Statistics – Methodology
Scientific paper
2008-04-14
Statistics
Methodology
to appear in the IEEE Transactions on Signal Processing
Scientific paper
10.1109/TSP.2008.2008212
Stein's unbiased risk estimate (SURE) was proposed by Stein for the independent, identically distributed (iid) Gaussian model in order to derive estimates that dominate least-squares (LS). In recent years, the SURE criterion has been employed in a variety of denoising problems for choosing regularization parameters that minimize an estimate of the mean-squared error (MSE). However, its use has been limited to the iid case which precludes many important applications. In this paper we begin by deriving a SURE counterpart for general, not necessarily iid distributions from the exponential family. This enables extending the SURE design technique to a much broader class of problems. Based on this generalization we suggest a new method for choosing regularization parameters in penalized LS estimators. We then demonstrate its superior performance over the conventional generalized cross validation approach and the discrepancy method in the context of image deblurring and deconvolution. The SURE technique can also be used to design estimates without predefining their structure. However, allowing for too many free parameters impairs the performance of the resulting estimates. To address this inherent tradeoff we propose a regularized SURE objective. Based on this design criterion, we derive a wavelet denoising strategy that is similar in sprit to the standard soft-threshold approach but can lead to improved MSE performance.
No associations
LandOfFree
Generalized SURE for Exponential Families: Applications to Regularization does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.
If you have personal experience with Generalized SURE for Exponential Families: Applications to Regularization, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Generalized SURE for Exponential Families: Applications to Regularization will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-654321