Documentation |
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.
sizeINI | Size of the three-dimensional array X. |
mode | Name of the wavelet transform extension mode. |
filters | Structure with 4 fields, LoD, HiD, LoR, HiR, which contain the filters used for DWT. |
dec | 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');