wthcoef2 (Wavelet Toolbox)

Wavelet coefficients thresholding 2-D.

NC = wthcoef2('type',C,S,N,T,SORH) 
NC = wthcoef2('type',C,S,N)
NC = wthcoef2('a',C,S) 
NC = wthcoef2('t',C,S,N,T,SORH)

Description

wthcoef2 is a two-dimensional de-noising and compression oriented function.

For 'type' = 'h' ( 'v' or 'd'), NC = wthcoef2('type',C,S,N,T,SORH) returns the horizontal (vertical or diagonal respectively) coefficients obtained from the wavelet decomposition structure [C,S] (see wavedec2), by soft (if SORH='s') or hard (if SORH='h') thresholding defined in vectors N and T. N contains the detail levels to be compressed and T the corresponding thresholds. N and T must be of the same length. The vector N must be such that 1 <= N(i) <= size(S,1)-2.

For 'type' = 'h' ('v' or 'd' respectively), NC = wthcoef2('type',C,S,N) returns the coefficients of 'type' orientation obtained from [C,S] by setting to zero all the coefficients of detail levels defined in N.

NC = wthcoef2('a',C,S) returns the coefficients obtained by setting approximation coefficients to zero.

NC = wthcoef2('t',C,S,N,T,SORH) returns the detail coefficients obtained from the wavelet decomposition structure [C,S] by soft (if SORH='s') or hard (if SORH='h') thresholding (see wthresh) defined in vectors N and T. N contains the detail levels to be thresholded and T the corresponding thresholds which are applied in the three detail orientations. N and T must be of the same length.

[NC,S] is the resulting wavelet decomposition structure.