MATLAB: Wavelet decomposition 2D help with software

Question

I am wondering what is the best way to use the wavelet-2D decomposition package? I am trying to compress some MRI images and wondered how I know which wavelet to choose and what value of 'n' to select etc. Anyone familiar with this package who could help me with this software?

Also I was wondering if I could use soft thresholding instead of hard thresholding

Answer 1

In terms of soft vs. hard thresholding. Only hard thresholding would actually buy you something in terms of compression because you would end up with a large number of zeros. For soft thresholding, you shrink wavelet coefficients toward zero but you don't get rid of them, so ultimately you don't save yourself memory that way.

In terms of which wavelets to use, for image processing generally the biorthgonal wavelets 'bior#.#' are favored in practice for image processing.