scene, yielding a more holistic representation while keeping the computational cost low. We propose a multi-task model for panoptic segmentation and depth completion using RGB images and sparse depth maps. Our model successfully predicts fully dense depth maps and performs semantic segmentation, instance segmentation, and panoptic segmentation for every input frame. Extensive experiments were done on the Virtual KITTI 2 dataset and we demonstrate that our model solves multiple tasks, without a significant increase in computational cost, while keeping high accuracy performance. Code is available at https://github.com/juanb09111/PanDepth.git
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