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arXiv 2203.07307cs.CVstat.ML
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S5CL:通过分层对比学习统一全监督、自监督和半监督学习

S5CL: Unifying Fully-Supervised, Self-Supervised, and Semi-Supervised Learning Through Hierarchical Contrastive Learning

Technical University Munich(慕尼黑工业大学);Helmholtz AI(亥姆霍兹人工智能研究院)

Manuel Tran, Sophia J. Wagner, Melanie Boxberg, Tingying Peng

摘要:

在计算病理学中,我们经常面临着缺乏注释和大量未标记数据的问题。处理这种情况的一种方法是半监督学习,它通常分为自我监督的借口任务和随后的模型微调。在这里,我们通过引入S5 CL将这两个阶段的训练压缩为一个,S5 CL是一个用于全监督、自监督和半监督学习的统一框架。通过为标记图像、未标记图像和伪标记图像定义三种对比度损失,S5 CL可以学习反映距离关系层次的特征表示:相似图像和增强嵌入最接近,其次是同一类的不同外观图像,而来自不同类的图像具有最大的距离。此外,S5 CL允许我们灵活地组合这些损失,以适应不同的场景。在两个公共组织病理学数据集上对我们的框架进行的评估显示,在稀疏标签的情况下,我们的框架有了很大的改进:对于H& E染色的结直肠癌数据集,与监督交叉熵损失相比,准确度提高了9%;对于来自白血病患者血涂片的单个白细胞的高度不平衡数据集,F1分数提高了6%。

英文摘要:

In computational pathology, we often face a scarcity of annotations and a large amount of unlabeled data. One method for dealing with this is semi-supervised learning which is commonly split into a self-supervised pretext task and a subsequent model fine-tuning. Here, we compress this two-stage training into one by introducing S5CL, a unified framework for fully-supervised, self-supervised, and semi-supervised learning. With three contrastive losses defined for labeled, unlabeled, and pseudo-labeled images, S5CL can learn feature representations that reflect the hierarchy of distance relationships: similar images and augmentations are embedded the closest, followed by different looking images of the same class, while images from separate classes have the largest distance. Moreover, S5CL allows us to flexibly combine these losses to adapt to different scenarios. Evaluations of our framework on two public histopathological datasets show strong improvements in the case of sparse labels: for a H&E-stained colorectal cancer dataset, the accuracy increases by up to 9% compared to supervised cross-entropy loss; for a highly imbalanced dataset of single white blood cells from leukemia patient blood smears, the F1-score increases by up to 6%.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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