2-D detail coefficients
D = detcoef2(O,C,S,N)
detcoef2 is a two-dimensional wavelet analysis function.
D = detcoef2(O,C,S,N) extracts from the
wavelet decomposition structure [C,S] the horizontal,
vertical, or diagonal detail coefficients for O = 'h'(or 'v' or 'd',
respectively), at level N, where 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).
% 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
If C and S are obtained
from an indexed image analysis or a truecolor image analysis, D is
an m-by-n matrix or an m-by-n-by-3
array, respectively.
For more information on image formats, see the image and imfinfo reference
pages.