Adaptive Wiener Denoising using a Gaussian Scale Mixture Model in the Wavelet Domain

Javier Portilla , Vasily Strela , Martin Wainwright, Eero P Simoncelli

Published in:
Proceedings of the 8th IEEE Int'l Conf on Image Processing
Thessaloniki, Greece. 7-10 October 2001.
doi: 10.1109/ICIP.2001.958418
© IEEE Computer Society.

Full-length papers on wavelet denoising:
  • Bayesian denoising of visual images in the wavelet domain, Spring 1999.
  • Image denoising using a scale mixture of Gaussians in the wavelet domain, Fall 2003.


We describe a statistical model for images decomposed in an overcomplete wavelet pyramid. Each coefficient of the pyramid is modeled as the product of two independent random variables: an element of a Gaussian random field, and a hidden multiplier with a marginal log-normal prior. The latter modulates the local variance of the coefficients. We assume subband coefficients are contaminated with additive Gaussian noise of known covariance, and compute a MAP estimate of each multiplier variable based on observation of a local neighborhood of coefficients. Conditioned on this multiplier, we then estimate the subband coefficients with a local Wiener estimator. Unlike previous approaches, we (a) empirically motivate our choice for the prior on the multiplier; (b) use the full covariance of signal and noise in the estimation; (c) include adjacent scales in the conditioning neighborhood. To our knowledge, the results are the best in the literature, both visually and in terms of squared error.
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