2019 - T1 - WS1 - Variational methods and optimization in imaging

Collection 2019 - T1 - WS1 - Variational methods and optimization in imaging

Organizer(s)
Date(s) 04/02/2019 - 08/02/2019
00:00:00 / 00:00:00
10 22

On support localisation, the Fisher metric and optimal sampling in off-the-grid sparse regularisation

By Clarice Poon

Sparse regularization is a central technique for both machine learning and imaging sciences. Existing performance guarantees assume a separation of the spikes based on an ad-hoc (usually Euclidean) minimum distance condition, which ignore the geometry of the problem. In this talk, we study the BLASSO (i.e. the off-the-grid version of ℓ1 LASSO regularization) and show that the Fisher-Rao distance is the natural way to ensure and quantify support recovery. Under a separation imposed by this distance, I will present results which show that stable recovery of a sparse measure can be achieved when the sampling complexity is (up to log factors) linear with sparsity. On deconvolution problems, which are translation invariant, this generalizes to the multi-dimensional setting existing results of the literature. For more complex translation-varying problems, such as Laplace transform inversion, this gives the first geometry-aware guarantees for sparse recovery. This is joint work with Nicolas Keriven and Gabriel Peyré.

Information about the video

Last related questions on MathOverflow

You have to connect your Carmin.tv account with mathoverflow to add question

Ask a question on MathOverflow




Register

  • Bookmark videos
  • Add videos to see later &
    keep your browsing history
  • Comment with the scientific
    community
  • Get notification updates
    for your favorite subjects
Give feedback