arXivDaily arXiv每日学术速递 周一至周五更新
arXiv 1209.3079stat.MLmath.OC
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子空间并中的信号恢复及其在压缩成像中的应用

Signal Recovery in Unions of Subspaces with Applications to Compressive Imaging

Nikhil Rao, Benjamin Recht, Robert Nowak

摘要:

在从通信到遗传学的应用中,信号可以被建模为位于子空间的并集中。在该模型下,位于某些子空间中的信号系数一起是活动的或不活动的。潜在的子空间是预先已知的,但是活动的子空间的特定集合(即,在信号支持中)必须从测量中学习。我们表明,利用知识的子空间可以进一步减少精确的信号恢复所需的测量数量,并推导出所需的测量数量的普遍界限。这个界是普适的,因为它只取决于所考虑的子空间的数量,以及它们之间的相对方向。子空间的细节(例如,组成、尺寸、范围、重叠等)并不影响我们获得的结果。在这个过程中,我们推导出样本复杂性界限的特殊情况下的组套索重叠组(潜在组套索),这是在各种应用程序中使用。最后,我们还表明,图像的小波变换系数可以建模为躺在组,因此可以有效地恢复使用组套索方法。

英文摘要:

In applications ranging from communications to genetics, signals can be modeled as lying in a union of subspaces. Under this model, signal coefficients that lie in certain subspaces are active or inactive together. The potential subspaces are known in advance, but the particular set of subspaces that are active (i.e., in the signal support) must be learned from measurements. We show that exploiting knowledge of subspaces can further reduce the number of measurements required for exact signal recovery, and derive universal bounds for the number of measurements needed. The bound is universal in the sense that it only depends on the number of subspaces under consideration, and their orientation relative to each other. The particulars of the subspaces (e.g., compositions, dimensions, extents, overlaps, etc.) does not affect the results we obtain. In the process, we derive sample complexity bounds for the special case of the group lasso with overlapping groups (the latent group lasso), which is used in a variety of applications. Finally, we also show that wavelet transform coefficients of images can be modeled as lying in groups, and hence can be efficiently recovered using group lasso methods.

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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