detcoef2 (Wavelet Toolbox)

Extract 2-D detail coefficients.

D = detcoef2(O,C,S,N)

Description

detcoef2 is a two-dimensional wavelet analysis function.

D = detcoef2(O,C,S,N) extracts from the wavelet decomposition structure [C,S] (see wavedec2), the horizontal, vertical, or diagonal detail coefficients for O = 'h'(or 'v' or 'd', respectively), at level N.

Level N must be an integer such that 1 <= N <= size(S,1)-2.

Examples

% Load original image. 
    load woman; 
    % X contains the loaded image.

% Perform decomposition at level 2 
% of X using db1.
    [c,s] = wavedec2(X,2,'db1');

    sizex = size(X)
sizex =
    256    256

    sizec = size(c)
sizec =
    1    65536

    val_s = s 
val_s =
     64     64
     64     64
    128    128
    256    256

% Extract details coefficients at level 2 
% in each orientation, from wavelet decomposition 
% structure [c,s]. 
    chd2 = detcoef2('h',c,s,2); 
    cvd2 = detcoef2('v',c,s,2); 
    cdd2 = detcoef2('d',c,s,2);

    sizecd2 = size(chd2)

sizecd2 =
     64     64

% Extract details coefficients at level 1 
% in each orientation, from wavelet decomposition 
% structure [c,s]. 
    chd1 = detcoef2('h',c,s,1); 
    cvd1 = detcoef2('v',c,s,1); 
    cdd1 = detcoef2('d',c,s,1);

    sizecd1 = size(chd1)

sizecd1 =
    128    128