This is machine translation

Translated by Microsoft
Mouseover text to see original. Click the button below to return to the English verison of the page.

Note: This page has been translated by MathWorks. Please click here
To view all translated materals including this page, select Japan from the country navigator on the bottom of this page.


Single-level inverse discrete 3-D wavelet transform


X = idwt3(WT)
C = idwt3(WT,TYPE)


The idwt3 command performs a single-level three-dimensional wavelet reconstruction starting from a single-level three-dimensional wavelet decomposition.

X = idwt3(WT) computes the single-level reconstructed 3-D array X, based on the three-dimensional wavelet decomposition stored in the WT structure. This structure contains the following fields.


Size of the three-dimensional array X.


Name of the wavelet transform extension mode.


Structure with 4 fields, LoD, HiD, LoR, HiR, which contain the filters used for DWT.


2 x 2 x 2 cell array containing the coefficients of the decomposition.

dec{i,j,k}, i,j,k = 1 or 2 contains the coefficients obtained by low-pass filtering (for i or j or k = 1) or high-pass filtering (for i or j or k = 2).

C = idwt3(WT,TYPE) computes the single-level reconstructed component based on the three-dimensional wavelet decomposition. Valid values for TYPE are:

  • A group of three characters 'xyz', one per direction, with 'x','y' and 'z' selected in the set {'a','d','l','h'} or in the corresponding uppercase set {'A','D','L','H'}), where 'A' (or 'L') specifies low-pass filter and 'D' (or 'H') specifies high-pass filter.

  • The char 'd' (or 'h' or 'D' or 'H') which specifies the sum of all the components different from the low-pass component.


% Define original 3D data.
X  = reshape(1:64,4,4,4);

% Decompose X using db1.
wt = dwt3(X,'db1');

% Reconstruct X from coefficients.
XR = idwt3(wt);

% Compute reconstructed approximation, i.e. the 
% low-pass component.
A  = idwt3(wt,'aaa');

% Compute the sum of all the components different
% from the low-pass component.
D  = idwt3(wt,'d');

% Reconstruct the component associated with low-pass in the
% X and Z directions and high-pass in the Y direction.
ADA  = idwt3(wt,'ada');

See Also

| |

Introduced in R2010a

Was this topic helpful?