# The bridge from orthogonal to redundant transforms and weighted $\ell_1$ optimization

 Title The bridge from orthogonal to redundant transforms and weighted $\ell_1$ optimization Publication Type SINBAD Presentation Authors Brock Hargreaves, Ozgur Yilmaz, Felix J. Herrmann Publisher SINBAD Year of Publication 2013 Abstract Traditional arguments in synthesis $\ell_1$ -optimization require our forward operator to be orthogonal, though we use redundant transforms in practice. These traditional arguments do not translate to redundant transforms, and other arguments require impractical conditions on our effective measurement matrix. Recent theory in one-norm analysis, namely the optimal dual $\ell_1$ analysis of Shidong et al, have provided point-wise reconstruction error estimates for synthesis using an equivalence relationship where we can use weaker assumptions. This exposes an important model assumption indicating why analysis might outperform synthesis, for which careful consideration in seismic is necessary, and the need for models such as the cosparse model. In this talk we will discuss these ideas, provide evidence which indicates this theory should generalize to uniform error estimates(and thus not signal dependent), and how redundancy, support information, and weighting play important roles. Keywords Presentation, private, SINBAD, SINBADFALL2013, SLIM URL https://www.slim.eos.ubc.ca/Publications/Private/Conferences/SINBAD/2013/Fall/hargreaves2013SINBADbfo/hargreaves2013SINBADbfo.pdf Citation Key hargreaves2013SINBADbfo