2022/04/18 by Jarek Duda, Duda, Jarek · 1 citation
Computer Science · Engineering · #Matrix Theory and Algorithms #Blind Source Separation Techniques #Sparse and Compressive Sensing Techniques
paper · pdf · doi:10.48550/arxiv.2204.08242
SVD (singular value decomposition) is one of the basic tools of machine learning, allowing to optimize basis for a given matrix. However, sometimes we have a set of matrices \Ak\k instead, and would like to optimize a single common basis for them: find orthogonal matrices U, V, such that \UT Ak V\ set of matrices is somehow simpler. For example DCT-II is orthonormal basis of functions commonly used in image/video compression - as discussed here, this kind of basis can be quickly automatically optimized for a given dataset. While also discussed gradient descent optimization might be computationally costly, there is proposed CSVD (common SVD): fast general approach based on SVD. Specifically, we choose U as built of eigenvectors of ∑i (wk)q (Ak AkT)p and V of ∑k (wk)q (AkT Ak)p, where wk are their weights, p,q>0 are some chosen powers e.g. 1/2, optionally with normalization e.g. A → A - rcT where ri=∑j Aij, cj =∑i Aij.