Image Denoising in Mixed Poisson-Gaussian Noise
We propose a general methodology (PURE-LET) to design and optimize a wide class of transform-domain thresholding algorithms for denoising images corrupted by mixed Poisson-Gaussian noise. We express the denoising process as a linear expansion of thresholds (LET) that we optimize by relying on a purely data-adaptive unbiased estimate of the mean-squared error (MSE), derived in a non-Bayesian framework (PURE: Poisson-Gaussian unbiased risk estimate). We provide a practical approximation of this theoretical MSE estimate for the tractable optimization of arbitrary transform-domain thresholding. We then propose a pointwise estimator for undecimated filterbank transforms, which consists of subband-adaptive thresholding functions with signal-dependent thresholds that are globally optimized in the image domain. We finally demonstrate the potential of the proposed approach through extensive comparisons with state-of-the-art techniques that are specifically tailored to the estimation of Poisson intensities. We also present denoising results obtained on real images of low-count fluorescence microscopy.
- URL: http://bigwww.epfl.ch/publications/luisier1101.ps
- URL: http://bigwww.epfl.ch/publications/luisier1101.html
Keywords: Filterbank ; Gaussian noise ; image denoising ; MSE estimation ; Poisson noise ; thresholding ; unbiased risk estimate ; Wavelet Shrinkage ; Intensity Estimation ; Redundant Representations ; Multiscale Models ; Restoration ; Curvelets ; Domain ; CIBM-SP
Record created on 2011-02-17, modified on 2016-08-09