Poddar Sunrita, Jacob Mathews
Department of Electrical and Computer Engineering, University of Iowa, IA, USA.
Proc IEEE Int Conf Acoust Speech Signal Process. 2018 Apr;2018:4024-4028. doi: 10.1109/icassp.2018.8462186. Epub 2018 Sep 13.
We introduce a continuous domain framework for the recovery of points on a surface in high dimensional space, represented as the zero-level set of a bandlimited function. We show that the exponential maps of the points on the surface satisfy annihilation relations, implying that they lie in a finite dimensional subspace. The subspace properties are used to derive sampling conditions, which will guarantee the perfect recovery of the surface from finite number of points. We rely on nuclear norm minimization to exploit the low-rank structure of the maps to recover the points from noisy measurements. Since the direct estimation of the surface is computationally prohibitive in very high dimensions, we propose an iterative reweighted algorithm using the "kernel trick". The iterative algorithm reveals deep links to Laplacian based algorithms widely used in graph signal processing; the theory and the sampling conditions can serve as a basis for discrete-continuous domain processing of signals on a graph.
我们引入了一个连续域框架,用于恢复高维空间中曲面上的点,这些点被表示为一个带限函数的零水平集。我们证明了曲面上点的指数映射满足湮灭关系,这意味着它们位于一个有限维子空间中。利用子空间性质推导出采样条件,该条件将保证从有限数量的点中完美恢复曲面。我们依靠核范数最小化来利用映射的低秩结构,以便从有噪声的测量中恢复点。由于在非常高的维度下直接估计曲面在计算上是不可行的,我们提出了一种使用“核技巧”的迭代重加权算法。该迭代算法揭示了与广泛应用于图信号处理的基于拉普拉斯的算法的深层联系;该理论和采样条件可作为图上信号离散 - 连续域处理的基础。