Learning transformations for clustering and classification
Learning transformations for clustering and classification
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DOI：
10.5555/2789272.2789279
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发表时间：
2013-09
期刊：
影响因子：
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通讯作者：
Qiang Qiu;G. Sapiro
中科院分区：
文献类型：
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作者：
Qiang Qiu;G. Sapiro
提出了一种用于子空间聚类和分类的低秩变换学习框架。许多高维数据，如人脸图像和运动序列，近似地位于低维子空间的并集中。相应的子空间聚类问题已经在文献中得到了广泛的研究，以将这些高维数据划分为与其底层低维子空间相对应的聚类。然而，低维的内在结构经常被现实世界的观测所破坏，因为它们可能被错误破坏或偏离理想模型。我们建议通过学习子空间上的线性变换，使用矩阵秩，通过其凸代理核范数，作为优化标准来解决这个问题。学习的线性变换恢复来自相同子空间的数据的低秩结构，并且同时强制来自不同子空间的数据的最大分离结构。通过这种方式，我们减少了子空间内的变化，并增加了子空间之间的分离，以实现更鲁棒的子空间聚类。该学习鲁棒子空间聚类框架显著提高了现有子空间聚类方法的性能。这里提出的基本理论结果有助于进一步支持基本框架。为了利用变换后的子空间的低秩结构，我们进一步引入了一种快速子空间聚类技术，该技术有效地结合了鲁棒PCA和稀疏建模。当类标签出现在训练阶段时，我们发现这种低秩变换框架也显著提高了分类性能。使用公共数据集进行的大量实验表明，该方法显着优于最先进的子空间聚类和分类方法。
A low-rank transformation learning framework for subspace clustering and classification is here proposed. Many high-dimensional data, such as face images and motion sequences, approximately lie in a union of low-dimensional subspaces. The corresponding subspace clustering problem has been extensively studied in the literature to partition such high-dimensional data into clusters corresponding to their underlying low-dimensional subspaces. However, low-dimensional intrinsic structures are often violated for real-world observations, as they can be corrupted by errors or deviate from ideal models. We propose to address this by learning a linear transformation on subspaces using matrix rank, via its convex surrogate nuclear norm, as the optimization criteria. The learned linear transformation restores a low-rank structure for data from the same subspace, and, at the same time, forces a a maximally separated structure for data from different subspaces. In this way, we reduce variations within subspaces, and increase separation between subspaces for a more robust subspace clustering. This proposed learned robust subspace clustering framework significantly enhances the performance of existing subspace clustering methods. Basic theoretical results here presented help to further support the underlying framework. To exploit the low-rank structures of the transformed subspaces, we further introduce a fast subspace clustering technique, which efficiently combines robust PCA with sparse modeling. When class labels are present at the training stage, we show this low-rank transformation framework also significantly enhances classification performance. Extensive experiments using public datasets are presented, showing that the proposed approach significantly outperforms state-of-the-art methods for subspace clustering and classification.