Conference abstracts

Session B4 - Learning Theory

July 14, 17:00 ~ 17:25

Dictionary Learning: From Local to Global Convergence

Karin Schnass

University of Innsbruck, Austria   -   karin.schnass@uibk.ac.at

In this talk we first give conditions that guarantee one iteration of an alternating dictionary learning scheme to contract an estimate for the desired generating dictionary towards this generating dictionary. Conversely we will provide examples of dictionaries not equal to the generating dictionary that are stable fixed points of the alternating scheme. Based on these characterisations we then propose a (cheap) replacement strategy for alternate dictionary learning to avoid local minima. Time permitting we will finally discuss how the replacement strategy can be used to automatically determine the dictionary size and sparsity level.

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