×

On \(\ell_1\) data fitting and concave regularization for image recovery. (English) Zbl 1267.65028

The authors propose a new family of cost functions for signal and image recovery: they are composed of \(\ell_1\) data fitting terms combined with concave regularization. They exhibit when and how to employ such cost functions. Their theoretical results show that the minimizers of these cost functions are such that each one of their entries is involved either in an exact data fitting component or in a null component of the regularization part. This is a strong and particular property that can be useful for various image recovery problems. The minimization of such cost functions presents a computational challenge. Also they propose a fast minimization algorithm to solve this numerical problem. The experimental results show the effectiveness of the proposed algorithm. All illustrations and numerical experiments give a flavor of the possibilities offered by the minimizers of this new family of cost functions in solving specialized image processing tasks.

MSC:

65D18 Numerical aspects of computer graphics, image analysis, and computational geometry
65F22 Ill-posedness and regularization problems in numerical linear algebra
65K05 Numerical mathematical programming methods
90C26 Nonconvex programming, global optimization
90C53 Methods of quasi-Newton type
94A05 Communication theory
94A12 Signal theory (characterization, reconstruction, filtering, etc.)
65D10 Numerical smoothing, curve fitting
Full Text: DOI