盲目解构是一种在各种田地中产生的不良问题,从显微镜到天文学。问题的不良性质需要足够的前沿到达理想的解决方案。最近,已经表明,深度学习架构可以用作在无监督盲卷积优化期间的图像生成,然而甚至在单个图像上也呈现性能波动。我们建议使用Wiener-Deconvolulation在优化期间通过从高斯开始使用辅助内核估计来指导图像发生器在优化期间。我们观察到与低频特征相比,通过延迟再现去卷积的高频伪影。另外,图像发生器从模糊图像的速度再现解码图像的低频特征。我们在约束的优化框架中嵌入计算过程,并表明该方法在多个数据集中产生更高的稳定性和性能。此外,我们提供代码。
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监管基于深度学习的方法,产生医学图像分割的准确结果。但是,它们需要大量标记的数据集,并获得它们是一种艰苦的任务,需要临床专业知识。基于半/自我监督的学习方法通​​过利用未标记的数据以及有限的注释数据来解决此限制。最近的自我监督学习方法使用对比损失来从未标记的图像中学习良好的全球层面表示,并在像想象网那样的流行自然图像数据集上实现高性能。在诸如分段的像素级预测任务中,对于学习良好的本地级别表示以及全局表示来说至关重要,以实现更好的准确性。然而,现有的局部对比损失的方法的影响仍然是学习良好本地表现的限制,因为类似于随机增强和空间接近定义了类似和不同的局部区域;由于半/自我监督设置缺乏大规模专家注释,而不是基于当地地区的语义标签。在本文中,我们提出了局部对比损失,以便通过利用从未标记的图像的未标记图像的伪标签获得的语义标签信息来学习用于分割的良好像素级别特征。特别地,我们定义了建议的损失,以鼓励具有相同伪标签/标签的像素的类似表示,同时与数据集中的不同伪标签/标签的像素的表示。我们通过联合优化标记和未标记的集合和仅限于标记集的分割损失,通过联合优化拟议的对比损失来进行基于伪标签的自培训和培训网络。我们在三个公共心脏和前列腺数据集上进行了评估,并获得高分割性能。
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深度神经网络(DNN)对于对培训期间的样品大大减少的课程进行更多错误是臭名昭着的。这种类别不平衡在临床应用中普遍存在,并且对处理非常重要,因为样品较少的类通常对应于临界病例(例如,癌症),其中错误分类可能具有严重后果。不要错过这种情况,通过设定更高的阈值,需要以高真正的阳性率(TPRS)运行二进制分类器,但这是类别不平衡问题的非常高的假阳性率(FPRS)的成本。在课堂失衡下的现有方法通常不会考虑到这一点。我们认为,通过在高TPRS处于阳性的错误分类时强调减少FPRS,应提高预测准确性,即赋予阳性,即批判性,类样本与更高的成本相关。为此,我们将DNN的训练训练为二进制分类作为约束优化问题,并引入一种新的约束,可以通过在高TPR处优先考虑FPR减少来强制ROC曲线(AUC)下强制实施最大面积的新约束。我们使用增强拉格朗日方法(ALM)解决了由此产生的受限优化问题。超越二进制文件,我们还提出了两个可能的延长了多级分类问题的建议约束。我们使用内部医学成像数据集,CIFAR10和CIFAR100呈现基于图像的二元和多级分类应用的实验结果。我们的结果表明,该方法通过在关键类别的准确性上获得了大多数病例的拟议方法,同时降低了非关键类别样本的错误分类率。
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A key requirement for the success of supervised deep learning is a large labeled dataset -a condition that is difficult to meet in medical image analysis. Selfsupervised learning (SSL) can help in this regard by providing a strategy to pre-train a neural network with unlabeled data, followed by fine-tuning for a downstream task with limited annotations. Contrastive learning, a particular variant of SSL, is a powerful technique for learning image-level representations. In this work, we propose strategies for extending the contrastive learning framework for segmentation of volumetric medical images in the semi-supervised setting with limited annotations, by leveraging domain-specific and problem-specific cues. Specifically, we propose (1) novel contrasting strategies that leverage structural similarity across volumetric medical images (domain-specific cue) and (2) a local version of the contrastive loss to learn distinctive representations of local regions that are useful for per-pixel segmentation (problem-specific cue). We carry out an extensive evaluation on three Magnetic Resonance Imaging (MRI) datasets. In the limited annotation setting, the proposed method yields substantial improvements compared to other self-supervision and semi-supervised learning techniques. When combined with a simple data augmentation technique, the proposed method reaches within 8% of benchmark performance using only two labeled MRI volumes for training, corresponding to only 4% (for ACDC) of the training data used to train the benchmark. The code is made public at https://github.com/krishnabits001/domain_specific_cl. 34th Conference on Neural Information Processing Systems (NeurIPS 2020),
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We investigate algorithmic progress in image classification on ImageNet, perhaps the most well-known test bed for computer vision. We estimate a model, informed by work on neural scaling laws, and infer a decomposition of progress into the scaling of compute, data, and algorithms. Using Shapley values to attribute performance improvements, we find that algorithmic improvements have been roughly as important as the scaling of compute for progress computer vision. Our estimates indicate that algorithmic innovations mostly take the form of compute-augmenting algorithmic advances (which enable researchers to get better performance from less compute), not data-augmenting algorithmic advances. We find that compute-augmenting algorithmic advances are made at a pace more than twice as fast as the rate usually associated with Moore's law. In particular, we estimate that compute-augmenting innovations halve compute requirements every nine months (95\% confidence interval: 4 to 25 months).
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