Parametric dictionary design for sparse coding

  • Authors:
  • Mehrdad Yaghoobi;Laurent Daudet;Mike E. Davies

  • Affiliations:
  • Institute for Digital Communication and with the Joint Research Institute for Signal and Image Processing, Edinburgh University, Edinburgh, U.K.;Université Paris Diderot-Paris 7, Institut Langevin "waves and image", LOA, UMR, Paris Cedex 05, France and Pierre-and-Marie-Curie University-Paris 6, Paris, France;Institute for Digital Communication and with the Joint Research Institute for Signal and Image Processing, Edinburgh University, Edinburgh, U.K.

  • Venue:
  • IEEE Transactions on Signal Processing
  • Year:
  • 2009

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Abstract

This paper introduces a new dictionary design method for sparse coding of a class of signals. It has been shown that one can sparsely approximate some natural signals using an overcomplete set of parametric functions. A problem in using these parametric dictionaries is how to choose the parameters. In practice, these parameters have been chosen by an expert or through a set of experiments. In the sparse approximation context, it has been shown that an incoherent dictionary is appropriate for the sparse approximation methods. In this paper, we first characterize the dictionary design problem, subject to a constraint on the dictionary. Then we briefly explain that equiangular tight frames have minimum coherence. The complexity of the problem does not allow it to be solved exactly. We introduce a practical method to approximately solve it. Some experiments show the advantages one gets by using these dictionaries.