Image Denoising in Mixed Poisson–Gaussian Noise

  • Authors:
  • F. Luisier;T. Blu;M. Unser

  • Affiliations:
  • Biomed. Imaging Group (BIG), Ecole Polytech. Fed. de Lausanne (EPFL), Lausanne, Switzerland;-;-

  • Venue:
  • IEEE Transactions on Image Processing
  • Year:
  • 2011

Quantified Score

Hi-index 0.01

Visualization

Abstract

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.