https://scholars.lib.ntu.edu.tw/handle/123456789/640526
Title: | A CURE for noisy magnetic resonance images: Chi-square unbiased risk estimation | Authors: | Luisier, Florian THIERRY BLU Wolfe, Patrick J. |
Keywords: | Chi-square distribution | filterbank transform | image denoising | magnetic resonance (MR) imaging | Rician noise | unbiased risk estimation; Statistics - Applications; Statistics - Applications; Statistics - Methodology | Issue Date: | 27-Jul-2012 | Journal Volume: | 21 | Journal Issue: | 8 | Source: | IEEE Transactions on Image Processing | Abstract: | In this paper, we derive an unbiased expression for the expected mean-squared error associated with continuously differentiable estimators of the noncentrality parameter of a chi-square random variable. We then consider the task of denoising squared-magnitude magnetic resonance (MR) image data, which are well modeled as independent noncentral chi-square random variables on two degrees of freedom. We consider two broad classes of linearly parameterized shrinkage estimators that can be optimized using our risk estimate, one in the general context of undecimated filterbank transforms, and the other in the specific case of the unnormalized Haar wavelet transform. The resultant algorithms are computationally tractable and improve upon most state-of-the-art methods for both simulated and actual MR image data. © 1992-2012 IEEE. |
Description: | 30 double-spaced pages, 11 figures; submitted for publication |
URI: | https://scholars.lib.ntu.edu.tw/handle/123456789/640526 | ISSN: | 10577149 | DOI: | 10.1109/TIP.2012.2191565 |
Appears in Collections: | 電機工程學系 |
Items in DSpace are protected by copyright, with all rights reserved, unless otherwise indicated.