Multilinear Low-Rank Tensors on Graphs & Applications

W e propose a new framework for the analysis of low-rank tensors which lies at the intersection of spectral graph theory and signal processing. As a first step, we present a new graph based low-rank decomposition which approximates the classical low-rank SVD for matrices and multi-linear SVD for tensors. Then, building on this novel decomposition we construct a general class of convex optimization problems for approximately solving low-rank tensor inverse problems, such as tensor Robust PCA. The whole framework is named as "Multilinear Low-rank tensors on Graphs (MLRTG)". Our theoretical analysis shows: 1) MLRTG stands on the notion of approximate stationarity of multidimensional signals on graphs and 2) the approximation error depends on the eigen gaps of the graphs. W e demonstrate applications for a wide variety of 4 artificial and 12 real tensor datasets, such as EEG, FMRI, BCI, surveillance videos and hyperspectral images. Generalization of the tensor concepts to non-euclidean domain, orders of magnitude speedup, low-memory requirement and significantly enhanced performance at low SNR are the key aspects of our framework.