Robert Nowak

Sparse Reconstruction by Separable Approximation

  • Mario A. T. Figueiredo
  • Stephen Wright
  • Robert Nowak
    • Categories Applications - Science and Engineering, Convex and Nonsmooth Optimization Tags , , ,

    Finding sparse approximate solutions to large underdetermined linear systems of equations is a common problem in signal/image processing and statistics. Basis pursuit, the least absolute shrinkage and selection operator (LASSO), wavelet-based deconvolution and reconstruction, and compressed sensing (CS) are a few well-known areas in which problems of this type appear. One standard approach is to … Read more

    Gradient Projection for Sparse Reconstruction: Application to Compressed Sensing and Other Inverse Problems

  • Mario A. T. Figueiredo
  • Stephen Wright
  • Robert Nowak
    • Categories Applications - Science and Engineering, Bound-constrained Optimization Tags ,

    Many problems in signal processing and statistical inference involve finding sparse solutions to under-determined, or ill-conditioned, linear systems of equations. A standard approach consists in minimizing an objective function which includes a quadratic (squared $\ell_2$) error term combined with a sparseness-inducing ($\ell_1$) regularization term.{\it Basis pursuit}, the {\it least absolute shrinkage and selection operator} (LASSO), … Read more