A Fast Iterative Shrinkage-Thresholding Algorithm for Linear Inverse Problems

Authors

Amir Beck, Marc Teboulle

Year

2009

Journal Paper

Algorithm

Fast Iterative Shrinkage-Thresholding Algorithm

Source

SIAM Journal on Imaging Sciences

Identifiers

DOI 10.1137/080716542

Abstract¶

We consider the class of iterative shrinkage-thresholding algorithms (ISTA) for solving linear inverse problems arising in signal/image processing. This class of methods, which can be viewed as an extension of the classical gradient algorithm, is attractive due to its simplicity and thus is adequate for solving large-scale problems even with dense matrix data. However, such methods are also known to converge quite slowly. In this paper we present a new fast iterative shrinkage-thresholding algorithm (FISTA) which preserves the computational simplicity of ISTA but with a global rate of convergence which is proven to be significantly better, both theoretically and practically. Initial promising numerical results for wavelet-based image deblurring demonstrate the capabilities of FISTA which is shown to be faster than ISTA by several orders of magnitude.

Summary¶

Introduces FISTA, an accelerated proximal-gradient method for composite convex problems such as L1-regularized inverse problems. Its simple extrapolated shrinkage-thresholding iterations became a default baseline for sparse reconstruction and first-order optimization.