| Wavelet Toolbox | |
Extract 2-D detail coefficients
Syntax
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 for more information), the horizontal, vertical or diagonal detail coefficients for O = 'h'(or 'v' or 'd', respectively), at level N.
N must be an integer such that 1 
N size(S,1)-2.
See wavedec2 for more information on C and S.
[H,V,D] = detcoef2('all',C,S,N) returns the horizontal H, vertical V, and diagonal D detail coefficients at level N.
D = detcoef2('compact',C,S,N) returns the detail coefficients at level N, stored row-wise.
detcoef2('a',C,S,N) is equivalent to detcoef2('all',C,S,N).
detcoef2('c',C,S,N) is equivalent to detcoef2('compact',C,S,N).
Examples
% The current extension mode is zero-padding (see dwtmode).
% 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,cvd2,cdd2] = detcoef2('all',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,cvd1,cdd1] = detcoef2('all',c,s,1);
sizecd1 = size(chd1)
sizecd1 =
128 128
| | detcoef | disp | |