Orthogonal WT (7-9 filters) + universal thresholding and residual image

Undecimated WT (7-9 filters) + ksigma thresholding and residual image.

Wavelet-domain Hidden Markov Models and residual image. See

M. S. Crouse, R. D. Nowak, and R. G. Baraniuk, Wavelet-Based Signal Processing Using Hidden Markov Models, IEEE Transactions on Signal Processing (Special Issue on Wavelets and Filterbanks), April 1998.

Multiscale entropy filtering and residual image. See

J.L. Starck, and F. Murtagh, "Multiscale Entropy Filtering", Signal Processing, Vol 76, No 2, pp 147-165, 1999.

Ridgelet transform (Block size = 32) and residual image.

Curvelet transform and residual image.

The filtered image has been obtained by using an iterative technique and several transforms: the curvelet, the ridgelet, and the undecimated wavelet transform. Only a combination of methods allows us to clean properly the residual.