A trimmed translation-invariant denoising estimator

作者：Cuevas Jordan P^*; Chicken Eric

来源：Journal of Statistical Computation and Simulation, 2012, 82(9): 1299-1310.

DOI：10.1080/00949655.2011.576677

• wavelets
• stationary
• thresholding
• non-parametric regression
• translation-invariant
• oracle

A popular wavelet method for estimating jumps in functions is through the use of the translation-invariant (TI) estimator. The TI estimator addresses a particular problem, the susceptibility of the wavelet estimates to the location of the features in a function with respect to the support of the wavelet basis functions. The TI estimator reduces this reliance by cycling the data through a set of shifts, thus changing the relation between the wavelet support and the jump location. However, a drawback of the TI estimator is that it includes every shifted analysis in the reconstruction, even those that may reduce, rather than improve, the effectiveness of the method. In this paper, we propose a method that modifies the TI estimator to improve the jump reconstruction in terms of the mean squared errors of the reconstructions and visual performance. Information from the set of shifted data sets is used to mimic the performance of an oracle which knows exactly which are the best TI shifts to retain in the reconstruction. The TI estimate is a special case of the proposed method. A simulation study comparing this proposed method to the existing wavelet estimators and the oracle is provided.

• 出版日期2012